I don't know how many Aurora owners have upgraded there Auroras with some custom wheels? I have on my 1999 Onyx Black Aurora a set of 18 inch Lexani Roma, all chrome wheels with Nitto eXtreme tires size 235/40/ZR18. I also found these website http://www.afftw.com/main.htm were you can load any Olds Vehicle and see what it would look like with some custom wheels. See how an Aurora would look, you can change the color to match your own, you can even drop the Aurora several inches. Make sure you click on the far upper right hand side of the screen were it says "View Wheels on Vehicle" and a new page will load and check it out.
Well, it will be a little while. I ordered the retainer removal tool because it's only $10. However, it will take 4-6 weeks to come in. My biggest surprise was the mechanics just telling me to use a door panel tool or a screwdriver. They don't even have the right tool. I mean, it's ten freaking dollars!
Anyway, this might mean I'll have some time to baseline the car. I am considering the new GTech Competition meter. I've posted on the Cadillac Performance page at GMForums about it. It seems pretty neat. I'll just have to find some space where I can try it out. There's a closed-up Wal-Mart near me that has a huge empty parking lot. Perhaps I'll check that out...
2001 3.5. OK hoseheads, any reports of performance increases w/ K&N and or larger exhaust set-up w/o all this redoing hoses, dryer hoses, shop vac hoses, duct tape, etc? Don't want to go the Apollo 13/"Junkyard Wars" route with my nice upscale sedan; just something relatively simple and cost effective in terms of performance boost.
I'm not "Apollo 13"-ing my car... I was just trying to give a thorough explanation. I haven't dyno'd or track tested the car after the K&N, but Garnes did. He has a classic, and obviously a 4.0, but the results should apply in some way to your car. Check out the Intrigue board to see what sort of results they get from their 3.5's. I'm sure it will help somewhat. They definitely breath better than paper filters. It's just a matter of whether your engine can make use of more breathing. I don't think anyone here has really done much exhaust mods, but I'm sure they would help some too. There are some reports for Cadillac's, but again, they have a V-8. However, their results will probably have some usefulness for you.
Actually, there is one performance upgrade you can do that costs about $2,000 and can be installed with just a pencil. You just check the box labeled "4.0" on the order sheet...
By the way, I'm not using the 2 1/2" vacuum hose anymore. Garnes crunched some numbers, and it will definitely be too narrow. I will try to squeeze the 4" dryer hose in if I can, and if not I will just stick with the K&N and a stock setup. I have to wait for that trim removal tool to arrive, though. I'll keep you all posted (I'm sure you're on the edge of your seats)...
Can anyone recommend good aftermarket suspension components for the front of a 95 classic to significantly firm up the ride? I don't like the wallowy feel of what's there right now. I'd like to leave the back end alone, since it's the air thing and all. I don't want to change the height at all, either.
Also, any idea on the cost? Figure both components and labor.
A few people have talked about this in the last couple of months -- check back several pages. The consensus however, was that there are a couple of things you can do without completely rebuilding the front end.
1) Struts -- I put KYB GR2's on the front of my 95. Firmed it up nicely. Highly recommended. Cost about $120/ea if you can do it yourself.
2) Sway Bar -- Someone on here (Henry?) found that the Caddy STS front sway (anti-roll) bar is a direct bolt-in replacement for the Classic's front sway bar. Probably makes a great deal of difference. Price would depend on whether you get it from your dealer or a salvage yard.
I'm going to put the KYB GR2 struts in soon myself. Haven't decided on the rear's yet. I'll post back with the results. So far, It seems that stock replacement is best for the rears and the KYB's up front. I asked the dealer about if there are different part #'s for my 96 Aurora to a 99, but no. Someone went with Monroe's self leveling rears as another option. Can't remember if they liked it or not though.
As for the sway bar thing, this is a copy of the old post with part #'s.
HENRY- I note in your posting of 27 Jan, #269 that you have installed
Caddie sway bars (plural) in your Aurora. I knew that a 2000 Seville rear sway bar is a direct bolt in (GM part # 25666234) and that gets you a 22 mm rear bar. My 96 Aurora came stock with a 17mm rear and a 27mm front. I have already installed the 22 mm rear bar. Is there a front Seville sway bar that will fit? I know I can put in a 98-99 Aurora bar which is 29 mm but if I'm going to do it I might put in bigger if something is available. Thanks in advance for your info. To other readers: I also put in polyurathane end links and center bushings on my sway bars F & R and you could tell an immediate difference. Also KYB struts up front. Would recommend both the struts and bushings to anyone who wants to tighten up his classic Aurora.
When I asked about the shocks, I also asked about the sway bars. They had no info on the 99Aurora swap and wouldn't comment on using Caddy parts on my Olds. I didn't look to far into it, no measuring of anything but I most likely delt with a lazy Service/Parts guy.
It probably can be done. I wasn't happly concluded with my search on the sway bar thing, so I went a different way, an alternative. I bought RSM racings Front Strut Tower Bar http://webhome.idirect.com/%7Ersm1/aurstb.jpg (the black box on top of the bar is only on early 95's,btw). I Installed it 2 weeks ago and noticed the improved tightness in the first turn. It makes the Aurora want to carve into those turns, not "roll". The front end stays parellel to the road more than ever. Deffinently tightened up this classics body roll. My girlfriend noticed a difference too. Now she wants one for her 96 Accord. I think it was well worth the $289 to firm up the ride, I would pay the $199 for RSM's rear bar too http://webhome.idirect.com/%7Ersm1/aurrstb.jpg, if I could get it too fit into my trunk around my Custom 800 watt system taking up half the trunk. The ride would be even tighter then. I think it would fit infront of my false wall in my trunk, but I have to take the wall down any time I want to work/tune my system so I'd have to take the strut bar down evertime too. Oh, well. I thought about it and decided not too, I value what little trunk space I have left, from an already small tunk in the first place.
I recommend www.rsmracings.com front strut bar. They also sell there own bushings and mounts for a couple of places, might look into that too. They have more available, than whats listed.
Note:Because I have a tendancy to speculate on things, I will put everything that I learned specifically from my call to Corsa in bold. Everything else is my interpretation or speculation.
Anyone (especially if you have a new Aurora) that is interested in the Corsa exhaust, you should call Corsa first. (I know, everyone says talk to Jim Browning, but I just said I had questions and figured I'd talk to whoever got the call. I bet they are all pretty knowledgable people, and we'd never know what the rest of the team is like if we all talk to Jim ) I spoke with Paul (Santiago, I believe) from Corsa today, and he said they have decided to put together an exhaust specifically for the Aurora. Now, it's possible that they won't do it for the classic, but I don't know. I don't own one, so I was more interested in the new Aurora. If you have a classic you should call them. At the least, though, if you have a classic, the mufflers they design for the new Aurora might be better than the ones designed for the Caddy.
What he said was the Caddy system would fit the new Aurora with some slight adjustments, but that the tonal quality probably wouldn't be the best. Because they tune their exhaust specifically for an engine, the Northstar wouldn't be ideal for the Aurora. He said you would get the performance (it's still open and straight-through), but they wouldn't be happy with the quiet. He said they tune it for a quieter cruise than stock. Basically, all the sound should come out the back with no resonance inside. When you open her up, then there is enough sound out the back that you can hear it inside, but at cruise it should be quiet.
They may or may not go with the tips they use on the Caddy. He said they have another possibility in the works (he said it was something they tried with the C5...). Not sure if it's tips they actually use on the C5, though. They have couple different ones. Maybe those mega tips from their titanium mufflers... I think that would look a bit garish on an Aurora though.
Garnes, I wonder if you noticed some cruise note because the Cadillac has a bigger engine. I wonder if there is a cruise note anyway with the stock setup. I've yet to drive in a stock Seville. But the engine is noticeably bigger. If you'd ever been in an 80's Camaro with a 305 and then one with the 350, the exhausts are basically the same, but the 350 definitely sounds bigger. It's possible the Northstar has some cruising sounds that we don't get with the Aurora. Paul really stressed that the Corsa should be as quiet or quieter at cruise. Maybe the Corsa cruise note is actually quieter in terms of decibels, but is a more distinct sound so you can more easily distinguish it from other road and wind noises... I'm just speculating and opining here, so take with a (large) grain of salt.
However, I fully expect the exhaust they develop for the Aurora to be perfectly liveable at cruise, and I fully expect to buy one as soon as they finish it. In fact, I was calling to get a few questions answered, and then I was going to order the Caddy system. Their exhaust is made to be clamped and self-installed. This is great as I have had poor luck with any exhaust shops around me. I did a few changes to the 'vette, and each place I went was less than perfect. No horrible disasters, but I was never completely satisfied. They'd either cut up some pipe I didn't want them to, or ruin the piece they were taking off, or try to snow-job me into getting other replacement parts that I knew I didn't need. So, if I can do it myself I will be quite happy. Plus, it means the stock system can be put back on for whatever reason.
rjs - Thank you big time for the info. I'll try to find out what this means for the classic.
From what you said, it's definitely worth waiting for something tuned for the 4.0. I'd guess the same as you - it's for the new 4.0, but it should be workable for a classic. However - Jim Browning told me they have put a system on a classic. If they "digitized" it as they made it, then they have the information computerized so that more can be made. Of course they have put one on the new 4.0 as well now.
As for quiet cruise - well they key is at what speed. 60 mph - yeah I think they are probably right about no noise. Over 70 and the rpms start to climb a little with the 3.71. Things change. Again, the STS I drove in when I visited (Jim Browning Sr.'s) car had a little note in the car at 70 to 75. It was slight. You had to be listening for it like I was, but it was not intrusive. Going up an overpass and yes - it got louder at 70+ Going down and it's gone. Flat surface - very slight note.
If you want to fly 80+ I'd expect more of a note in the car.
Yes, I agree, the 4.0's smaller size should make for at least a slightly quieter exhaust system than the 4.6. The Aurora is certainly every bit as sound proof as a Seville so I'd expect it to be quieter.
what they say about the classic. I think they are going to design the whole system, though, not just pipe lengths and bends. The system you said they put on a classic, and the one they put on the current Aurora used Northstar mufflers. Paul said they will design the mufflers specifically for the 4.0 Aurora, so it isn't just getting the dimensions to fit the new Aurora. I'm sure it would work better for the classic too. It's pretty cool that someone out there actually cares about our car, though! Especially with Olds pulling the plug.
RJS - Oh yeah, definitely more than just the plumbing. Jim told me they model the mufflers and resonators and like you said, they do try to customize the sound. The original STS system has had improvements. I remember him saying that the Tim Allen 398 HP Deville's system was louder than the one currently sold - they refined it.
Yep - anything that has gone on an Aurora thus far has been a Caddy system.
Doing something for an Olds - this really doesn't surprise me. I will not be surprised if they do this for the classic either. The new Aurora is a no-brainer. It supposedly is about the same as the current STS, so the plumbing is practically already designed. Any muffles and resonator developed will automatically have you a new Aurora system. You should have one for sure.
About the classic - they made these things for 5 years. I'd guess there are over 125,000 originally out there. Perhaps 150k. That's not too bad, but certainly not a lot.
However, here is the key - It's a "cool" looking car with an unbelievably wide range of appeal. The new Aurora is nice too (I personally like the front better and the chiseled bulging sides are just about as tough as the classic, maybe better depending on your opinion - the back - well it gets a C - the rest is an A). The classics can be had for a very reasonable price now given their age and mileage. A lot of younger people are scooping these up now too because it's just a cool car and are interested in opening up some of that V8 potential. I think a lot of the classics are going from 50 something first owners to 20 or 30 something second and third owners.
Oh - and they tend to be well taken care of and not abused either.
So, there may be a market out there and they already have the groundwork on the 4.6. That's my theory at least.
I think it's a done deal. I'm buying this if/when it comes out next spring whether I have to modify the new Aurora system with a custom visit to Corsa or not.
By the end of 2003 when the last Aurora has rolled off the line, I would bet there are more classics than new Aurora's out there. Definitely more V8 classics than V8 new ones. The Aurora isn't selling the way Olds hoped. At least not since they announced Olds' death. So there is probably more of a market for a system for the classic. I wonder if more fogies buy the new one than the classic. When the classic came out, the feebs could still buy a floaty 88 or, for a few year, a 98. Now, the fogies could get an Intrigue, but that really isn't a floaty old-person car. So they might find more appeal in the extra bulk of the Aurora.
I would think if the Corsa mufflers are optimal for both then there would definitely be no reason not to offer a system for both. All that would take is a little pipe bending.
I wasn't all that keen on the rear styling of the Aurora at first either. It has grown on me now, and it is distinctive if nothing else. However, it does seem like they tried to keep some heritage there by sloping it like the classic, but it doesn't work nearly as well on the more edgy shape of the new car. It definitely looks better on the smooth flowing line of the classic. The only classic design that I would do a little different is that strech of "lights" that runs across the trunk to look like the taillights run all the way across. That's the only part of the design that's dated to me. It says "early 90's" while the rest of the car is a more timeless sleek design. The hood can look a little long from some angles, but I think if they shortened it, it would look dumb. Oh, I also prefer full-framed doors because otherwise the glass always feels like it's getting bent or something when closing the doors. The classic definitely has a cool look, though. It's a luxury performance car, and it's look totally says luxury and performance.
Definitely will be fewer new models on the road than classic's. And I am noticing that the majority of the new model's are 3.5's. I can only guess it is because the 3.5's are in service as rental cars and quite a few are at that 20k mile range where they get auctioned and shuffled into the used car market. (see my post on 2001 records on the main board) I've also been thinking that anyone who had a Classic couldn't possibly be satisfied with a new 3.5. Drove both and felt like I had driven two totally different cars. The 3.5 simply didn't hook me at all.
A couple of things kept me in the Classic arena. I like the styling of the new Aurora, yet it is not as distinctive as the classic. It sort of blends with the Lincoln LS and a few other current models.
To me, the feel of the classic is more solid, the build feels more robust. I know they say the interior and cargo space is nearly the same, but the new Aurora feels smaller inside, more cramped when passengers are on board.
But the deal breaker is the price. Even with rebates and dealer discounts, a loaded 4.0 is nearly double the price of a 99 Classic in exceptional condition with under 30k miles.
As for fogies, I tend to agree that 1st owners of classics may have been past their mid life crisis. And they didn't buy the car to power around the back roads or challenge BMW's on the interstate. Rather they purchased a refined top of the line American car. Advanced with it's head turning style, luxury, technology, and all those cool buttons and switches that turn the cockpit into a visual experience at night.
2nd owners may be younger with less purchasing power and savvy enough to see the incredible amount of car that can be had for the dollar. Plus, a little younger often means a little more willing to take risks. The Classic's have a risky image, thus the reason most used car buyers seem to avoid them. I've been lucky with my used 95 so far, but have to admit that the slightest stumble or a sound I don't think I ever heard before scares the heck out of me.
The horror stories posted on these boards don't help the image, nor my comfort level. I want to believe that since my 95 was a one owner, traded in at the original selling dealer by an over 60 fogies makes it a safer bet.
And I sometimes "hope" that the mechanical failures I read about just might be influenced by a driving style enjoyed by the younger riskier 2nd and 3rd owners.
You got a website? What's the web address? Let me dig up a picture of my Intrigue that I had with some custom wheels before the Aurora that I have now. I'll let you know.
There is a board under this Owner's club to post pictures. I would ask that you guys consider posting your pictures here on Edmunds also. That way we can see each others Aurora. By the way, it might be a nice idea to nclude yourself in the picture. I want to see that AURORA SMILE!
Henri, I don't think you can post pictures on the Edmunds board unless you have it on another web server. Most free servers, like geocities, don't let you host pictures for display on other sites. So I can't display the pictures here unless I were to spend money for a server (or for a static IP so I could have my own server, dang DSL).
Feebs - now I'm laughing. That just cracks me up. "I'm cold and I don't know what time it is - dang blasted where did I park that Aurora"
I'm sure plenty of Classic Auroras graced the parking lot at the post office first thing in the morning - and the bank.
It's true, I still see a lot of really old people tooling around in the Aurora. It's cool really.
I like the tail of the classic. It's clean and pulls the whole thing together in the back - very few cars look as clean from the back. Generally, it's the more lines, shapes, and colors, the better. Each year it gets more grotesque. Now we see the goofy after-market looking tail lights coming from the factory. Ug.
However, I'd trade for the front of the new Aurora any day. The classic front end is so bland from a dead on view. Those air vents/grills/whatever on both sides do it on the new one.
Oh - to keep this topic legal - Jim Browning e-mailed me that the Corsa system will be for the new Aurora. If I have to wait until next spring to find out they won't custom fit it to the classic until the following fall - well that blows. I'll try to find out more.
I'm going crazy - all weekend someone or several people were driving by the cross street a few houses down with the sweetest exhaust systems. Not loud, but really nice. It was like smelling a T-bone on your neighbor's grill when you are really hungry (my neighbor does that too me all the time).
I talked to a Paul Santiago at Corsa. The Aurora exhaust system they will develop will be for the new Aurora only. According to him, the Seville system sounds great on the classic but produces distortion on the new Aurora. Apparently, the differences in the engines is significant and the different sizes in exhaust valves (I think that's a difference) affects sound. He indicated that the new exhaust system might be available this fall (who knows).
Another interesting note - the mufflers will be the same as the Seville. The resonator is what is "tuned". Paul said the resonator is what controls much of the sound.
RJS (or anybody else) - please add anything you know about the differences in the valving on the two 4.0's. It's pretty interesting how these engines have very different personalities. I'll bet the new Aurora stock exhaust sounds different than the classic too.
Here are the cam and valve specs for the new Aurora. Since I don't have a classic, I have no need for a classic service manual. Hence, I don't know the specs for the classic. Anyone who wants to look them up and post them, that would be great.
Lift is 6.15mm (.2421") intake, 5.94mm (.2339") exhaust. The rockers are 1.68:1, so that gives the actual valve lift. The valve sizes are listed in the camshaft specs as 10.5mm intake and 10mm exhaust. However, this seems impossibly small once I thought about it. That's less than 1/2" wide. Under the valve specs, there is an entry for exhaust head diameter which is 27.880-28.140mm and the intake head diameter is 34.090-34.350mm. This seems more reasonable for the valve sizes.
Supposedly that's a bigger intake and smaller exhaust than on the classic. The bigger intake should improve breathing at higher rpms, and the smaller exhaust valve will speed up the exhaust flow (since the same amount has to get out a smaller hole in the same amount of time). I believe this is better at lower rpm, and was done more for clean running than performance. However, I'm not sure. Plus, without knowing the cam timing, this is only one part of the equation.
This statement about the redesign of the Northstar might help since they both got the same redesign:
Revised combustion chambers are superior to previous designs in terms of both tumble motion of the incoming fuel-air mixture and burn rate. The intake and exhaust valves have been resized. Larger intake valves improve the engine’s breathing ability, while smaller exhaust valves increase flow velocity, an aid to catalyst light off.
The Olds site doesn't go into this much detail about the redesign, but I really think the same things were done to both.
Taylor, The system that we have done is for the newer Aurora's. The same basic system that we build for the STS also fits in the newer Aurora's. We did not have to do any new tuning of mufflers for this car at all. Just the tubing lengths had to be changed to make it fit.
We have built one system for a 98 Aurora. It sounds very similar to the STS. At this time, we do not have plans for building a system for the older cars, just not enough demand.
Some people have talked about buying an STS system and having a muffler shop fit the system to the car. It will require some new pipes to be bent to make the system fit.
We do not have time to custom build any more of these right now. Maybe in the fall.
Thanks, Jim
Well, what to do now? Time to go and get some custom bent exhaust estimates. Still want that Corsa sound though. Hum.
800wattAurora - just wait until fall and have a custom job by them. It's only a few months and a few hundred miles.
If I do this, I'll make the trip. Take note here - when I was considering this before, Corsa said that while I would be there, they may be able to knock out 2 systems if anybody else wanted one. So, this fall, maybe one of us can go and get both made. Just a thought.
ALSO - I don't want to tick anybody off a Corsa so I'm not going to start hassling them about it, but RJS and I have both talked to Paul Santiago at Corsa and he specifically said the new Aurora did not sound as good as the classic with the Seville system. Therefore, Paul said they will make a resonator specifically for the new Aurora. I guess it has to do with the fact that the exhaust valves on the new 4.0 are smaller and this changes the sound. Whatever. I don't know why there are two different stories from Paul and Jim.
Paul also said the Seville system sounded great on the classic and confirmed that nothing is in the works for the classic unless you had it custom fitted.
How old is that message from Jim? Did you read the latest posts on Corsa? It's like Garnes said. For the classic, the Northstar system works fine. For the new Aurora, they are making some changes and it should be out next year. Maybe you talked to him before they decided to make a system for the new Aurora.
If you buy the stuff now and have a local shop hook it up, make sure they use good equipment. The system should use mandrel bending or some other type that doesn't restrict the flow. Those ripply bends narrow the pipe at the bend and cause a constriction.
If I were to do Corsa, I would drive the car there and let them do it. I would not invest in a quality product and then let the local Midas shop or mom and pop put it in.
Spend $1,000 on the product and $250 for the "professional" labor?
Where to begin, I've been so busy at work the last 10 weeks or so, I've been working 60-72hr weeks. Having trouble finding spare time work on the Aurora during the sunlight hours. I did get the first wax/detail job on my white classic beauty this last weekend. I got off work early today, So I have some time to catch up on my posts.
First time I used a "polymer wax" made out of Teflon. IT"S. GREAT. I used to use Meguires religiously, never again. This wax is the best I've ever used. Nothing sticks to the car any more. It's rained 3 times on the finish and still no water spots and still shines brightly. Water doesn't bead-up, it just sheets right off. Someone asked me yesterday If a garaged my car because it looked so clean right after it rained. I don't, I said good wax. Find some Teflon compounded wax and you'll never go back. I'll post back with the name of it, I've never heard of it before. It was sent to me by my old neighbors who moved to La Quenta, CA (outside of Palm Springs). Marty uses it on his white LS 400 and the wives blue BMW Z3. He said everybody out there use's this stuff because it's the BEST. Any ways, enough about the wax already.
First, I realy needed some new tires a couple of weeks ago. So I did some thinking, do I like my stock alloy rims? Debating on some custom 17-18's or keeping the dull stockers. After looking at the pros/cons of up-sizing rims and the cost of low pro tires and keeping it looking like a Luxury car. I decided to call AAArims and chrome rim exchange my dull stockers. The chromes looks SO much better. I've always liked the classic's chrome rims, even before I got my car. The rims arived 2-3days later in A+ condition, only two knicks that weren't taken out before they chromed them. I have no complaints at all, they look great, especially for $650. Ended up going with Dunlop Sport A2s for tires. So far about 400miles on them and they are also GREAT. Way better then the old worn out Eagle GA's. The Dunlop's have a traction rating of AA and tread of 420. Got them at JustTires for $560 with Alignment and road hazard pkg. Free replacement and alignments if problems and Free Tire Rotations for these 50K waranted Tires, through them.
Before when I was thinking about what rims and tires to buy, I thought about my suspension. If I throw some struts on before the tires, I could do it all on one alignment. So that's what I did. Found a set of KYB G2's for $62 each plus two new KYB boots for $10ea at HTTP://WWW.PHILSINC.COM. (Cheaper than tirerack's $70ea) Phil's happen to be in the burbs of Chicago too, thats where I live, so I went and picked them up too. Ended up getting the KYB's put on for $40ea at a Midas that my buddy works at and then drove it strait to JustTires for the Sport A2s and the new chromes and an alignment.
So, now the Aurora is riding and styling better than before. I also recomend the Strut tower bars from RSM. The ride is nice and tight now. As for the RSM Intake and TB, I unfortuneitly can't work out a convient Dyno time with my long hours at work. Probably going to split a new G-tech Comptiton or ap-22 meter with my buddy John who has a 94 Mark VIII, 75 Corvette 350, and 69 Camaro SS 350. His father has a 99 STS that we'll test that out too, along with my Mothers 99 Monte Z34. Seems to be the best bang for my/our buck. The two dyno places were also booked for 3-4weeks and cost around $220-250 for 2 hours. So i'll be ording one of those performance meters this week, but Which one?
Feed back everyone!!! AP-22 or new Gtech?
I figure the the best time for me to get a good baseline is before I need to arrive at work at 6am. Found a Frontage road entrance to a highway 2 minutes from my house. It's a nice strech of road thats flat, long and empty a 5:15 AM and with no places for cops to hide. Might end up testing out the Intake kit and Ported Throttle Body in 0-60 times only on the day of install. No good/safe places to 1/4mi in Chicago going 0-90+ multiple times testing each piece with numerous runs. But that next morning I'll be out there 1/4miling untill I'm blue in the face.
Garnes, count me "IN" on the CORSA tag-team exhaust install in the Fall. SERIOUSLY!!!
Let's try to set a date with Corsa in a couple of weeks. It would be cool to finally meet you, or anyother fellow Aurorians that post here. Time will fly-by while we shoot-the-bull in the waiting room for our custom install's at CORSA. Where do you live? We can compare our mods and you can test listen my 800watt system that I love to talk about. I've also been looking at a possible ram-air set-up location. More about that later.
800wattAurora - I live in the Indianapolis area. What I meant was that it's possible that if one person goes, they can custom make 2 units at the same time. As long as they have payment ahead, they will make the second unit and ship it to the other guy. I talked about this with Jim last fall when I almost did this.
Anyway, I agree with Henry about having Corsa custom fit it. Jim also said we will have to wait until fall when they slow down. I'm not sure any date can be set now. Hopefully by October/November they can do this. That's really not long at all.
800 - perhaps it would be pretty cool if we both met up at Corsa. You never know. I/we should post a bunch come fall and coordinate something. We'll probably have to talk.
Dyno - you could just make your improvements - all of them and then do one dyno. It should give you a general idea of what is happening. My baslines were 189 to 192 HP at the wheels for a stock car with a clean paper filter. I even have the atmospheric conditions for those days too I think. As long as the car is well taken care of, I think the car should perform pretty consistently with 20k miles or 80+k miles. I'm also assuming you'd be dyno testing on the same/similar equipment under the same SAE standards.
I would probably dyno the Corsa too just for the fun of it, so that would give you more information to deduce the increase from any other improvements you have made.
With the Corsa and a simple K&N I expect the 4.0 to make at least 270 HP, and 275 may be more likely - maybe even a little more. With the throttle body and improvements to the intake, I think the engine could produce 280+ HP. That's probably all it's going to do without major money thrown at internal engine improvements. Quite frankly, that would be plenty of power to keep a smile on my face all the time. I'm pretty happy now with just some intakes mods and a K&N. The darn thing moves really well as is.
My nod goes to the new GTech Competition. Did you read my info from GTech on the Caddy Performance part of GMForums? Give them a call if you want more info. It seems like the GTech can download every sampled point of the run, so a program could be made to determine just about any peice of data you want. Plus, it has that RPM sensing and plots out the power and torque curve for you over the RPM range, not just a peak reading. It really seems cool. Make sure you talk to them if you want it to do a specific thing. Make sure it will do it. They are still developing it, so it doesn't do it all yet.
I think there are definitely limits to what you can gain with bolt-ons too. If you could get 275 hp out of it, you'd be doing great. Really, that's like the SLS or ESC except with less weight and better gearing. The Shelby Series 1 only makes 320 hp and that thing is cammed like crazy. It doesn't make that power until 6500 rpms. It doesn't have intake or exhaust restrictions for a quiet ride, and it also has internal improvements like the camming. In fact, Shelby was hoping for a bit more power from it. Although, for a 4.0 liter engine that still needs to make low-end power in a street car, that's pretty good. It also only gains 30 lb-ft and it too is at a higher rpm (5000 rpm). Since the Aurora isn't going to make power at 6500 rpms, the torque gain is the most telling. So I would think that without any internal changes, gaining 30 lb-ft would be a great achievement, and perhaps a little overly ambitious. Even if you gained 30 lb-ft at the torque peak, and say 25 lb-ft at 5600 rpm, that would be a gain of about 27 hp @5600 giving you 277 total horsepower. I have to say, I can't picture getting this much or more with just some bolt-ons. You really have to take most claims with a grain of salt. That is just my opinion, though. But I think you could gain enough power that the bolt-ons are worth it. If ultimate horsepower is your goal, though, you need to open the engine up.
I also think there is some diminishing return. Like adding the K&N frees up the breathing. Cutting the screen off the MAF might a little too, and so might a bigger throttle body. Suppose any one of them frees up 10hp, then I don't think all three would free up 30. I think all three might do 15 or so. The engine only needs so much air. Supposing the stock airbox provides 90% of that, then there is only room to gain 10%. If each individual mod can gain 8%, they won't gain 24% together. I'm making this stuff up, but my feeling is that there is only so much to be gained. I think as you free up the intake and exhaust, the amount you can improve with the next bolt-on is diminished. Now, if you can get cooler air in, then that is a bit different because you are putting denser air in. The exhaust diminishes too in my opinion. There is only so much more power the car would make if it had open headers. Lets say it could free up 15 horsepower. Suppose the Corsa or a high-flow cat gets you an extra 10, then adding the other would probably just add 2-3. Anyway, that's just my opinion. Just to be clear, I totally made up the numbers in this paragraph. They aren't based on anything at all.
First off I want to say that I love my Aurora. Period.
Rjs-Thanks for your vote for the G-tech Comp. I always read the caddy forms after I checked out the Aurora boards. So I catch most of your posts, thats were I first heard of the new G-tech. Sounds like it will be the breakthrough for Performance meters, if I actual can do everything they claim it can do with precision accuracy and be repeatable. Anyways, I think that my buddy and I will split it and test it out for fun, I'll come up with some ram-air&heatshields that I can test out.
Next topic, that -Tbadra- guy has some interesting ideas, huh? That was pretty funny on the -Performance for STS???- topic. What do you think about some of his ideas? They don't all sound bad, but his performance claims are outragously high. Some of them don't apply to the GM Northstar V8 motor like they would to most all GM V6's 90blocks (he ASSumes wrong). Where's the time slip that he just ran? Counting chickens, ha-ha.
Garnes-I wasn't aware that you ment they would make 2 exhaust and ship 1. Personally I want CORSA to do my install, I don't want the customized kit for $1000+ and have Midas put it on. I'll enjoy the road trip with my Girl. We should DEFINATEILY meet up in the fall for the install, let's give them till August 1st and try to set something up.
Dyno&More-I found A place 5-blocks from my work that customizes Imports, http://www.apgperformance.com they had a sign outside for 2 dyno runs for $50. So I went in and talked to them. The parking lot was fully riced out, my Aurora was the only American car and V8 in the lot. There was one car I would trade in the Aurora for though, A NICE Flaming Orange Toyota Supra Twin Turbo fully riced-up, Supra's are the caddys of ricing . Anyways, waiting for my turn in line, the guy infront of me was interested in a chip for his 94 Integra. Any mods he asked? Intake, Exhaust, Piston&;Cams, Polished Type R intake Manifold, Crank shaft., Air fuel something and something else. He wanted to know the performance gains with his V-tech, He asked whats the rev-limiter? 8700RPMS Now!!! Could go up too 9800rpms if he wanted or NO-limit, SUCIDE SHIFT. (Thats Insane) Anyways the guy said we can have one in 2 days programed with his mods and he could go and hook-it-up test drive it before he bought it. Good Customer service, drive it before you buy it. It was a very interesting conversion. Next in line, My turn, The 50$ for 2 runs is for a Baseline and a re-confirming run. Dyno tuning is $80per hour. So I said Sold. 2 HOURS PLEASE. When, He said tomarrow? I Have plans this weekend so I Got next Saturday July 6. I also haven't gotten the right tools for the job yet. You need a star key set to take off the Throttle Body and I don't have my own Torque wrench. I Looked at Star Sets yesterday at PepBoys, slim selection, but I bought a 16pc set T10-T65. Only the T20 fits one of the bolts. I need one between T45-T50. That pissed me off. I'm going to return it and just by the T20 and the T47 that they only sold seperatly. PepBoys rents tools too, they wanted $60 for the tourque wrench, I'll buy a good one for a little over $100. I have one at work, but I can't borrow it because we only have 1 and the night shift might need it. So I also asked APG if I could use one of their Tourque wrenches while I was there, the guy said SURE no problem. You can use what ever tools we've got. Call me next week for the time and directions to our other building.
So I guess I should put in clean paper filter, since I have K&N panel for a STOCK baseline, right? My K&N has over 9,000 miles on it, I've cleaned it a couple of times but never re-oiled yet. I think I'll test with hood open on all runs. They also Said they could do Air/Fuel ratios too for more $$$. Is it worth it? I didn't ask how much. First test baseline, than RSMracings Intake kit w/ K&N Cone, than add the ported 80mm Throttle Body for the total gain. Don't think I'll test just the TB vs. Stock. Hopefully I can get this done in 2-hours. I asked my father to come and watch/help, he said sure, I'll supervise and make sure you don't srew anything up on that fancy car of yours (he drives a 97Escort wagon,doesn't care that he drives a grocery getter) And I'll even hand you the tools and read the manual out to you son. What a guy.
I figure that Total gain should be around the claimed +19hp for Intake & TB. That sounds about right for V8's that have been opend up comparing it to 5.0's & 5.7's. The exhaust should help compliment the intake for a few more hp, probably between 10-18hp, I might as well go back for one more dyno for my cars current/finale horsepower. I'll most like build a heat-shield and ram air device to help achieve that amount of Air that I it got with the open hood dyno. No gaines really expected, more efficency.
The nice Corsa chrome tips will give me a nice slighlty midified look and have a great sound coming from them too. In the end I'll be happy with any noticeable gain and the good looking/sounding exhaust. I want to go for a run at the track when it's all done in the fall just for the hell of it.
I don't think it's going to turn into a rocket when I leave or anything, I just want to add a little more umph to it. The 250HP is nice now but a more=faster. The hopeful 270-280+hp when I'm all done with these mods plus a Corsa exhaust in the fall will make me smile even wider everday when I drive my baby.
This 96 Classic will be my FIRST time drivng down the drag and making dyno runs. This is my first car that I've ever fully paid for, modified performance wise, and invested $1000's in stereo equipment. Hopefully I will own many nice/fast cars in my life and be able to afford to due whatever I want to them. Well you guys know my plans for my first documented modifing.
That sounds great. Glad you found an affordable dyno place. And it sounds like they are good people.
Talk to GTech before you buy it so you know what you are getting into. It will be a cool product, but as of right now they are still making changes. If you buy it now, you'd be a beta tester. There's nothing wrong with that, but you should know what you'll be getting.
You said you have cleaned your K&N many times? I assume you just mean knocking crud out of it. If you've rinsed it off or used the cleaning spray you have to re-oil it or it won't filter anything (except maybe rocks, matchbox cars, and other large objects). Also, it doesn't need to be cleaned very often. If you are just clapping it out, no biggie. If you are hosing it off and such, you might be shortening it's life expectancy by cleaning it every few thousand miles.
As far as those bolt-on gee-whiz electronic gizmos, I've done most of those to my Corvette and the most noticeable difference they made was in making the car run less smoothly. The custom MAF and custom chip just made the engine quirky and prone to knock in hot weather. Underdrive pulleys killed the alternator's ability to keep up while idling. If you had the defroster and headlights on, the car would practically stall when stopped because of the low voltage. Low-resistance wires and a high-output coil didn't make any noticeable difference except in radio performance. The 160 degree thermostat made the heater almost worthless in the winter, and it does hurt oil life. If that GMForums person thinks water isn't a product of hydrogen rich fuel and oxygen rich air, then I think they just don't want to see it. I assure you that water gets in your oil from the combustion process and that if the oil doesn't get hot enough it won't burn it off. That's why short trips can shorten the oil life. It's because the oil doesn't ever heat up to it's proper temperature.
It's funny you mentioned TBadra. I was of the impression it was a chick, not a dude. I was most amused by her "science and logic" argument that amounted to saying the engine is : -spark -air/fuel -compression -computer and that was it. That is neither scientific, logical, nor even an argument. It's just a list of words. She didn't expand on it or explain it in any way. It was basically at that point that I figured I couldn't win. I can't argue with someone who doesn't make logical arguments. Of course you can't tell someone they aren't making an argument, or that their argument isn't logical. They obviously think it is or they wouldn't have offered it in the first place. And there is no point in creating conflict on these boards.
Really what I have a problem with is the idea that there is essentially free power in an engine. Like in the years spent developing a new engine, none of the engineers thought of trying these simple power-building techniques. While there is usually power to be made, it usually also has a trade-off. If someone can point out the tradeoff the engineers made to compromise performance for some other reason, then it's much easier to see how you can gain that power back. It's easy to see that the Aurora had to be real quiet, and if you don't mind a little more exhaust noise or intake noise, you can improve the flow through the engine. That makes sense to me. However, when some product (like a computer chip) claims to make 20-30 more horsepower with no downside, that's hard to swallow. The powertrain engineers have a much more intimate knowledge of the engine, and they spend about a year developing the programming. Some chip company probably spends about a month. It might make more power, but if it does, it is almost certainly because it allows more knock, requires a higher grade fuel, or just worsens the drivability. The thing with the thermostat was pretty absurd. If all that matters is the engine is cool, then why use a thermostat at all? Let the engine run at 100-120 degrees and see what happens... There is a reason cars come with 195 degree thermostats, and there is definitely some trade-off to a lower temp one. If you are aware of the trade-off, and think it is worth it, then fine. But there isn't too much free power out there...
1. Cleaned but have not re-oiled the K&N. HOLD ON HERE. I hope you mean that you just brushed it off a little and knocked the bugs out. If you applied the K&N cleaner and literally washed the dirt and oil from the filter, but have not re-oiled the filter, the filter IS NOT filtering much any more. It has to be oiled with K&N oil as per their directions. If it's not oiled, you are hurting the engine. Dirt is getting in there. The oil is what makes the dirt stick.
2. Your dyno plans seem good to me. Yes, get a clean paper filter for baseline. It is a must. Paper filters block off pretty quick compared to a K&N type, so a slightly dirty one will probably lower the baseline. You might be surprised how long it takes to get out of there.
3. Corsa. Last year, they did not have time for me to visit until well into fall. I'm not to sure about August 1. That may be early. Jim told me "fall" again this year. I agree about having Corsa do the work. But, if you go, I may sponge off of your visit, however I may just visit myself as well and meet you there. I really would want them doing the custom work as well. It's good that they have done one other classic now so they know the bugs. I'd also recommend having them "cut-up" the stock system so you could put it back on if you sell it or whatever.
4. Gains - I have to agree with RJS about diminishing returns - especially with improvements made on the same end (all intake). To illustrate, just consider this - you could remove the entire air box and filter and intake tube (assuming you could still hook up the temp sensor somehow) and dyno it. Just run it with the MAF and TB naked. You would get a certain gain. This gain will be less than the reported gain of each individual improvement added separately. With the stock intake being restricted, any one improvement will be greatly appreciated by the engine, but the second one will add less, and so on. It can only make use of so much air - especially with stock exhaust.
Don't get me wrong though - I expect the TB and intake to certainly better than just one. I'd think the intake makes the biggest difference. I think 270 is easy to get with the exhaust and intake, but perhaps 280/low 280's is about the limit no matter what else you do. Again, this is just opinion. You never know. Also, consider this - the 71k Mercedes S430 does about 275 HP/295 torque. It weighs over 4100 lbs too. A slightly modified Aurora is on par with this engine performance, but of course with a totally different character for sure.
5. I HIGHLY recommend using Mobile 1 or at the very least some new oil before hitting the dyno. You are running it hard on there. The M1 may help everything run better. There is a difference between M1 and conventional oil at those extremes. Also M1 has better performance than other synthetics except for maybe AMSOIL. A new oil filter will ensure the best oil flow and pressure too. Use a good 93 gas as well.
6. Don't forget to plug the temp sensor back in. It will screw up the whole day.
7. Cleaning K&N filters. After washing, I'd let that thing stand in a corner for a week to make absolutely sure it is bone dry before applying any oil again. I would not want any moisture interferring with oil distribution on the filter.
8. You are going to get busted for the "rice" stuff. Just use some other vegatable - we'll know. We have a place right near my office called extreme imports. They have outrageous crap-box cars. Like RJS said, they have a 15k to 20k car with 10 to 20k spent on the car. They could have just bought a used Vette, BMW, whatever - true sports car. What do I know. I'm 36 and a geezer to the people that buy this stuff.
9. A/F ratio. You don't need it for what you are testing. You won't be changing that at all, and I would not consider anything that did. I used it and it was very helpful in understanding what the #$$&$# MAF was doing (or wasn't doing). It's supposed performance was from changing A/F's at WOT. Of course it was a sham. Live and learn.
You are right on about the computer chip and MAF stuff. I've seen the Aurora run richer and leaner than stock A/F and each time the power went down. The factory setting seems pretty good.
Funny thing - that stupid MAF may have helped a little with the screen removed but the A/F was so wrong the thing was crap. If I ever visit the dyno again, I'll test it again since it has been set back to factor A/F. My hope is + 2 HP from it. I would not be surprised at all if it did nothing or still went down due to an inability to read the air flow correctly.
You just can't beat actually measuring something as opposed to theorizing about it.
I think this is another bogus thing unless you upsized the entire unit. I've looked at a new one out of the box and there is no way around having to pass the exhaust through a certain amount of media to meet emissions. Once you see one and kind of look into/through it, it just seems like they would all have to be the same to meet government regulations. A bigger inlet and outlet may help a little - but that's about it I think.
Also - after seeing how much media the exhaust has to pass through, I realized how insignificant the MAF screen is in comparison.
There are a lot of other factors like the gas flow turbulence and direction when it hits the screen or media, but that converter sure seemed a lot more than the MAF screen.
Any thoughts? I notice the Magnaflow converters really don't even make a HP claim or explain why it's better. Something tells me it's not.
I forgot about the A/F testing question. I agree with Garnes. I wouldn't bother with it. Maybe if the car really isn't making the gains you expect you could consider taking them up on that. But otherwise I would just hook it up and see how it does. It really shouldn't mess the A/F ratio up. Besides, the computer in the car monitors the A/F ratio through the O2 sensor, so it will adjust to get the proper ratio. I think the problem with Garnes' MAF and A/F was the computer had difficulty adjusting because it was getting inaccurate info from the MAF about the air coming in.
I thought most hi-po convertors had a larger chamber in them and therefore more of the cat media. i.e. it was bigger around even if the inlet/outlet were the same. The exhaust would still travel the same length, but there was more capacity for the convertor. I suspect that they don't make huge gains (and I suspect that the convertor is sized to flow at the same rate as the rest of the exhaust piping), and really I'm not inclined to mess with them as they are monitored by the OBD-II, and there are tough penalties for it. I'm no greenie, but I do like that the car is an LEV and I personally wouldn't replace the cat unless the original conked out. A high-flow will also probably increase the amount of engine noise you hear too. Since the Corsa is designed to minimize the cruising note, and everyone here seems to want their car to retain some civility, I would think that would be a reason right there not to mess with the cat. I've heard cars after the cat has been hollowed and it made a very noticeable difference in the amount of sound produced.
Here is an interesting article on SLP's new enhancements for GM cars. Since they are losing the F-body (Camaro SS and Firebird WS-6/Firehawk), they have to find some new markets.
Also of note is the Firehawk treatment of the Pontiac Firebird. This is a car that makes 305 hp already, and the SLP Firehawk bumps it up to 335. This is about a 10% increase (just a bit less) in power. The Firehawk has a much freer exhaust than the standard Firebird, and a cold-air induction like we will never have on the Aurora. I don't think any of us would be willing to go with an exhaust as free as the Firehawk because our Aurora's would be horrible to drive. Although, I suppose you could state that the Firehawk exhaust is similar to the Corsa because they are a similar improvement over differing bases. The regular Firebird exhaust is nowhere near as quiet as the regular Aurora exhaust, so maybe the gains would be similar. Anyway, the breathing for the Aurora will never match the flared, cold-air-gulping nostrils (or placemat sized air filter) of the Firehawk. So, I really think that 20-25 horsepower from the Aurora is probably achievable, but is probably about the limit we should expect.
Even the Regal GS and Grand Prix GTP gains are only about 30 horsepower (the GTX version of the GTP, which just includes the composite hood with ram-air intakes, K&N, and free exhaust only add 20 horsepower. This mod is the closest to what we can do to the Aurora, but still includes a CAI that we could never hope for.), and they include better induction, a freer exhaust, and also a bump in the supercharger's pressure and computer tuning to match it. That is something we don't have an option of on our Aurora's. So if a similarly powered GTP with 240 horsepower is bumped to 270 by a major change to it's induction and exhaust, then I think if we could get 270 horsepower out of a 250 horsepowered Aurora by also freeing the exhaust and hoping to reducing the intake vacuum some, we are doing pretty good.
They have a 225 horsepowered Monte Carlo SS package too. This is a 200 horsepowered engine stock. But, they make internal changes to the engine in the form of higher-lift roller rocker arms to achieve this. It isn't just bolt-on stuff. They also use 160 degree thermostats on all but the Camaro/Firebird (probably because these two cars will actually be warrantied). Personally I don't think the low-temp thermostat is worth the risk to your engine (via degraded oil performance) or the poor performance of the heater in the winter.
I realize that all of these cars are pushrod motors, not high-end breathers like our 4-valve Aurora, and so the gains to their torque curves are more telling than their horsepower gains. Also, the Aurora would probably see more of a peak horsepower gain from a peak-torque gain than the pushrod cars because the Aurora's torque peak is closer in rpm to its power peak. Therefore, supposing the torque gain tapers down gradually, the Aurora would have more of that torque gain still there by its power peak, and thus have more of a power gain. But still, I think a gain of 15-25 horsepower, and maybe around 20-30 lb-ft of torque is about all we should expect from intake and exhaust changes without touching the engine.
don't forget that MAF was deliberately inaccurate. Goofy thing.
You will notice that the gains Corsa advertises are approximately equal for a Viper, Corvette, or the STS. Actually I think the STS is more. Yes, it's all about the stock exhaust on the performance cars being pretty free already. There is a lot to open up on a Caddy.
I'd think the Corsa system is about as free as you can get. After all it's all straight-through. It's 2 1/2 inch. You could make the plumbing bigger, but I'd imagine it's pretty wide open.
The SLP exhaust (for the Firehawk) steps up to a 3" intermediate pipe (from the cat to the muffler) from I believe a 2 1/2". Also, the factory F-body exhaust is somewhat restrictive. It is one pipe back to the cat and then one pipe back to one muffler. And, at 2 1/2" for just one pipe, that would be a bit more bottled up than the Aurora's two 2" pipes especially considering the difference in engine sizes. Total performance from the Camaro/Firebird engine wasn't nearly as important as it was for the Corvette or a Viper. They claim 14 RW horsepower for the Camaro/Firebird system. So figure about 20 horsepower. This is similar to the STS gain, but the STS also makes about the same amount of horsepower (300 vs. 305), not 250. Again, this power gain isn't even 10% (less than 7%, so another 3.5% from intake would give a nice 10% power gain). So with intake and exhaust, I think 10% for an Aurora (275 horsepower total) would be exceptional.
As for the MAF, I hear you. That's why I think Taylor shouldn't bother unless the mods don't make power gains that seem reasonable. That's why you looked at the A/F right? Because the Granetelli MAF wasn't helping the power.
I really feel like if someone can squeeze 270 or even 265 horsepower from their Aurora without ruining the smoothness of the engine, then they have done a good job.
I did A/F's on the MAF from the first run because I knew it was going to change something and I wanted to know what was going on. I also ran it up to 2500 rpm and held it there like in a cruise mode or light acceleration. The A/F seemed normal there - high 14's or so. I think it screws with the computer at WOT only.
Heck the simple K&N gets you to 259. I sure expect an exhaust system to add another 11 - easy. Another mod to the intake - maybe not, but I would not expect a good mod to the intake and another on the exhaust to not factor into the diminishing returns thing. In fact they should compliment each other.
I'm basing the 11 on what Corsa and the other exhaust companies have said/claimed (actually being very conservative based on their claims). So I really think 270 to 275 should not be to much of a stretch. For some reason I think 280 or so would be the limit without engine mods.
Again, only the dyno will give you an idea. I remember reading so many posts about how K&N's really don't do much, but they do. MAF's - oh they are great (I believed it too) but it has not proved out at all.
Come fall, I'll probably want the Corsa and if so, I'll be dying to hit the dyno. So it will be settled. It will be more rough, I'll just have to base the results on old baselines, but a general idea of whether it's +15 or + 10 should be attainable. I did all my baselines in the fall too, so a similar day may help.
I hear what you are saying Garnes. I forgot you got almost 10hp from the K&N. I think 270 is possible too, and maybe 275. Your predictions seem pretty likely. I do think the Shelby gives some indication of the possible torque gain (which points at the horsepower gain since the peak rpm won't change because of a K&N or exhaust), although that engine was probably tuned more for horsepower gains than torque gains. But still, it was tuned. We aren't able tune the cams on our Aurora (at least without spending loads of money). I really look forward to hearing some results from you and Taylor. But I just wanted to say that if you end up with under 270 horsepower, that is still pretty good.
However, I don't intuitively get the complimenting of the exhaust and intake. I can see that they might not diminish since they make independent changes to the engine.
A freer intake means the engine can get more air (and thus more fuel) into the combustion chamber so it can make more power from that. Also, it means there is a reduction in the vacuum some which is less drag (force) on the piston as it moves down. This drag means more of the force the other pistons are creating on their power stroke is being wasted to help the intake piston pull air in, so reducing the drag directs that power to moving the vehicle.
A freer exhaust means lower exhaust pressure in the exhaust pipe. This means that as the piston pushes up on the exhaust stroke, it takes less effort to push the exhaust gasses out the valve and on its way to the tailpipes. When there is more exhaust pressure (resistance) then it takes more power from the other pistons on their power stroke to push this exhaust stroke piston up. Again, if this pressure is reduced, then the piston consumes less of the power the rest of the engine is producing in order to expel the exhaust.
So I can see how these should be independent gains, but I don't see how a freer breathing exhaust can positively help the intake breath in, nor how more intake air, or reduced drag on the intake, can help exhaust to exit the cylinder. Maybe since there is more exhaust in the cylinder from the extra air/fuel then a freer exhaust helps get it out. However, when the piston moves from its low point to its high point, everything in its way will get displaced. It doesn't matter if there was more stuff in its way. Maybe all the extra energy produced by the extra intake charge gets used up trying to push more exhaust out under higher pressure, but that seems unlikely. If that were the case, then it seems like the engine wouldn't make any power at all since the "regular" intake charge's energy would get mostly used up expelling the "regular" amount of exhaust. Maybe the restricted exhaust coupled with more intake charge means that the exhaust stroke happens under much more pressure. The combustion chamber part of the cylinder doesn't really get cleared of exhaust because the piston doesn't move through it (I realize that there is supposed to be some scavanging from well-designed exhaust manifolds). So maybe the higher pressure that part is under, the more actual exhaust is trapped there. That might undermine the efficiency of the intake stroke since there will be more exhaust already filling up the cylinder. I don't know what exactly happens, but the complimenting of intake and exhaust gains has never really made sense to me.
I have to admit I'm not giving this as much thought as you have, but sometimes it is possible to complicate things.
Sometimes it helps to consider the extremes of an example to understand what is happening - or can happen. Consider this - a car is severely restricted on the intake for some reason and the stock exhaust is OK/typical. You put a low restriction exhaust on it. What kind of gains would you expect? Perhaps nothing. At WOT the gas is not so dense and the exhaust push from the cylinder wasn't having a struggle to begin with before the exhaust mod.
One could say - hey, that cat-back does not work, or only added 2 HP. But now you open up the intake and get gains from that. In addition, you test the exhaust mods "before and after" (you spend a lot of time at the dyno) and shazam - that cat-back makes more of a difference now. I think it's possible.
What if the losses in the exhaust push are exponential in some way to the density of the gas? I know it's exponential regarding the velocity, but the air/gas is compressible too and I'd imagine the density plays a big part and friction/energy losses may likely be a function of the density to some exponent greater that 1. That's what's really at the heart of my examples.
Bottom line - you could in theory restrict the intake (I believe) to the point where the exhaust mods (as a percentage even) would add little power. They aren't totally independent and at some point they can compliment each other - positively or negatively. Perhaps this is not always the case.
Without giving this much more thought, perhaps an exhaust improvement could seem "complimented" by intake improvements (easier to get rid of denser air), but the intake would never really "care" if the exhaust was free.
I think you hit it with "Maybe since there is more exhaust in the cylinder from the extra air/fuel then a freer exhaust helps get it out". Just consider any possible exponential function of density.
Now, you have to look at percentages too. That may be the stumbling point. A 4% increase to 270 Hp is "more" than 4% on 250. It's the same percentage though. Depends how you define "more". I'd have to admit it's only "more" if the % is more.
Anyway, that's my simple view. Relationships between two variables like intake and exhaust may not always be steady and constant over all operating points or conditions.
Pre-Test run-I went out and bought a new stock paper filter to test with instead of my used K&N. While looking at things, I decided to test fit the intake kit w/ K&N cone. Sure enough, one of the clamps didn't fit, needs to be 1in longer. Hopped in mom's Z34 to go get one clamp at ACE down the street. Good thing I checked before i'm on somebody else clock. With the intake sitting there, I decided to bolt it in and go for a test drive before I hit the Dyno tomarrow at 9AM. First thing I noticed was how much LOUDER it was when I punched it. It ROARED under WOT. Pretty cool sounding. At first I had my doubts on any noticeable performance gaines. It seemed to perform about the same (only louder) crusing around in my neighborhood. I needed to get out on the highway before I make any conclusions. I don't race around or blast my 800 watt stereo in my sub-division. After my little highway spin, my conclusion is: There is a noticeable difference, there is MORE pull in the higher RPMS and tourque steer is more noticable. This Northstar is pulling like it never has before. Before my car would only barley chirp the tires with the new Dunlop Sport A2's. Now it will burn'em untill the traction controll kicks in like it did with the old Goodyear GA's. There has to be a gain in power! I'll have to wait untill tomarrow for the official #'s. This was only the intake kit, can't wait untill the bored throttle body add's a little more to that too. I didn't want to swap out the TB today, I don't want to do that twice, the intake only took about 10min. Can't wait till tomarrow!!! Gotta go, I'll be keeping everyone posted.
DYNO RESUTS!!! Saturday was the big day for me, tested out RSM racings Intake kit w/K&N cone and bored-out Throttle Body for my 96 Aurora. The guys at the shop were real helpful. It took forever to get out of there, 14 runs and 2.5 hours later, I was done. They only charged me $150 too, should of been $200 @ 80/hr, anyways they were nice guys and let me borrow some tools too.
Alright here's the numbers rated from the wheels. Baseline @ 190.0 HP and ???.? ft-lbsTq (I'll explain later) Intake @ 198.3 HP and 202.9 ft-lbsTq +TB @ 206.7 HP and 214.0 ft-lbsTq
These numbers are from the best run from each set. Unfortunately the #'s for the baseline Tourque were lost???. It took a couple of runs (6 runs) to get that baseline @ 190.0 hp, the screen came up and I saw it and said that I was happy with it (thinking of Garnes Baseline of 189hp) When I was all done at the end, when we went to graph everything, that run was GONE. So I don't have the TQ#'s from my best baseline. Bummer. Next best baseline was 177.5hp and 190.7 ft-lbsTourque. Little low.
Number crunching time: figuring 190hp at the wheels=250hp at the crank, theres a loss of 24% from the 4T80E transmission. I figure that the Intake gain was 8.3 @ wheels making 260.9 hp @ the crank. Total gain was 16.7hp @ wheels making 271.9 HP @ the crank. More than expected, RSM claimed +19HP, I got +21.9HP.
Guys, need some help figuring out the tourque numbers. Figuring off of Garnes baseline of 189hp and 204 ft-lbsTq, he also lost 24% of hp though the tranny. On tourque he lost 21.54% of ft-lbs of tourque from the tranny (assuming 204 ft-lbs Tourque @wheels=260 ft-lbs Tourque @crank). Using those numbers, I lost 1.1Tourque with the Intake and a gain of 11.1Tourque with adding the TB. With those numbers, my final 214.0 ft-lbs of Tourque @ wheels is now 272.75 ft-lbs of tourque @crank. That number might need some adjusting, sounds low to me.
Over all I'm VERY happy with 271.9HP and 272.75ft-lbs of tourque, rounding #'s My Aurora is now a 272Hp & 273 ft-lbs of touque. The car want's just wants to GO FASTER NOW, or is it the driver? The K&N Cone added a little noise when asked to push hard, but no complaints here. I think this was a great gain for opening up the intake and forcing more air with a bored Throttle body, a gain of 22HP dyno tested is great. Can't wait till fall to throw on Corsa's exhaust, probably go dyno one last time for gaines on that too. Then I'll be done. I'm happy.
Garnes what were the dyno #'s from the Vette? All these test were with the bottom part of the airbox on and the hood open. Couldn't get bottom part out because one of the screws was facing up, meaning it was screwed in from under the car. How did you get yours out? Should I take it out?
Don't get hung up on the numbers! Just look at the change. May baselines were 189 HP one day and 191/2 on another. The results with the K&N and box were correspondingly 2 or 3 better on the day of the better baseline. The K&N and airbox mod did maybe .5 HP better and 1 ft-lb better on the first day than the second - whatever. Pretty darn consistent.
Just forget the 170-something HP run, something was not right. It could be the equipment and such. That's way off.
Your torque numbers seem a little low - for just the intake, but again, don't worry about actual numbers. Just look at trends and changes. That's all that matters. If the dyno and the computer equipment/program/whatever is reporting a true 200 ft-lbs as 190 or 195 - who cares. As long as there is repeatability and consistency, you can measure change and that's all that matters.
My thoughts - the intake mod may help at the very highest rpms the most and thus peak HP. I got a best improvement of +7 peak HP and +4 torque from the K&N filter. The K&N helps more in the 5000+ (peak HP range) than it does at 4400 (peak torque area). Now, the air box mod added no peak HP but added some HP going up. It helped peak torque though because this change improved flow in the 4000's but not the 5000's.
Your TB results are pretty impressive. Lots of HP and torque. Was that TB done a couple times with similar results? Same with the intake - was that just one run?
I agree with your 272 engine HP estimate, but the torque is probably higher. Here's why. I'm assuming your intake added + 5 peak torque. I got a little more than that just with a K&N and my air box mod, so +5 should be a safe assumption - especially since the HP numbers are there and are pretty consistent with my results. So, that puts the baseline torque at about 198. You finished with 214 - an increase of 16. Yes, the "loss" is very slightly different for torque than HP (my thoughts on that below) and it seems to be about .785. Therefore 16 lb-ft/.785 = 20. 260 + 20 = 280 lb-ft. I just find it hard to believe that the intake added no peak torque let alone LOSE torque. You had to gain something and +5 is an easy bet - heck, I got 5.5 to 7 peak torque.
I think the reason the "loss" on HP and torque are just a smidge different (barely worth noting really) is that perhaps the losses with the automatic transmission are indeed just a smidge different at 4400 rpm than they are at 5600 rpm. That's just a guess. I've used about .766 for HP and .785 for the torque based on the observed "losses".
Corvette numbers - I saw a dyno of the 2000 or 2001 vette on "crank and chrome" - I think it's now "two guys garage" or something like that. The vette is rated for 350 HP. The baseline was 265 HP I think. 265/350 = .757. The same as I got even though they are different drivelines and all. I can't remeber torque. It was on their web site too (which probably has changed). The K&N cold air intake added +22 HP for them at the wheels on that vette.
Air box bottom. Yes, get that off of there! With the hood up, it probably didn't hurt you, but with the hood down while driving I think it will. Removing the bottom of the box will expose a large opening below where a lot more air from behind the fender can flow to the cone. Mine had a bolt that held one end in. It is easily removed with a ratchet. The other side was really just held with a post (of sorts) that fits very tightly against the rubber sleeve on the air box. This is hard to describe, but there is nothing to remove with this other point - you just MUSCLE it out. Pull up and wiggle it. It will pop out. I hope that's what you have. I can see how this might look like it's screwed from the bottom.
Give me your e-mail or something. I'd like to find out more from you about the throttle body work. I used to live near you and drive up to the Chicago suburbs from time to time.
Comments
Anyway, this might mean I'll have some time to baseline the car. I am considering the new GTech Competition meter. I've posted on the Cadillac Performance page at GMForums about it. It seems pretty neat. I'll just have to find some space where I can try it out. There's a closed-up Wal-Mart near me that has a huge empty parking lot. Perhaps I'll check that out...
Actually, there is one performance upgrade you can do that costs about $2,000 and can be installed with just a pencil. You just check the box labeled "4.0" on the order sheet...
By the way, I'm not using the 2 1/2" vacuum hose anymore. Garnes crunched some numbers, and it will definitely be too narrow. I will try to squeeze the 4" dryer hose in if I can, and if not I will just stick with the K&N and a stock setup. I have to wait for that trim removal tool to arrive, though. I'll keep you all posted (I'm sure you're on the edge of your seats)...
Also, any idea on the cost? Figure both components and labor.
1) Struts -- I put KYB GR2's on the front of my 95. Firmed it up nicely. Highly recommended. Cost about $120/ea if you can do it yourself.
2) Sway Bar -- Someone on here (Henry?) found that the Caddy STS front sway (anti-roll) bar is a direct bolt-in replacement for the Classic's front sway bar. Probably makes a great deal of difference. Price would depend on whether you get it from your dealer or a salvage yard.
As for the sway bar thing, this is a copy of the old post with part #'s.
HENRY- I note in your posting of 27 Jan, #269 that you have installed
Caddie sway bars (plural) in your Aurora. I knew that a 2000 Seville rear sway bar is a direct bolt in (GM part # 25666234) and that gets you a 22 mm rear bar. My 96 Aurora came stock with a 17mm rear and a 27mm front. I have already installed the 22 mm rear bar. Is there a front Seville sway bar that will fit? I know I can put in a 98-99 Aurora bar which is 29 mm but if I'm going to do it I might put in bigger if something is available. Thanks in advance for your info. To other readers: I also put in polyurathane end links and center bushings on my sway bars F & R and you could tell an immediate difference. Also KYB struts up front. Would recommend both the struts and bushings to anyone who wants to tighten up his classic Aurora.
When I asked about the shocks, I also asked about the sway bars. They had no info on the 99Aurora swap and wouldn't comment on using Caddy parts on my Olds. I didn't look to far into it, no measuring of anything but I most likely delt with a lazy Service/Parts guy.
It probably can be done. I wasn't happly concluded with my search on the sway bar thing, so I went a different way, an alternative. I bought RSM racings Front Strut Tower Bar http://webhome.idirect.com/%7Ersm1/aurstb.jpg (the black box on top of the bar is only on early 95's,btw). I Installed it 2 weeks ago and noticed the improved tightness in the first turn. It makes the Aurora want to carve into those turns, not "roll". The front end stays parellel to the road more than ever. Deffinently tightened up this classics body roll. My girlfriend noticed a difference too. Now she wants one for her 96 Accord. I think it was well worth the $289 to firm up the ride, I would pay the $199 for RSM's rear bar too http://webhome.idirect.com/%7Ersm1/aurrstb.jpg, if I could get it too fit into my trunk around my Custom 800 watt system taking up half the trunk. The ride would be even tighter then. I think it would fit infront of my false wall in my trunk, but I have to take the wall down any time I want to work/tune my system so I'd have to take the strut bar down evertime too. Oh, well. I thought about it and decided not too, I value what little trunk space I have left, from an already small tunk in the first place.
I recommend www.rsmracings.com front strut bar. They also sell there own bushings and mounts for a couple of places, might look into that too. They have more available, than whats listed.
800wattAURORA.
Anyone (especially if you have a new Aurora) that is interested in the Corsa exhaust, you should call Corsa first. (I know, everyone says talk to Jim Browning, but I just said I had questions and figured I'd talk to whoever got the call. I bet they are all pretty knowledgable people, and we'd never know what the rest of the team is like if we all talk to Jim
What he said was the Caddy system would fit the new Aurora with some slight adjustments, but that the tonal quality probably wouldn't be the best. Because they tune their exhaust specifically for an engine, the Northstar wouldn't be ideal for the Aurora. He said you would get the performance (it's still open and straight-through), but they wouldn't be happy with the quiet. He said they tune it for a quieter cruise than stock. Basically, all the sound should come out the back with no resonance inside. When you open her up, then there is enough sound out the back that you can hear it inside, but at cruise it should be quiet.
They may or may not go with the tips they use on the Caddy. He said they have another possibility in the works (he said it was something they tried with the C5...). Not sure if it's tips they actually use on the C5, though. They have couple different ones. Maybe those mega tips from their titanium mufflers... I think that would look a bit garish on an Aurora though.
Garnes, I wonder if you noticed some cruise note because the Cadillac has a bigger engine. I wonder if there is a cruise note anyway with the stock setup. I've yet to drive in a stock Seville. But the engine is noticeably bigger. If you'd ever been in an 80's Camaro with a 305 and then one with the 350, the exhausts are basically the same, but the 350 definitely sounds bigger. It's possible the Northstar has some cruising sounds that we don't get with the Aurora. Paul really stressed that the Corsa should be as quiet or quieter at cruise. Maybe the Corsa cruise note is actually quieter in terms of decibels, but is a more distinct sound so you can more easily distinguish it from other road and wind noises... I'm just speculating and opining here, so take with a (large) grain of salt.
However, I fully expect the exhaust they develop for the Aurora to be perfectly liveable at cruise, and I fully expect to buy one as soon as they finish it. In fact, I was calling to get a few questions answered, and then I was going to order the Caddy system. Their exhaust is made to be clamped and self-installed. This is great as I have had poor luck with any exhaust shops around me. I did a few changes to the 'vette, and each place I went was less than perfect. No horrible disasters, but I was never completely satisfied. They'd either cut up some pipe I didn't want them to, or ruin the piece they were taking off, or try to snow-job me into getting other replacement parts that I knew I didn't need. So, if I can do it myself I will be quite happy. Plus, it means the stock system can be put back on for whatever reason.
From what you said, it's definitely worth waiting for something tuned for the 4.0. I'd guess the same as you - it's for the new 4.0, but it should be workable for a classic. However - Jim Browning told me they have put a system on a classic. If they "digitized" it as they made it, then they have the information computerized so that more can be made. Of course they have put one on the new 4.0 as well now.
As for quiet cruise - well they key is at what speed. 60 mph - yeah I think they are probably right about no noise. Over 70 and the rpms start to climb a little with the 3.71. Things change. Again, the STS I drove in when I visited (Jim Browning Sr.'s) car had a little note in the car at 70 to 75. It was slight. You had to be listening for it like I was, but it was not intrusive. Going up an overpass and yes - it got louder at 70+ Going down and it's gone. Flat surface - very slight note.
If you want to fly 80+ I'd expect more of a note in the car.
Yes, I agree, the 4.0's smaller size should make for at least a slightly quieter exhaust system than the 4.6. The Aurora is certainly every bit as sound proof as a Seville so I'd expect it to be quieter.
Yep - anything that has gone on an Aurora thus far has been a Caddy system.
Doing something for an Olds - this really doesn't surprise me. I will not be surprised if they do this for the classic either. The new Aurora is a no-brainer. It supposedly is about the same as the current STS, so the plumbing is practically already designed. Any muffles and resonator developed will automatically have you a new Aurora system. You should have one for sure.
About the classic - they made these things for 5 years. I'd guess there are over 125,000 originally out there. Perhaps 150k. That's not too bad, but certainly not a lot.
However, here is the key - It's a "cool" looking car with an unbelievably wide range of appeal. The new Aurora is nice too (I personally like the front better and the chiseled bulging sides are just about as tough as the classic, maybe better depending on your opinion - the back - well it gets a C - the rest is an A). The classics can be had for a very reasonable price now given their age and mileage. A lot of younger people are scooping these up now too because it's just a cool car and are interested in opening up some of that V8 potential. I think a lot of the classics are going from 50 something first owners to 20 or 30 something second and third owners.
Oh - and they tend to be well taken care of and not abused either.
So, there may be a market out there and they already have the groundwork on the 4.6. That's my theory at least.
I think it's a done deal. I'm buying this if/when it comes out next spring whether I have to modify the new Aurora system with a custom visit to Corsa or not.
I would think if the Corsa mufflers are optimal for both then there would definitely be no reason not to offer a system for both. All that would take is a little pipe bending.
I wasn't all that keen on the rear styling of the Aurora at first either. It has grown on me now, and it is distinctive if nothing else. However, it does seem like they tried to keep some heritage there by sloping it like the classic, but it doesn't work nearly as well on the more edgy shape of the new car. It definitely looks better on the smooth flowing line of the classic. The only classic design that I would do a little different is that strech of "lights" that runs across the trunk to look like the taillights run all the way across. That's the only part of the design that's dated to me. It says "early 90's" while the rest of the car is a more timeless sleek design. The hood can look a little long from some angles, but I think if they shortened it, it would look dumb. Oh, I also prefer full-framed doors because otherwise the glass always feels like it's getting bent or something when closing the doors. The classic definitely has a cool look, though. It's a luxury performance car, and it's look totally says luxury and performance.
A couple of things kept me in the Classic arena. I like the styling of the new Aurora, yet it is not as distinctive as the classic. It sort of blends with the Lincoln LS and a few other current models.
To me, the feel of the classic is more solid, the build feels more robust. I know they say the interior and cargo space is nearly the same, but the new Aurora feels smaller inside, more cramped when passengers are on board.
But the deal breaker is the price. Even with rebates and dealer discounts, a loaded 4.0 is nearly double the price of a 99 Classic in exceptional condition with under 30k miles.
As for fogies, I tend to agree that 1st owners of classics may have been past their mid life crisis. And they didn't buy the car to power around the back roads or challenge BMW's on the interstate. Rather they purchased a refined top of the line American car. Advanced with it's head turning style, luxury, technology, and all those cool buttons and switches that turn the cockpit into a visual experience at night.
2nd owners may be younger with less purchasing power and savvy enough to see the incredible amount of car that can be had for the dollar. Plus, a little younger often means a little more willing to take risks. The Classic's have a risky image, thus the reason most used car buyers seem to avoid them. I've been lucky with my used 95 so far, but have to admit that the slightest stumble or a sound I don't think I ever heard before scares the heck out of me.
The horror stories posted on these boards don't help the image, nor my comfort level. I want to believe that since my 95 was a one owner, traded in at the original selling dealer by an over 60 fogies makes it a safer bet.
And I sometimes "hope" that the mechanical failures I read about just might be influenced by a driving style enjoyed by the younger riskier 2nd and 3rd owners.
I have on my 1999 Onyx Black Aurora a set of 18 inch Lexani Roma, all chrome wheels with Nitto eXtreme tires size 235/40/ZR18.
I also found these website. Click HERE were you can load any Olds Vehicle and see what it would look like with some custom wheels.
See how an Aurora would look, you can change the color to match your own, you can even drop the Aurora several inches.
Make sure you click on the far upper right hand side of the screen were it says "View Wheels on Vehicle" and a new page will load and check it out.
aurora402002@yahoo.com
Actually, if anyone has some pics of their Aurora, I'll put 'em up for you.
Henri, I don't think you can post pictures on the Edmunds board unless you have it on another web server. Most free servers, like geocities, don't let you host pictures for display on other sites. So I can't display the pictures here unless I were to spend money for a server (or for a static IP so I could have my own server, dang DSL).
I'm sure plenty of Classic Auroras graced the parking lot at the post office first thing in the morning - and the bank.
It's true, I still see a lot of really old people tooling around in the Aurora. It's cool really.
I like the tail of the classic. It's clean and pulls the whole thing together in the back - very few cars look as clean from the back. Generally, it's the more lines, shapes, and colors, the better. Each year it gets more grotesque. Now we see the goofy after-market looking tail lights coming from the factory. Ug.
However, I'd trade for the front of the new Aurora any day. The classic front end is so bland from a dead on view. Those air vents/grills/whatever on both sides do it on the new one.
Oh - to keep this topic legal - Jim Browning e-mailed me that the Corsa system will be for the new Aurora. If I have to wait until next spring to find out they won't custom fit it to the classic until the following fall - well that blows. I'll try to find out more.
I'm going crazy - all weekend someone or several people were driving by the cross street a few houses down with the sweetest exhaust systems. Not loud, but really nice. It was like smelling a T-bone on your neighbor's grill when you are really hungry (my neighbor does that too me all the time).
Another interesting note - the mufflers will be the same as the Seville. The resonator is what is "tuned". Paul said the resonator is what controls much of the sound.
RJS (or anybody else) - please add anything you know about the differences in the valving on the two 4.0's. It's pretty interesting how these engines have very different personalities. I'll bet the new Aurora stock exhaust sounds different than the classic too.
Duration @ 0.150mmlift (not .050") 242 degrees intake, 236 degrees exhaust, 1.98 degrees overlap
Lift is 6.15mm (.2421") intake, 5.94mm (.2339") exhaust. The rockers are 1.68:1, so that gives the actual valve lift. The valve sizes are listed in the camshaft specs as 10.5mm intake and 10mm exhaust. However, this seems impossibly small once I thought about it. That's less than 1/2" wide. Under the valve specs, there is an entry for exhaust head diameter which is 27.880-28.140mm and the intake head diameter is 34.090-34.350mm. This seems more reasonable for the valve sizes.
Supposedly that's a bigger intake and smaller exhaust than on the classic. The bigger intake should improve breathing at higher rpms, and the smaller exhaust valve will speed up the exhaust flow (since the same amount has to get out a smaller hole in the same amount of time). I believe this is better at lower rpm, and was done more for clean running than performance. However, I'm not sure. Plus, without knowing the cam timing, this is only one part of the equation.
This statement about the redesign of the Northstar might help since they both got the same redesign:
Revised combustion chambers are superior to previous designs in terms of both tumble motion of the incoming fuel-air mixture and burn rate. The intake and exhaust valves have been resized. Larger intake valves improve the engine’s breathing ability, while smaller exhaust valves increase flow velocity, an aid to catalyst light off.
The Olds site doesn't go into this much detail about the redesign, but I really think the same things were done to both.
Taylor,
The system that we have done is for the newer Aurora's. The same basic system that we build for the STS also fits in the newer Aurora's. We did not have to do any new tuning of mufflers for this car at all. Just the tubing lengths had to be changed to make it fit.
We have built one system for a 98 Aurora. It sounds very similar to the STS. At this time, we do not have plans for building a system for the older cars, just not enough demand.
Some people have talked about buying an STS system and having a muffler shop fit the system to the car. It will require some new pipes to be bent to make the system fit.
We do not have time to custom build any more of these right now. Maybe in the fall.
Thanks,
Jim
Well, what to do now? Time to go and get some custom bent exhaust estimates.
Still want that Corsa sound though. Hum.
800wattAurora
If I do this, I'll make the trip. Take note here - when I was considering this before, Corsa said that while I would be there, they may be able to knock out 2 systems if anybody else wanted one. So, this fall, maybe one of us can go and get both made. Just a thought.
ALSO - I don't want to tick anybody off a Corsa so I'm not going to start hassling them about it, but RJS and I have both talked to Paul Santiago at Corsa and he specifically said the new Aurora did not sound as good as the classic with the Seville system. Therefore, Paul said they will make a resonator specifically for the new Aurora. I guess it has to do with the fact that the exhaust valves on the new 4.0 are smaller and this changes the sound. Whatever. I don't know why there are two different stories from Paul and Jim.
Paul also said the Seville system sounded great on the classic and confirmed that nothing is in the works for the classic unless you had it custom fitted.
Any luck with the dyno and your other projects?
If you buy the stuff now and have a local shop hook it up, make sure they use good equipment. The system should use mandrel bending or some other type that doesn't restrict the flow. Those ripply bends narrow the pipe at the bend and cause a constriction.
Spend $1,000 on the product and $250 for the "professional" labor?
First time I used a "polymer wax" made out of Teflon. IT"S. GREAT. I used to use Meguires religiously, never again. This wax is the best I've ever used. Nothing sticks to the car any more. It's rained 3 times on the finish and still no water spots and still shines brightly. Water doesn't bead-up, it just sheets right off. Someone asked me yesterday If a garaged my car because it looked so clean right after it rained. I don't, I said good wax. Find some Teflon compounded wax and you'll never go back. I'll post back with the name of it, I've never heard of it before. It was sent to me by my old neighbors who moved to La Quenta, CA (outside of Palm Springs). Marty uses it on his white LS 400 and the wives blue BMW Z3. He said everybody out there use's this stuff because it's the BEST. Any ways, enough about the wax already.
First, I realy needed some new tires a couple of weeks ago. So I did some thinking, do I like my stock alloy rims? Debating on some custom 17-18's or keeping the dull stockers. After looking at the pros/cons of up-sizing rims and the cost of low pro tires and keeping it looking like a Luxury car. I decided to call AAArims and chrome rim exchange my dull stockers. The chromes looks SO much better. I've always liked the classic's chrome rims, even before I got my car. The rims arived 2-3days later in A+ condition, only two knicks that weren't taken out before they chromed them. I have no complaints at all, they look great, especially for $650. Ended up going with Dunlop Sport A2s for tires. So far about 400miles on them and they are also GREAT. Way better then the old worn out Eagle GA's. The Dunlop's have a traction rating of AA and tread of 420. Got them at JustTires for $560 with Alignment and road hazard pkg. Free replacement and alignments if problems and Free Tire Rotations for these 50K waranted Tires, through them.
Before when I was thinking about what rims and tires to buy, I thought about my suspension. If I throw some struts on before the tires, I could do it all on one alignment. So that's what I did. Found a set of KYB G2's for $62 each plus two new KYB boots for $10ea at HTTP://WWW.PHILSINC.COM. (Cheaper than tirerack's $70ea) Phil's happen to be in the burbs of Chicago too, thats where I live, so I went and picked them up too. Ended up getting the KYB's put on for $40ea at a Midas that my buddy works at and then drove it strait to JustTires for the Sport A2s and the new chromes and an alignment.
So, now the Aurora is riding and styling better than before. I also recomend the Strut tower bars from RSM. The ride is nice and tight now. As for the RSM Intake and TB, I unfortuneitly can't work out a convient Dyno time with my long hours at work. Probably going to split a new G-tech Comptiton or ap-22 meter with my buddy John who has a 94 Mark VIII, 75 Corvette 350, and 69 Camaro SS 350. His father has a 99 STS that we'll test that out too, along with my Mothers 99 Monte Z34. Seems to be the best bang for my/our buck. The two dyno places were also booked for 3-4weeks and cost around $220-250 for 2 hours. So i'll be ording one of those performance meters this week, but Which one?
Feed back everyone!!! AP-22 or new Gtech?
I figure the the best time for me to get a good baseline is before I need to arrive at work at 6am. Found a Frontage road entrance to a highway 2 minutes from my house. It's a nice strech of road thats flat, long and empty a 5:15 AM and with no places for cops to hide. Might end up testing out the Intake kit and Ported Throttle Body in 0-60 times only on the day of install. No good/safe places to 1/4mi in Chicago going 0-90+ multiple times testing each piece with numerous runs. But that next morning I'll be out there 1/4miling untill I'm blue in the face.
Garnes, count me "IN" on the CORSA tag-team exhaust install in the Fall. SERIOUSLY!!!
Let's try to set a date with Corsa in a couple of weeks. It would be cool to finally meet you, or anyother fellow Aurorians that post here. Time will fly-by while we shoot-the-bull in the waiting room for our custom install's at CORSA. Where do you live? We can compare our mods and you can test listen my 800watt system that I love to talk about. I've also been looking at a possible ram-air set-up location. More about that later.
800wattAURORA
Anyway, I agree with Henry about having Corsa custom fit it. Jim also said we will have to wait until fall when they slow down. I'm not sure any date can be set now. Hopefully by October/November they can do this. That's really not long at all.
Dyno - you could just make your improvements - all of them and then do one dyno. It should give you a general idea of what is happening. My baslines were 189 to 192 HP at the wheels for a stock car with a clean paper filter. I even have the atmospheric conditions for those days too I think. As long as the car is well taken care of, I think the car should perform pretty consistently with 20k miles or 80+k miles. I'm also assuming you'd be dyno testing on the same/similar equipment under the same SAE standards.
I would probably dyno the Corsa too just for the fun of it, so that would give you more information to deduce the increase from any other improvements you have made.
With the Corsa and a simple K&N I expect the 4.0 to make at least 270 HP, and 275 may be more likely - maybe even a little more. With the throttle body and improvements to the intake, I think the engine could produce 280+ HP. That's probably all it's going to do without major money thrown at internal engine improvements. Quite frankly, that would be plenty of power to keep a smile on my face all the time. I'm pretty happy now with just some intakes mods and a K&N. The darn thing moves really well as is.
I think there are definitely limits to what you can gain with bolt-ons too. If you could get 275 hp out of it, you'd be doing great. Really, that's like the SLS or ESC except with less weight and better gearing. The Shelby Series 1 only makes 320 hp and that thing is cammed like crazy. It doesn't make that power until 6500 rpms. It doesn't have intake or exhaust restrictions for a quiet ride, and it also has internal improvements like the camming. In fact, Shelby was hoping for a bit more power from it. Although, for a 4.0 liter engine that still needs to make low-end power in a street car, that's pretty good. It also only gains 30 lb-ft and it too is at a higher rpm (5000 rpm). Since the Aurora isn't going to make power at 6500 rpms, the torque gain is the most telling. So I would think that without any internal changes, gaining 30 lb-ft would be a great achievement, and perhaps a little overly ambitious. Even if you gained 30 lb-ft at the torque peak, and say 25 lb-ft at 5600 rpm, that would be a gain of about 27 hp @5600 giving you 277 total horsepower. I have to say, I can't picture getting this much or more with just some bolt-ons. You really have to take most claims with a grain of salt. That is just my opinion, though. But I think you could gain enough power that the bolt-ons are worth it. If ultimate horsepower is your goal, though, you need to open the engine up.
I also think there is some diminishing return. Like adding the K&N frees up the breathing. Cutting the screen off the MAF might a little too, and so might a bigger throttle body. Suppose any one of them frees up 10hp, then I don't think all three would free up 30. I think all three might do 15 or so. The engine only needs so much air. Supposing the stock airbox provides 90% of that, then there is only room to gain 10%. If each individual mod can gain 8%, they won't gain 24% together. I'm making this stuff up, but my feeling is that there is only so much to be gained. I think as you free up the intake and exhaust, the amount you can improve with the next bolt-on is diminished. Now, if you can get cooler air in, then that is a bit different because you are putting denser air in. The exhaust diminishes too in my opinion. There is only so much more power the car would make if it had open headers. Lets say it could free up 15 horsepower. Suppose the Corsa or a high-flow cat gets you an extra 10, then adding the other would probably just add 2-3. Anyway, that's just my opinion. Just to be clear, I totally made up the numbers in this paragraph. They aren't based on anything at all.
Rjs-Thanks for your vote for the G-tech Comp. I always read the caddy forms after I checked out the Aurora boards. So I catch most of your posts, thats were I first heard of the new G-tech. Sounds like it will be the breakthrough for Performance meters, if I actual can do everything they claim it can do with precision accuracy and be repeatable. Anyways, I think that my buddy and I will split it and test it out for fun, I'll come up with some ram-air&heatshields that I can test out.
Next topic, that -Tbadra- guy has some interesting ideas, huh? That was pretty funny on the -Performance for STS???- topic. What do you think about some of his ideas? They don't all sound bad, but his performance claims are outragously high. Some of them don't apply to the GM Northstar V8 motor like they would to most all GM V6's 90blocks (he ASSumes wrong). Where's the time slip that he just ran? Counting chickens, ha-ha.
Garnes-I wasn't aware that you ment they would make 2 exhaust and ship 1. Personally I want CORSA to do my install, I don't want the customized kit for $1000+ and have Midas put it on. I'll enjoy the road trip with my Girl. We should DEFINATEILY meet up in the fall for the install, let's give them till August 1st and try to set something up.
Dyno&More-I found A place 5-blocks from my work that customizes Imports, http://www.apgperformance.com they had a sign outside for 2 dyno runs for $50. So I went in and talked to them. The parking lot was fully riced out, my Aurora was the only American car and V8 in the lot. There was one car I would trade in the Aurora for though, A NICE Flaming Orange Toyota Supra Twin Turbo fully riced-up, Supra's are the caddys of ricing . Anyways, waiting for my turn in line, the guy infront of me was interested in a chip for his 94 Integra. Any mods he asked? Intake, Exhaust, Piston&;Cams, Polished Type R intake Manifold, Crank shaft., Air fuel something and something else. He wanted to know the performance gains with his V-tech, He asked whats the rev-limiter? 8700RPMS Now!!! Could go up too 9800rpms if he wanted or NO-limit, SUCIDE SHIFT. (Thats Insane) Anyways the guy said we can have one in 2 days programed with his mods and he could go and hook-it-up test drive it before he bought it. Good Customer service, drive it before you buy it. It was a very interesting conversion. Next in line, My turn, The 50$ for 2 runs is for a Baseline and a re-confirming run. Dyno tuning is $80per hour. So I said Sold. 2 HOURS PLEASE. When, He said tomarrow? I Have plans this weekend so I Got next Saturday July 6. I also haven't gotten the right tools for the job yet. You need a star key set to take off the Throttle Body and I don't have my own Torque wrench. I Looked at Star Sets yesterday at PepBoys, slim selection, but I bought a 16pc set T10-T65. Only the T20 fits one of the bolts. I need one between T45-T50. That pissed me off. I'm going to return it and just by the T20 and the T47 that they only sold seperatly. PepBoys rents tools too, they wanted $60 for the tourque wrench, I'll buy a good one for a little over $100. I have one at work, but I can't borrow it because we only have 1 and the night shift might need it. So I also asked APG if I could use one of their Tourque wrenches while I was there, the guy said SURE no problem. You can use what ever tools we've got. Call me next week for the time and directions to our other building.
So I guess I should put in clean paper filter, since I have K&N panel for a STOCK baseline, right? My K&N has over 9,000 miles on it, I've cleaned it a couple of times but never re-oiled yet. I think I'll test with hood open on all runs. They also Said they could do Air/Fuel ratios too for more $$$. Is it worth it? I didn't ask how much. First test baseline, than RSMracings Intake kit w/ K&N Cone, than add the ported 80mm Throttle Body for the total gain. Don't think I'll test just the TB vs. Stock. Hopefully I can get this done in 2-hours. I asked my father to come and watch/help, he said sure, I'll supervise and make sure you don't srew anything up on that fancy car of yours (he drives a 97Escort wagon,doesn't care that he drives a grocery getter) And I'll even hand you the tools and read the manual out to you son. What a guy.
I figure that Total gain should be around the claimed +19hp for Intake & TB. That sounds about right for V8's that have been opend up comparing it to 5.0's & 5.7's. The exhaust should help compliment the intake for a few more hp, probably between 10-18hp, I might as well go back for one more dyno for my cars current/finale horsepower. I'll most like build a heat-shield and ram air device to help achieve that amount of Air that I it got with the open hood dyno. No gaines really expected, more efficency.
The nice Corsa chrome tips will give me a nice slighlty midified look and have a great sound coming from them too. In the end I'll be happy with any noticeable gain and the good looking/sounding exhaust. I want to go for a run at the track when it's all done in the fall just for the hell of it.
I don't think it's going to turn into a rocket when I leave or anything, I just want to add a little more umph to it. The 250HP is nice now but a more=faster. The hopeful 270-280+hp when I'm all done with these mods plus a Corsa exhaust in the fall will make me smile even wider everday when I drive my baby.
This 96 Classic will be my FIRST time drivng down the drag and making dyno runs. This is my first car that I've ever fully paid for, modified performance wise, and invested $1000's in stereo equipment. Hopefully I will own many nice/fast cars in my life and be able to afford to due whatever I want to them. Well you guys know my plans for my first documented modifing.
Wish me luck.
800wattAURORA
taylorsurf@attbi.com
Talk to GTech before you buy it so you know what you are getting into. It will be a cool product, but as of right now they are still making changes. If you buy it now, you'd be a beta tester. There's nothing wrong with that, but you should know what you'll be getting.
You said you have cleaned your K&N many times? I assume you just mean knocking crud out of it. If you've rinsed it off or used the cleaning spray you have to re-oil it or it won't filter anything (except maybe rocks, matchbox cars, and other large objects). Also, it doesn't need to be cleaned very often. If you are just clapping it out, no biggie. If you are hosing it off and such, you might be shortening it's life expectancy by cleaning it every few thousand miles.
As far as those bolt-on gee-whiz electronic gizmos, I've done most of those to my Corvette and the most noticeable difference they made was in making the car run less smoothly. The custom MAF and custom chip just made the engine quirky and prone to knock in hot weather. Underdrive pulleys killed the alternator's ability to keep up while idling. If you had the defroster and headlights on, the car would practically stall when stopped because of the low voltage. Low-resistance wires and a high-output coil didn't make any noticeable difference except in radio performance. The 160 degree thermostat made the heater almost worthless in the winter, and it does hurt oil life. If that GMForums person thinks water isn't a product of hydrogen rich fuel and oxygen rich air, then I think they just don't want to see it. I assure you that water gets in your oil from the combustion process and that if the oil doesn't get hot enough it won't burn it off. That's why short trips can shorten the oil life. It's because the oil doesn't ever heat up to it's proper temperature.
It's funny you mentioned TBadra. I was of the impression it was a chick, not a dude. I was most amused by her "science and logic" argument that amounted to saying the engine is :
-spark
-air/fuel
-compression
-computer
and that was it. That is neither scientific, logical, nor even an argument. It's just a list of words. She didn't expand on it or explain it in any way. It was basically at that point that I figured I couldn't win. I can't argue with someone who doesn't make logical arguments. Of course you can't tell someone they aren't making an argument, or that their argument isn't logical. They obviously think it is or they wouldn't have offered it in the first place. And there is no point in creating conflict on these boards.
Really what I have a problem with is the idea that there is essentially free power in an engine. Like in the years spent developing a new engine, none of the engineers thought of trying these simple power-building techniques. While there is usually power to be made, it usually also has a trade-off. If someone can point out the tradeoff the engineers made to compromise performance for some other reason, then it's much easier to see how you can gain that power back. It's easy to see that the Aurora had to be real quiet, and if you don't mind a little more exhaust noise or intake noise, you can improve the flow through the engine. That makes sense to me. However, when some product (like a computer chip) claims to make 20-30 more horsepower with no downside, that's hard to swallow. The powertrain engineers have a much more intimate knowledge of the engine, and they spend about a year developing the programming. Some chip company probably spends about a month. It might make more power, but if it does, it is almost certainly because it allows more knock, requires a higher grade fuel, or just worsens the drivability. The thing with the thermostat was pretty absurd. If all that matters is the engine is cool, then why use a thermostat at all? Let the engine run at 100-120 degrees and see what happens... There is a reason cars come with 195 degree thermostats, and there is definitely some trade-off to a lower temp one. If you are aware of the trade-off, and think it is worth it, then fine. But there isn't too much free power out there...
1. Cleaned but have not re-oiled the K&N. HOLD ON HERE. I hope you mean that you just brushed it off a little and knocked the bugs out. If you applied the K&N cleaner and literally washed the dirt and oil from the filter, but have not re-oiled the filter, the filter IS NOT filtering much any more. It has to be oiled with K&N oil as per their directions. If it's not oiled, you are hurting the engine. Dirt is getting in there. The oil is what makes the dirt stick.
2. Your dyno plans seem good to me. Yes, get a clean paper filter for baseline. It is a must. Paper filters block off pretty quick compared to a K&N type, so a slightly dirty one will probably lower the baseline. You might be surprised how long it takes to get out of there.
3. Corsa. Last year, they did not have time for me to visit until well into fall. I'm not to sure about August 1. That may be early. Jim told me "fall" again this year. I agree about having Corsa do the work. But, if you go, I may sponge off of your visit, however I may just visit myself as well and meet you there. I really would want them doing the custom work as well. It's good that they have done one other classic now so they know the bugs. I'd also recommend having them "cut-up" the stock system so you could put it back on if you sell it or whatever.
4. Gains - I have to agree with RJS about diminishing returns - especially with improvements made on the same end (all intake). To illustrate, just consider this - you could remove the entire air box and filter and intake tube (assuming you could still hook up the temp sensor somehow) and dyno it. Just run it with the MAF and TB naked. You would get a certain gain. This gain will be less than the reported gain of each individual improvement added separately. With the stock intake being restricted, any one improvement will be greatly appreciated by the engine, but the second one will add less, and so on. It can only make use of so much air - especially with stock exhaust.
Don't get me wrong though - I expect the TB and intake to certainly better than just one. I'd think the intake makes the biggest difference. I think 270 is easy to get with the exhaust and intake, but perhaps 280/low 280's is about the limit no matter what else you do. Again, this is just opinion. You never know. Also, consider this - the 71k Mercedes S430 does about 275 HP/295 torque. It weighs over 4100 lbs too. A slightly modified Aurora is on par with this engine performance, but of course with a totally different character for sure.
5. I HIGHLY recommend using Mobile 1 or at the very least some new oil before hitting the dyno. You are running it hard on there. The M1 may help everything run better. There is a difference between M1 and conventional oil at those extremes. Also M1 has better performance than other synthetics except for maybe AMSOIL. A new oil filter will ensure the best oil flow and pressure too. Use a good 93 gas as well.
6. Don't forget to plug the temp sensor back in. It will screw up the whole day.
7. Cleaning K&N filters. After washing, I'd let that thing stand in a corner for a week to make absolutely sure it is bone dry before applying any oil again. I would not want any moisture interferring with oil distribution on the filter.
8. You are going to get busted for the "rice" stuff. Just use some other vegatable - we'll know. We have a place right near my office called extreme imports. They have outrageous crap-box cars. Like RJS said, they have a 15k to 20k car with 10 to 20k spent on the car. They could have just bought a used Vette, BMW, whatever - true sports car. What do I know. I'm 36 and a geezer to the people that buy this stuff.
9. A/F ratio. You don't need it for what you are testing. You won't be changing that at all, and I would not consider anything that did. I used it and it was very helpful in understanding what the #$$&$# MAF was doing (or wasn't doing). It's supposed performance was from changing A/F's at WOT. Of course it was a sham. Live and learn.
You are right on about the computer chip and MAF stuff. I've seen the Aurora run richer and leaner than stock A/F and each time the power went down. The factory setting seems pretty good.
Funny thing - that stupid MAF may have helped a little with the screen removed but the A/F was so wrong the thing was crap. If I ever visit the dyno again, I'll test it again since it has been set back to factor A/F. My hope is + 2 HP from it. I would not be surprised at all if it did nothing or still went down due to an inability to read the air flow correctly.
You just can't beat actually measuring something as opposed to theorizing about it.
Also - after seeing how much media the exhaust has to pass through, I realized how insignificant the MAF screen is in comparison.
There are a lot of other factors like the gas flow turbulence and direction when it hits the screen or media, but that converter sure seemed a lot more than the MAF screen.
Any thoughts? I notice the Magnaflow converters really don't even make a HP claim or explain why it's better. Something tells me it's not.
I thought most hi-po convertors had a larger chamber in them and therefore more of the cat media. i.e. it was bigger around even if the inlet/outlet were the same. The exhaust would still travel the same length, but there was more capacity for the convertor. I suspect that they don't make huge gains (and I suspect that the convertor is sized to flow at the same rate as the rest of the exhaust piping), and really I'm not inclined to mess with them as they are monitored by the OBD-II, and there are tough penalties for it. I'm no greenie, but I do like that the car is an LEV and I personally wouldn't replace the cat unless the original conked out. A high-flow will also probably increase the amount of engine noise you hear too. Since the Corsa is designed to minimize the cruising note, and everyone here seems to want their car to retain some civility, I would think that would be a reason right there not to mess with the cat. I've heard cars after the cat has been hollowed and it made a very noticeable difference in the amount of sound produced.
http://www.thecarconnection.com/index.asp?article=5042
Also of note is the Firehawk treatment of the Pontiac Firebird. This is a car that makes 305 hp already, and the SLP Firehawk bumps it up to 335. This is about a 10% increase (just a bit less) in power. The Firehawk has a much freer exhaust than the standard Firebird, and a cold-air induction like we will never have on the Aurora. I don't think any of us would be willing to go with an exhaust as free as the Firehawk because our Aurora's would be horrible to drive. Although, I suppose you could state that the Firehawk exhaust is similar to the Corsa because they are a similar improvement over differing bases. The regular Firebird exhaust is nowhere near as quiet as the regular Aurora exhaust, so maybe the gains would be similar. Anyway, the breathing for the Aurora will never match the flared, cold-air-gulping nostrils (or placemat sized air filter) of the Firehawk. So, I really think that 20-25 horsepower from the Aurora is probably achievable, but is probably about the limit we should expect.
Even the Regal GS and Grand Prix GTP gains are only about 30 horsepower (the GTX version of the GTP, which just includes the composite hood with ram-air intakes, K&N, and free exhaust only add 20 horsepower. This mod is the closest to what we can do to the Aurora, but still includes a CAI that we could never hope for.), and they include better induction, a freer exhaust, and also a bump in the supercharger's pressure and computer tuning to match it. That is something we don't have an option of on our Aurora's. So if a similarly powered GTP with 240 horsepower is bumped to 270 by a major change to it's induction and exhaust, then I think if we could get 270 horsepower out of a 250 horsepowered Aurora by also freeing the exhaust and hoping to reducing the intake vacuum some, we are doing pretty good.
They have a 225 horsepowered Monte Carlo SS package too. This is a 200 horsepowered engine stock. But, they make internal changes to the engine in the form of higher-lift roller rocker arms to achieve this. It isn't just bolt-on stuff. They also use 160 degree thermostats on all but the Camaro/Firebird (probably because these two cars will actually be warrantied). Personally I don't think the low-temp thermostat is worth the risk to your engine (via degraded oil performance) or the poor performance of the heater in the winter.
I realize that all of these cars are pushrod motors, not high-end breathers like our 4-valve Aurora, and so the gains to their torque curves are more telling than their horsepower gains. Also, the Aurora would probably see more of a peak horsepower gain from a peak-torque gain than the pushrod cars because the Aurora's torque peak is closer in rpm to its power peak. Therefore, supposing the torque gain tapers down gradually, the Aurora would have more of that torque gain still there by its power peak, and thus have more of a power gain. But still, I think a gain of 15-25 horsepower, and maybe around 20-30 lb-ft of torque is about all we should expect from intake and exhaust changes without touching the engine.
You will notice that the gains Corsa advertises are approximately equal for a Viper, Corvette, or the STS. Actually I think the STS is more. Yes, it's all about the stock exhaust on the performance cars being pretty free already. There is a lot to open up on a Caddy.
I'd think the Corsa system is about as free as you can get. After all it's all straight-through. It's 2 1/2 inch. You could make the plumbing bigger, but I'd imagine it's pretty wide open.
As for the MAF, I hear you. That's why I think Taylor shouldn't bother unless the mods don't make power gains that seem reasonable. That's why you looked at the A/F right? Because the Granetelli MAF wasn't helping the power.
I really feel like if someone can squeeze 270 or even 265 horsepower from their Aurora without ruining the smoothness of the engine, then they have done a good job.
Heck the simple K&N gets you to 259. I sure expect an exhaust system to add another 11 - easy. Another mod to the intake - maybe not, but I would not expect a good mod to the intake and another on the exhaust to not factor into the diminishing returns thing. In fact they should compliment each other.
I'm basing the 11 on what Corsa and the other exhaust companies have said/claimed (actually being very conservative based on their claims). So I really think 270 to 275 should not be to much of a stretch. For some reason I think 280 or so would be the limit without engine mods.
Again, only the dyno will give you an idea. I remember reading so many posts about how K&N's really don't do much, but they do. MAF's - oh they are great (I believed it too) but it has not proved out at all.
Come fall, I'll probably want the Corsa and if so, I'll be dying to hit the dyno. So it will be settled. It will be more rough, I'll just have to base the results on old baselines, but a general idea of whether it's +15 or + 10 should be attainable. I did all my baselines in the fall too, so a similar day may help.
Previous post - cancel one of those "nots" in the sentence that has two.
However, I don't intuitively get the complimenting of the exhaust and intake. I can see that they might not diminish since they make independent changes to the engine.
A freer intake means the engine can get more air (and thus more fuel) into the combustion chamber so it can make more power from that. Also, it means there is a reduction in the vacuum some which is less drag (force) on the piston as it moves down. This drag means more of the force the other pistons are creating on their power stroke is being wasted to help the intake piston pull air in, so reducing the drag directs that power to moving the vehicle.
A freer exhaust means lower exhaust pressure in the exhaust pipe. This means that as the piston pushes up on the exhaust stroke, it takes less effort to push the exhaust gasses out the valve and on its way to the tailpipes. When there is more exhaust pressure (resistance) then it takes more power from the other pistons on their power stroke to push this exhaust stroke piston up. Again, if this pressure is reduced, then the piston consumes less of the power the rest of the engine is producing in order to expel the exhaust.
So I can see how these should be independent gains, but I don't see how a freer breathing exhaust can positively help the intake breath in, nor how more intake air, or reduced drag on the intake, can help exhaust to exit the cylinder. Maybe since there is more exhaust in the cylinder from the extra air/fuel then a freer exhaust helps get it out. However, when the piston moves from its low point to its high point, everything in its way will get displaced. It doesn't matter if there was more stuff in its way. Maybe all the extra energy produced by the extra intake charge gets used up trying to push more exhaust out under higher pressure, but that seems unlikely. If that were the case, then it seems like the engine wouldn't make any power at all since the "regular" intake charge's energy would get mostly used up expelling the "regular" amount of exhaust. Maybe the restricted exhaust coupled with more intake charge means that the exhaust stroke happens under much more pressure. The combustion chamber part of the cylinder doesn't really get cleared of exhaust because the piston doesn't move through it (I realize that there is supposed to be some scavanging from well-designed exhaust manifolds). So maybe the higher pressure that part is under, the more actual exhaust is trapped there. That might undermine the efficiency of the intake stroke since there will be more exhaust already filling up the cylinder. I don't know what exactly happens, but the complimenting of intake and exhaust gains has never really made sense to me.
Sometimes it helps to consider the extremes of an example to understand what is happening - or can happen. Consider this - a car is severely restricted on the intake for some reason and the stock exhaust is OK/typical. You put a low restriction exhaust on it. What kind of gains would you expect? Perhaps nothing. At WOT the gas is not so dense and the exhaust push from the cylinder wasn't having a struggle to begin with before the exhaust mod.
One could say - hey, that cat-back does not work, or only added 2 HP. But now you open up the intake and get gains from that. In addition, you test the exhaust mods "before and after" (you spend a lot of time at the dyno) and shazam - that cat-back makes more of a difference now. I think it's possible.
What if the losses in the exhaust push are exponential in some way to the density of the gas? I know it's exponential regarding the velocity, but the air/gas is compressible too and I'd imagine the density plays a big part and friction/energy losses may likely be a function of the density to some exponent greater that 1. That's what's really at the heart of my examples.
Bottom line - you could in theory restrict the intake (I believe) to the point where the exhaust mods (as a percentage even) would add little power. They aren't totally independent and at some point they can compliment each other - positively or negatively. Perhaps this is not always the case.
Without giving this much more thought, perhaps an exhaust improvement could seem "complimented" by intake improvements (easier to get rid of denser air), but the intake would never really "care" if the exhaust was free.
I think you hit it with "Maybe since there is more exhaust in the cylinder from the extra air/fuel then a freer exhaust helps get it out". Just consider any possible exponential function of density.
Now, you have to look at percentages too. That may be the stumbling point. A 4% increase to 270 Hp is "more" than 4% on 250. It's the same percentage though. Depends how you define "more". I'd have to admit it's only "more" if the % is more.
Anyway, that's my simple view. Relationships between two variables like intake and exhaust may not always be steady and constant over all operating points or conditions.
First thing I noticed was how much LOUDER it was when I punched it. It ROARED under WOT. Pretty cool sounding. At first I had my doubts on any noticeable performance gaines. It seemed to perform about the same (only louder) crusing around in my neighborhood. I needed to get out on the highway before I make any conclusions. I don't race around or blast my 800 watt stereo in my sub-division.
After my little highway spin, my conclusion is: There is a noticeable difference, there is MORE pull in the higher RPMS and tourque steer is more noticable. This Northstar is pulling like it never has before. Before my car would only barley chirp the tires with the new Dunlop Sport A2's. Now it will burn'em untill the traction controll kicks in like it did with the old Goodyear GA's. There has to be a gain in power! I'll have to wait untill tomarrow for the official #'s. This was only the intake kit, can't wait untill the bored throttle body add's a little more to that too. I didn't want to swap out the TB today, I don't want to do that twice, the intake only took about 10min.
Can't wait till tomarrow!!!
Gotta go, I'll be keeping everyone posted.
800wattAURORA
Saturday was the big day for me, tested out RSM racings Intake kit w/K&N cone and bored-out Throttle Body for my 96 Aurora. The guys at the shop were real helpful. It took forever to get out of there, 14 runs and 2.5 hours later, I was done. They only charged me $150 too, should of been $200 @ 80/hr, anyways they were nice guys and let me borrow some tools too.
Alright here's the numbers rated from the wheels.
Baseline @ 190.0 HP and ???.? ft-lbsTq (I'll explain later)
Intake @ 198.3 HP and 202.9 ft-lbsTq
+TB @ 206.7 HP and 214.0 ft-lbsTq
These numbers are from the best run from each set. Unfortunately the #'s for the baseline Tourque were lost???. It took a couple of runs (6 runs) to get that baseline @ 190.0 hp, the screen came up and I saw it and said that I was happy with it (thinking of Garnes Baseline of 189hp) When I was all done at the end, when we went to graph everything, that run was GONE. So I don't have the TQ#'s from my best baseline. Bummer. Next best baseline was 177.5hp and 190.7 ft-lbsTourque. Little low.
Number crunching time: figuring 190hp at the wheels=250hp at the crank, theres a loss of 24% from the 4T80E transmission. I figure that the Intake gain was 8.3 @ wheels making 260.9 hp @ the crank. Total gain was 16.7hp @ wheels making 271.9 HP @ the crank. More than expected, RSM claimed +19HP, I got +21.9HP.
Guys, need some help figuring out the tourque numbers. Figuring off of Garnes baseline of 189hp and 204 ft-lbsTq, he also lost 24% of hp though the tranny. On tourque he lost 21.54% of ft-lbs of tourque from the tranny (assuming 204 ft-lbs Tourque @wheels=260 ft-lbs Tourque @crank). Using those numbers, I lost 1.1Tourque with the Intake and a gain of 11.1Tourque with adding the TB. With those numbers, my final 214.0 ft-lbs of Tourque @ wheels is now 272.75 ft-lbs of tourque @crank. That number might need some adjusting, sounds low to me.
Over all I'm VERY happy with 271.9HP and 272.75ft-lbs of tourque, rounding #'s My Aurora is now a 272Hp & 273 ft-lbs of touque. The car want's just wants to GO FASTER NOW, or is it the driver? The K&N Cone added a little noise when asked to push hard, but no complaints here. I think this was a great gain for opening up the intake and forcing more air with a bored Throttle body, a gain of 22HP dyno tested is great. Can't wait till fall to throw on Corsa's exhaust, probably go dyno one last time for gaines on that too. Then I'll be done. I'm happy.
Garnes what were the dyno #'s from the Vette? All these test were with the bottom part of the airbox on and the hood open. Couldn't get bottom part out because one of the screws was facing up, meaning it was screwed in from under the car. How did you get yours out? Should I take it out?
Getting late, more on this tomarrow.
Later
800wattAurora
taylorsturf@attbi.com
Don't get hung up on the numbers! Just look at the change. May baselines were 189 HP one day and 191/2 on another. The results with the K&N and box were correspondingly 2 or 3 better on the day of the better baseline. The K&N and airbox mod did maybe .5 HP better and 1 ft-lb better on the first day than the second - whatever. Pretty darn consistent.
Just forget the 170-something HP run, something was not right. It could be the equipment and such. That's way off.
Your torque numbers seem a little low - for just the intake, but again, don't worry about actual numbers. Just look at trends and changes. That's all that matters. If the dyno and the computer equipment/program/whatever is reporting a true 200 ft-lbs as 190 or 195 - who cares. As long as there is repeatability and consistency, you can measure change and that's all that matters.
My thoughts - the intake mod may help at the very highest rpms the most and thus peak HP. I got a best improvement of +7 peak HP and +4 torque from the K&N filter. The K&N helps more in the 5000+ (peak HP range) than it does at 4400 (peak torque area). Now, the air box mod added no peak HP but added some HP going up. It helped peak torque though because this change improved flow in the 4000's but not the 5000's.
Your TB results are pretty impressive. Lots of HP and torque. Was that TB done a couple times with similar results? Same with the intake - was that just one run?
I agree with your 272 engine HP estimate, but the torque is probably higher. Here's why. I'm assuming your intake added + 5 peak torque. I got a little more than that just with a K&N and my air box mod, so +5 should be a safe assumption - especially since the HP numbers are there and are pretty consistent with my results. So, that puts the baseline torque at about 198. You finished with 214 - an increase of 16. Yes, the "loss" is very slightly different for torque than HP (my thoughts on that below) and it seems to be about .785. Therefore 16 lb-ft/.785 = 20. 260 + 20 = 280 lb-ft. I just find it hard to believe that the intake added no peak torque let alone LOSE torque. You had to gain something and +5 is an easy bet - heck, I got 5.5 to 7 peak torque.
I think the reason the "loss" on HP and torque are just a smidge different (barely worth noting really) is that perhaps the losses with the automatic transmission are indeed just a smidge different at 4400 rpm than they are at 5600 rpm. That's just a guess. I've used about .766 for HP and .785 for the torque based on the observed "losses".
Corvette numbers - I saw a dyno of the 2000 or 2001 vette on "crank and chrome" - I think it's now "two guys garage" or something like that. The vette is rated for 350 HP. The baseline was 265 HP I think. 265/350 = .757. The same as I got even though they are different drivelines and all. I can't remeber torque. It was on their web site too (which probably has changed). The K&N cold air intake added +22 HP for them at the wheels on that vette.
Air box bottom. Yes, get that off of there! With the hood up, it probably didn't hurt you, but with the hood down while driving I think it will. Removing the bottom of the box will expose a large opening below where a lot more air from behind the fender can flow to the cone. Mine had a bolt that held one end in. It is easily removed with a ratchet. The other side was really just held with a post (of sorts) that fits very tightly against the rubber sleeve on the air box. This is hard to describe, but there is nothing to remove with this other point - you just MUSCLE it out. Pull up and wiggle it. It will pop out. I hope that's what you have. I can see how this might look like it's screwed from the bottom.
Hope that helps.
Give me your e-mail or something. I'd like to find out more from you about the throttle body work. I used to live near you and drive up to the Chicago suburbs from time to time.