Did you recently take on (or consider) a loan of 84 months or longer on a car purchase?
A reporter would like to speak with you about your experience; please reach out to PR@Edmunds.com by 7/22 for details.
A reporter would like to speak with you about your experience; please reach out to PR@Edmunds.com by 7/22 for details.
Options
Oldsmobile Aurora: Modifications
This discussion has been closed.
Comments
a highflow cat has shorter bricks and is smoother inlets/outlets. which is why it flows more air. the shorter bricks is why it isn't as effective
thousands of people say highflow cats help. 2 people have said a rsm tb helps, 1 of them said there original was already super gummy. when i cleaned my super gummy tb i saw good results. even the cadillac 4.6 owners say the 80mm tb doesn't really do anything. there was at least 1 there, mark99sts i think??? said that he dyno'd it and got nothing. if the rsm tb really added 9hp at the wheels, shouldn't it have shown on those two graphs? should have shown even more on the 4.6
caddy using a 80mm tb in the new caddies is not relevant because......its a bigger.......yep.
what im saying is 80 is bigger than needed. put a homemade 90mm tb on there, think it will help? doubt it. doesn't gm'like 8.x diesel engine only use a 80? thought i read that somewere.
i think its more that its just to hard to admit your wrong
I fully believe that a cat can flow more if it does a worse job of catalyzing. However, that does not make it a worthwhile modification in my opinion, and it doesn't make it a high-flow replacement. It's a high-flow crappy catalyst. A piece of straight pipe welded in there would flow more too, and also do a worse job catalyzing. However, that doesn't make a better product than my OEM catalyst.
I could also just gut out my existing cat. That would flow more and do a worse job of catalyzing, and it wouldn't cost me a dime...
I am not interested in improving my exhaust flow by worsening the car's emissions. I assure you, I am not wrong about that. I suspect others here have similar feelings.
What are you frustrated about? The fact that we didn't all run out and replace our catalyst because you told us to?
I get tired of you repeating the same obvious stuff too. Things like: "everyone says it's great" as a retort to "how can it flow more while still having the same catalyzing effect?" Or: "The caddie motor is bigger" as a counter-point to "having the throttle body bore match the sleeve and intake manifold opening would smooth the flow". Maybe those seem like good replies to you, I don't know. But they don't to me. They don't address any of the points you were replying to.
Greg (and I) may be sarcastic as well, but the key thing is that he inserts his sarcasm after making a logical point... This is a lot different than using sarcasm as the point.
Feel free to post any reply you want. But before you do, may I suggest reading through some of the archives here? Take a look at the level of explanation people tend to use when making a point. Take a look at some of the off-the-wall posts by trolls, and the replies to those trolls. Then re-read some of the posts you've made. See how you think your arguments measure up.
I don't dislike you or think you are immature. And I certainly don't take any of your posts personally. I do think you need to have more substance in your arguments, though. Maybe you just need to wait a bit before you reply to posts, give yourself time to get your thoughts together and organized. Or maybe I'm just some crotchety jerk, I don't know...
I never said the high flow cat wouldn't help. In fact I also remember posting that if it indeed is light enough on the substrate as to cause a code to be set in the computer, that it's probably less restrictive. I doubt it's a lot of power gain though. A thinking person would wonder why the company selling these units would resort to posting a hokey problem riddled dyno graph. Maybe if they showed the truth that it added power - but less than the 9HP or whatever they are saying, people would buy far fewer units. As for "feeling" the power. You just aren't going to feel much in the 5 to 10 HP range on a 4000 lb car. Get real. A little something - sure. If you think you are getting results in the 10 to 20 HP range - again get real.
As for the TB arguments, you seem unable to grasp the basic concept that the larger TB could be an improvement for both the 4.6 and the 4.0 to DIFFERENT DEGREES. You cling to that overly simplistic "it's a bigger engine" explanation like Linus and his blanket.
The fact is that a 75mm TB was used for both the original 4.0 and 4.6. It was not the best fit or design either with different diameters for the TB, the plenum, and the intake manifold. For the new Northstar, the TB is bigger even though the displacement is the same. Perhaps the VVT creates some air flow characteristics that increase the need for 80mm vs. 75mm, but again, I highly doubt it's an all or nothing comparison with the 80mm being 100% helpful at adding power for the new Northstar and 0% helpful with the old. And I'll say it again - the old TB design wasn't that great from the standpoint of creating a smooth flow path, so even ignoring the diameter, it's a better flow design. Now, can you comprehend this or is it going to be "but it's a bigger engine" again?
As for temperature - I sure hope you are not making the assertion that a hotter engine means the intake air will be hotter. If you do the math, the intake air is in contact with the ductwork., manifold and such for a tiny fraction of a second. There is no time for heat transfer. In addition, there is very little surface area to contact the air in relation tot he volume flowing. The effect on air temp will be negligible if anything at all.
Usually when you do a dyno, the hood is open, so the hot air off the engine should not be much of a factor. Of course if you have an intelligent intake set-up, you will be pulling air from behind the fender - not the engine compartment anyway. Hot air off the engine is very bad. Cool air flowing through hot engine components has little effect.
Your comments about someone else's dyno results as being the end-all proof in light of the fact that these tests were accompanied with some sort of problem and engine code being set is ridiculous. Perhaps there is much more to the story that I don't know, but from what's been posted about these TB dyno tests something went wrong. There is no reason a code should have been set for simply changing out the TB. Something was screwed up. This is not a problem others have had and there is no logical reason for it other than something was goofed - like maybe pulling the temp sensor with the engine idling when taking the intake apart (just an example). That'll do it and cause power to drop. When you have a code set like that, the computer will often run the car differently like run it rich at WOT or something.
As for taking things personally - give me a break. This is fun. It would be more fun if you actually considered anything shared. If you haven't noticed (probably not) I do address your points with logic and facts. Conversely............... If you think this is bad, you should go way back and see how rjs and I have bludgeoned each other over differing views - LOL.
As for the closed loop thing - What's you point? Yep, I said it is in that mode when cold - basically until it's up to operating temp or close to it.
mrdubya - I'd love to race you. K&N, modified air box, smoothed the duct, worthless RSM 80mm TB and plenum, and Corsa cat-back exhaust.
RJS has a good point about the O2 and the codes. If you are going to set a code and have to put a fake out O2, why not just gut the converter? It's illegal is a good reason. I guess the "high flow" cat is legal - probably just barely. I wonder if it would pass emissions after some use though. For going to the track though, might as well just get a gutted converter.
LOL!! Man, the wife and I will have to come out there one of these days. Keep an eye out for a big parking lot or something near you where we can line 'em up...
If you look through some of these claims, they give you emission results. most cases switching out the oem to a highflow unit got BETTER emissions, probably because the oem's were old, but im sure the highflow would do more catalyzing than your 5 year old one garnes, maybe not rjs's yet.
http://www.randomtechnology.com/press.html
and they are from independant magazine tests, not random techs tests, so it shouldn't be "fake" or anything
if you were to replace your cat with a "highflow" one, you would very easily pass emissions. as ive posted before highflow cats are made of better (more expensive) materials to better help them filter ( i know they don't actuall filter but its easier to say it that way) but at the same time use shorter bricks, which apparantly outweighs the better materials.
I replaced my cat after the intake and exhaust were done, so i saw much bigger results than i would have with just a new cat. but i assure you it wasn't somthing like a new intake were you have to get on it a few times, then go, "yeah, it does feel a lil quicker". it was more like "omg, this is the best $100 ive ever spent". and im sure my oem cat was partially bad giving me better results, but you can't clean those out. for a fair comparision
the only reason im saying the 4.6 is bigger so its warranted is because you said somthing like, wow you should send those dyno graphs to cadillac showing how there bigger tb is worthless, the two engines arn't even close to similiar enough to do a comparision.
and RJS, i did posts actuall data as to why they flow better, not going to find them again.
did you two race or somthing? live close by? either of you run at a track? what times? i havn't, but someday....maybe in the spring when they open back up. id run you anytime garnes.......but im sure you live way to far away, have to stick with comparing track times
K&N, modded airbox, smoothed out ductwork, removed the extra airbox, worthless highflow cat, dynomax 2.5" cat-back, autobahn.
anytime
Question: Then why doesn't Greg's crappy worn out cat set off the "SES" light? Why would a new, great-filtering high-flow set it off? If if was even better at catalyzing, it shouldn't set the computer off.
Having worse emissions, and passing emissions, are not the same thing at all. I have known people who have gutted their cats and still passed emissions just fine, yet clearly their emissions were lower before doing this. Modern car engines in a good state of tune, and properly warmed up, have very low emissions in the first place. At least as far as the rather lenient state emissions processes are concerned (new car regulations are much stricter).
You keep mentioning flow of the cats. I don't doubt that the Random Tech or whomevers' cat would flow better. The reason they flow better is because they do a worse job of catalyzing. I fully acknowledge that point, and have since the beginning. It is thoroughly concievable that flow can be increased if you don't care about affecting the resulting emissions that are output.
Those articles on the Random Tech page compare their catalzying efficiency to old pellet catalysts. No doubt they can flow better and catalyze better than them. New technology can certainly improve both areas. But OEM cats use the same mesh substrate that Random Technology uses. They are the same technology. The Random Tech is very unlikely to do a better job of catalyzing your exhaust and also flow more.
As far as Random Tech using better materials, I seriously doubt that. The catalyzing agents in catalytic convertors are pretty standard, and quite expensive. They use metals like platinum, palladium, and rhodium. I don't think there are some better metals out there for this. At least not for the type of reactions catalytic convertors currently promote.
You really have to ask yourself, why would a company post a screwy dyno graph on their web site? I'll go so far as to say they are obviously fibbing about the SC 3.8 results. Why would they do this? That graph they have up there is a joke. I'd say they have no credibility because of that.
I haven't checked your link yet, but if the emissions are better, why would it set off a code on the computer? Obviously something's not up to OEM standards - not better.
"the two engines arn't even close to similar enough to do a comparison." - the truth is that the engines are identical in every respect except the 4.6 has a slightly bigger bore. Going down the assembly line they are indistinguishable. They are really the SAME engine. My comparison is valid.
Oh - autobahn too. I'm in Indiana. You'd lose.
I don't think they have been used for a long time. I've got the original pellet type on my 77 Monte Carlo. They are a joke.
Anyway, if such a comparison is made, it should further lower the credibility of this company.
I find the Aurora's current brakes to be very effective as is. The only problem I have is that when it is raining, the brakes sometimes are ineffective when I first press the pedal. I think this is due to the rotors getting wet.
This was a problem on my Corvette, in fact a pretty big-time problem. The wheels on that car had vanes that really threw air at the rotors (which is a good thing). It meant they really got soaked. I eventually put cross-drilled rotors on the car, and this really seemed to reduce the first-time-wet braking issue. I'm thinking maybe when the Aurora needs new pads that I'll get some cross-drilled rotors to go along with them...
Anyone do this yet? I bet someone has. I'll probably go with Autospecialty Powerstop rotors as they were nice quality and a reasonable price from Summit Racing Equipment.
i don't work for a highflow cat company, so i can't tell you how they really make there cats, but they do claim that its better materials, shorter bricks. its a good compermise between no cat and a oem cat, kinda ironic that you say you could just gut out your cat and get the same results, but at the same time wouldn't use a "highflow" model because of the worse emissions.
in a perfect world a honeycomb cat wouldn't ever get plugged. im not a expert but one thing comes to mind. the way that a cat gets plugged is unburned fuel getting in there right? when a car is cold, open loop, i thought they ran really rich? this is just memory from autoshop class. so over about 9 years (for me) id only assume that the cat would be partially plugged, not alot, but i know my car like all other cars has ran to rich alot over the years. and over 9 years im sure its lost some of its effeciancy too. and if you HAD to replace your cat, highflow is definatly the way id go, not even taking performance into account, there cheaper.
garnes, i wasn't saying there better, if there were the same amount of material then they'd be better (from what they say, we'll never know...) but they use less material, making them worse overall.
and garnes....anytime! you'd lose
either of you ever get track times? race eachother or what?
Unburned fuel is one of the things a catalyst works on. It requires oxygen for this to happen, though. Some cats have an oxygen pipe that brings this in, but that was more of an 80's thing. The PCM can ensure there is some oxygen left in the air to react with unburned fuel. Otherwise, they just come out the back as bad stuff. I'm not sure how they'd clog up the catalyst. Also, because it is a catalyst, it enables chemical reactions without using up anything. It can keep doing it forever.
In reality, I've examined the cats on my Corvette, which were about 10 years old. They were not clogged or crudded up at all.
I think the show car GXP had cross-drilled rotors, but the production Bonneville GXP doesn't as far as I know.
Why is 1995 the worst year for brakes? I guess in 1997 they got bigger...
Thanks,
Steve
hey MrDubya are you Mikes95 from the gmforum?
Good argument guys I enjoyed it. Alls I can say on the topic is that i have a highflow cat by Dynomax and improvement was minimal.
I'd be glad to send pictures to anyone who provides me with their email address.
Pete
And yes, if the .jpg is that large and you cannot edit, please simply provide a link.
Karen, you know us Aurora owners are all a civil bunch. We have taste and sophistication, which is evidenced by the cars we choose...
Thanks
I know this was some time ago, but I seem to remember Edmunds hosting discussions like "American cars - pure junk on wheels". Wow, talk about "be nice" - not to mention many other favorable human attributes............ And some of the moderators seemed to encourage this mentality as well.
Henri
"I know this was some time ago, but I seem to remember Edmunds hosting discussions like "American cars - pure junk on wheels". Wow, talk about "be nice" - not to mention many other favorable human attributes"
And yet I cant say the r i c e word.
I'm building an exhaust for X-mas. Anyone have any suggestions or input? I don't want one too loud except under WOT. I'm pretty sure a 3" would fit. I found a great site, exhaustprolinc.com they even have y pipes....
As for the exhaust - go for the Corsa STS system. It's expensive but incredible. I can send you all the info on how to modify it for the Aurora. Other's here have done well with Dynomax mufflers. Kayaman has some great looking tips, and you can always have a custom place bend you some bigger plumbing. 2 1/2 inch is plenty though. That's all the Corsa system uses for the STS. If you go too big, I think there is some possibility of creating some resonations and noise. As for replacing the resonator (gotta do it - it stinks) some sort of straight through muffler would work, but I'm not sure it would sound so great. The stock resonator is straight through, but is small in diameter and has a weird irregular (wavy) perforated sleeve shoved in it - not the best for flow. The Corsa system addresses all these things and even the resonator is designed with the sound cancellation so that it's large and straight-through but greatly reduces the noise before you even get to the mufflers.
Ill try to play nice karen!
My bud really likes Magnaflow. They seem to have the best performance/sound. I just need help with the muffler size. My current guess is a 5"x8" w/a 14" body? I thought a 4" round was too small and a 5x11 was too big. Also would my cat need an air or not?
Here's my current set-up list:
carsounds hi-flo cat to a Magnaflow magnapak (racing muffler acting as a resonator http://magnaflow.com/02product/pack.htm) to a Magnaflow mandrel Y-pipe to 2 stainless steel Magnaflow mufflers 5x8s out to some tips. I really like the look the Corsa tips give, gonna try and find something like those.
The piping will bend around a bit and will be some work for the custom installation.
http://www.pfyc.com/store/merchant.mv?Screen=PROD&Store_Code=- PFYC&Product_Code=GN5003&Product_Count=11&Category_Co- de=GPEXH
here's what a 4" bell tip looks like, do not go just single 3" tips, way to small, its what i had at first.
http://www.cardomain.com/memberpage/399198/1
not really good pics, it was a disposable camera
dubya, the first link looks its for a dual outlet muffler.
Anyone have an idea of the muffler size? I'm thinking 5"x8" w/a 14" body?
Also would my cat need an air-let or not? I was thinking if I just got the one with it I could just cap it off and use it later if it sets anything off...
Henri
P.S. I dont know if I followed all taht was being said by MrDubba, garnes, et al. BUt does it even makes sense to put the Corsa system on the car? Will there be any real (not seat of the pants) difference in the car?
Henri, are you freaking kidding with your Corsa question? You've asked that several times before, and been answered every time. Not to mention all the other people that have inquired about the Corsa system on a classic.
For kicks I did a search, and Henry is asking about the Corsa as early as post #21 on this thread....
Hey, can you imagine that I said this at one point??
The more I listen to my car, the less I think I want Corsa's. When you punch it, or even just lean into it, it already makes a nice (if a tad subdued) growl. I think it has enough of an aggressive tone for me. Plus, the cruise is sooo quiet. I guess the Corsa is appealing because it is different. But I really like it the way it is. I think Garnes made the right move by passing on it.
Man, I'm glad I eventually came around. The Corsa sound is soo sweet, and I can't imagine driving the car without it. It is so much a part of the luxurious yet sporty nature of the car. There is no way I would ever switch it back, and I swear, I think part of my next buying decision will be "does Corsa make a system for this car?"... Hopefully they'll have their CTS-V system out by 2006...
Seriuosly though, I saw the Corsa system on ebay for $840 and thought about it. However, the guy said that he only had the system for the 99-2004 Seville. The platform for the seville is the same for the Aurora, but only for certain years. I thought 96-98 were the years so I asked for the kit for a 98 STS. He said he did not have it. Hence my question to this board. I believe the STS and Deville no longer share the same platform as the Classic but is the same as the 2001 Aurora.
Second, I never said I understood the math behind that whole debate between the "time travel" guys.
I just want to know if I am wasting my money on the Corsa cause I will not see any real improvement in performance. Greg seems to be saying there is no real perfromance improvement with the Corsa, only seat of the pants thrills.
And yes, I have been debating this purchase for sometime. I now have a few dollars to throw into the car (BY CHOICE) and am looking at my options. Though I must admit I am a little concerned about the steering acting up.
Henri :>)
know what size muffler I should get? I was guessing in the middle, 5x8 w/a 14" body?
Henri, seriously, read back to some of the posts about the Corsa. It is probably the single most-discussed modification on the board.
I think you will have a significant gain of at least 10 horsepower. The OEM chambered type of muffler is very restrictive, with the flow making several 180 degree turns. The Corsa's are straight-through and also a tad wider. I think they will reduce the effort required by the pistons to push exhaust out, thus freeing up that power to go somewhere else (like out the crank).
I think you are getting confused about the catalytic convertor. The argument there was that it was very unlikely to increase flow or free up power and still have the same catalyzing ability. I think that this has been shown to be true. If you don't care about increasing your car's polluting just to gain a couple of horsepower, then maybe you want to consider this too.
In my opinion, though, the Corsa is worth it even if it didn't give the car more punch. The sounds that shoot out of those quad tips is just heavenly.
If you look at the Corsa website, the only Seville they make an exhaust for is the 1999-2004. This is the only Seville system that they make, though I don't know why the 1998 model year isn't included as it was the same car. Also, it wasn't until 1998 that the Seville moved onto a version of the Aurora's platform. So this is the exhaust you will want to buy. And as Greg and Taylor have said many times, you will need to have a shop make some tweaks to the pipes. It won't just bolt up the way it is and fit right. I'm quite sure you could ask Greg to mail you the photos and description of the modification he had to have done for it to fit (unless he's already mailed them to you two or three times, in which case maybe he'll tell you to shove it).
I really, really hope you decide to get the Corsa, Henri. I used to hope you'd get it because it is such an incredible product and I knew you'd be thrilled with it, but now I just hope you get it so that six months from now I don't have to read a post from you asking the same questions about it... :P
<<KISS>> <<KISS>>
Hey, all kidding aside, you will love the Corsa. I don't think anyone that buys one could say anything bad about it. And the Seville system is the one you want.
Some things I'd look into if I bought it from Ebay:
- How old is it? (I'd just be curious)
- What shape are the tips in? The rest will probably not look new, but will look ok. You could polish it up, but it'll just look dull again. But the tips should look awesome and not blackened.
- How much will it cost to ship?
- Will Corsa honor the warranty?
- Will it come with all the clamps and instruction?
If it's only $150 less than brand-new, then being warrantied or not may make a big difference. Stainless steel clamps could easily cost you $50 or so for all of them. You may also want to find a shop you like/trust before you get it.
i undersand rjs getting corsa, your cars pretty new. me, my cars a 95, high miles, resale sucks, i couldn't justify that much for exhaust, i paid about $450-500 for parts and labor
then again, im also a broke college student
but if i get a newer caddy or aurora, id definatly get corsa. isn't it gm certified or somthing, so if your dealer is really anal about mods, with the corsa they cant deny you warranty stuff can they?
Way back, I wimped out at first and was afraid of too much noise. I had no experience with this sort of stuff, so I was probably overly cautious. Finally, I changed my mind and decided to just do it and was thrilled from the first second. All I can say is:
1. You will get a nice performance increase. It's most noticeable when punching it from a roll of 30, 50, - even 70 mph. The car puts you back in the seat harder at these higher speeds and higher rpms. Yep, that's just seat of the pants but see No. 2 below.
2. This is the one mod I could not dyno because a back to back comparison was not possible. In addition, Corsa has provided a very credible looking dyno graph of their tests on the STS. They sent it to me long before they ever put it on their web site. The STS saw a 21+ HP increase at the wheels. I doubt the Aurora gain is as much but I think RJS's 10 HP at the wheels is a good number you can take to the bank and it may be considerably more. My guess is that it is.
3. The stock exhaust does stink for flow. The mufflers are highly restrictive, and the resonator is not too encouraging either. Going from the stock 2 1/8 inch piping to 2 1/2 is actually a very large increase in flow area - thus less restriction.
4. You need to find a shop that works with 304 stainless steel and is therefore familiar with working/building custom exhaust systems. The STS system will work on the classic Aurora with some modification.
5. If you REALLY want to do this, just find a shop, share some installation pictures with them I can send you (my guys worked it out nicely), and then just pick of the #%^*^ phone and order the darn thing already. Have them send it directly to the shop.
6. It's totally quiet on the highway at any speed really. Acceleration sounds too good to describe and the performance is there to match.
And yes, the same thought also crossed my mind about any future cars. Is something from Corsa available??? Even the new GTO - it's exhaust supposedly sounds so tough, but I bet it's still baffled. It's probably not as bad as the stock Aurora, but I'm sure Corsa will make something that's straight through for it that sounds even better.
Also, anyone know a cheap place for the 01+ 17"'s?
To maintain the stock tire diameter of 27.1" you will need to mount 255/45 tires on 18" wheels; that would give you 27.04" diameter -- very close to stock. 235/50 would give you 27.25" which is fairly close to stock. 245/50 would be 27.7" and 245/45 would be 26.7"; I don't know if these last two combinations are close enough to stock to be OK. When I was researching tires, I found that there are few brand/model choices in these sizes.
I bought four 01+ non-chrome 17s on eBay for $202.50 for the set plus $68 shipping (NC to NJ). They are near perfect and included the caps. You could say I got lucky, but I had been looking for two years. Usually the eBay prices are around $800 to $1000 per set. I mounted Continental 255/50-17 100W ContiExtremeContact tires (27.04" diameter); they are awesome.
You could try www.car-part.com; they list used parts in salvage yards across the USA. The prices for chrome range between $50-350, non-chrome $100-200.
If you want to go with new, Van Chevrolet in Arizona has the best prices I know of; look them up on the web. Chromes go for $414 each ($592 list) and non-chromes are $369 ($527 list). Shipping extra. Good luck!
My wheels were the factory non-chrome wheels that had been stripped and then chromed. They are OK, but I'm not sure I'd recommend them. They hold up fine in summer, but last winter (exceptionally harsh) got them pitted somewhat. They still look great, but I wonder what they will look like next spring.
Anyway, be careful of aftermarket re chromed jobs. Some people have had great luck, I'm only somewhat happy. I think AAA rims is a big dealer in re chromed rims. I'd have to look up the company I got them from, but I wouldn't recommend them.
I just read the Tire Rack survey results for the Eagle F1 GS-D3 -- awesome for a summer tire. One reason I stayed away from Goodyears was that none of the performance models had even 300 tire wear rating. The Continentals I bought are ultra high-performance all-season with a 400 tire wear rating.