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Pontiac Bonneville



  • Whats FPR , did I miss something ? How was gas mileage on your trip with the P injector ? Have you tried the 3.25 pulley yet ? I'm very happy with my cars performance right now , esp. in the cooler mournings and nights we have been having here the last few weeks . When outside air gets below 45 and it's damp this car is very strong
  • snicklesnickle Posts: 147
    Fuel Pressure Riser. One of the current theories is that with the high boost of the smaller pullies, the car tends to run too lean at WOT. That contributes to the KR problem. The fuel pressure riser increase the amout of fuel injected into the cylinder, during the period the injector is open, hence a richer mixture and less KR. From everything I have seen on the boards, it definetly helps, the current thing some GPers are looking at is a 3.1 pressure riser the tracks fuel requirements, so it ups the pressure as the engine wants more fuel. Helps keep the mixture from being too rich at lower rpms. Of course the computer keeps that from happening for long, but that then affects how much fuel it will give it at WOT. So an adjustable intellegent pressure riser seems like a good idea.

    The PVI does not seem to help as much on long hauls. I am going to talk to tech support tomorow and see what they have to say. The guy I talk to in canada says the canadan group only see returns on 2% of the unit, while the US group sees a 35% return rate. He attributes that to tech support. The canadian group works alot more with the user to fine tune things.

    The other thing I am looking at is water injection. I have had few conversations with people who have done this and they have seen good results. One guy is testing an FPR with water injection and a 3.0 pulley. It looks like their are a couple kits that should work. ERL Aquamist and Spearco. The Spearco is cheaper, but I can;t find a GTP owner who has put one on yet. The ERL is fairly popular, but expensive. YOU cn also build one but it seems like a lot of work. I may try the Spearco unit with a 3.25 pulley and the composite throttle body spacer from RAT. The spacer makes it easy to attach the injector, just tap the spacer and you are all set, without having to make unrecoverable changes. I am meeting with an exhaust guy on tuesday to price him putting on a couple flowmaster 50 series delta flow mufflers. I am keeping the rest of the exhaust stock for the time being. I like the current tips and flowmaster recommend keeping the resonator, unles I was building a complete brand-new cat back setup.
  • Fuel pressure riser , dumb me , I should have remembered that cause it's an upgrade I want to do. One reason I have left the car in it's current state of modification is I'm finally happy with it's performance , not to say I wont be happy with more ,I know I'd like about 40-50 more hp , but in this cooler weather that SSEi is an ANIMAL !
    In addition to the 3.25 pulley , short Gator Back SC belt , 185 therm. and the altered Thrasher cold air induction I run 94 octane Sunoco and NOS octane booster or 100 octane racing fuel (the better of the 2) .
    Sway bar mod will most likely be next for me , sounds like your getting close to a muffler upgrade . I'm I right in thinking you changed brands of low restriction muffler's your looking at ? Good luck and happy SSEing . Doug
  • Last night I bought my wife a surprise gift , a 99 Grand Prix to replace her Chevy . Unfortunately it's not a GTP or even a GT , it's an SE with the 3800 engine , single exhaust , but for $11,500 with all the toy's except moonroof and leather I couldn't resist . Not to mention it gives me some base to compare late model GP's to my 2000 SSEi for further mod's of the CAI alteration's I have already done .
    My dilemma now is should I take the K&N replacement filter out of my 93 SLE bonnie and put it in her 99 GP or keep it , hmm
  • ezraponezrapon Posts: 348
    St. Louis is seeing 40 degree temps. I have installed the 3.4 pulley and K&N element. I'm going to check out the new Midas low restriction muffler (10-15 HP gain, so they say) tomorrow. The car has hit 4000 miles it has a crank full of Mobil 1. All of these things combined have changed my little black sheep into a black monster. I'm not going after the Lesabres or GP GTs, I'm hunting camaros and mustangs. I think the next move might be a tranny cooler... who where and how much... give me a hint!
  • snicklesnickle Posts: 147
    The coolers are 50 -60 bucks. I had a quote of $100 to install one.
  • ezraponezrapon Posts: 348
    The new hi-flow muffler from Midas is called the Raven. It is black and looks like the factory set up. To have them welded in with factory tips will be right at 300 bucks... does that sound reasonable...anyone else go down this road yet? The GTP site has tranny coolers a bit cheaper, I e-mailed them to see if they might fit the SSEi. It depends how the lines are routed and the mounting position. I guess every thing will have to be fabricated anyway.
  • ezraponezrapon Posts: 348
    Midas, after looking at the car said to lose the muffler behind the cat... replace resonators with raven mufflers... any thoughts on this idea?
  • snicklesnickle Posts: 147
    The thing behind the cat is the resonator. The you have dual mufflers. Several of the people I have talked to, think the car wwwill be rather rude without the resonator. I am planning on just replacing the mufflers with flowmaster dynaflows. Thought if you eliminate the resonator and goto high flow mufflers, performance will increase. I wonder how loud it will be.
  • snicklesnickle Posts: 147
    I bit the bullet and ordered my flowmaster 50 series deltaflow mufflers today. Should be in by the end of the week. I'll try to get them installed next week. $193.78 including shipping.

    I am leaving the resonator (for now) in place.
  • ezraponezrapon Posts: 348
    essentially, if I yank the resonator and replase the stock mufflers, I will have installed a cat-back system. I belive it would flow quite nicely. Does the computer rely on the back pressure created by the resonator for command functions? Do GTP's have a resonator in place when they go with the cat-back? I could handle a little more noise... something in the camaro or mustang range would be acceptable. My Grand National had a nice Formula 1 type rumble that was quite pleasing; so I know the 3.8 is capable of sweet sounds. Dealer finaly got the rATTLE OUT OF THE Door... locking mechanisim was at fault. GTP guy said the air box for our cars and the GTP are the least they have the same element... is this true...I know somebody just bought a GT???
  • snicklesnickle Posts: 147
    The GTP'ers tend to yank the resonator or replace it with a third party. Lurking their board gets mixed opinions. Though, they seem to like louder than I am willing. Yanking the resonator, should not cause any problems. The cat should provide enough back pressure, to keep the PCM happy. I would not expect much low-end power loss, unless you make big pipe size changes or adjust the pre-cat system.

    The GTP uses a different airbox, dmckeown managed to get the thrasher CAI to kind of fit. Lot's of duct tape, I think. I am still building mine.
  • dmckeowndmckeown Posts: 107
    I bought a Trasher CAI kit meant for a Grand Prix and modified it to fit . The factory air box and the area it goes in are deferent between the two car's . I had to cut a triangler section off the top and bottom plastic sections that make up the CAI air box , about 2" if I remember . I made a cardboard model of the new air box and modified that until it fit and then cut the plastic one to match . In the GP there is an opening in the fender wall as well as the air inlet hole , we do not have this opening so I left about an inch of gap on the top ,bottom and drivers side of box . PCM sit under box on the metal shelf of fender wall with a rubber mat (sup. in kit) under it . I made Z bracket's to clamp it down . CAI box fits flush with radiator wall keeping hot air from that area out off intake on passenger side of box . Cold air flows in through hole in head light wall into front of box , also some goes over PCM as in factory set up . some air must flow in 1" gap on top and driver side also because I duct taped them closed and noticed a slight decrease in performance , took tape off and a few more ponys showed up again . I made a bracket out of angle iron that attach's to rad. support and front pass. side of box keeping it in place . Bottom line , I can def. feel the difference between it and the K&N slip in replacement filter in 0-60 and passing power . The only bad side is for the first minute or so after start up the intake noise is incredible , then it cuts back to almost stock level , that is until you get into boost out on the road . Then you will notice increased intake and super charger noise , but that noise is great , real cool and it gets noticed by people walking on the street or next to you in a car , sorta like the woosh of a 4 barrel used to be noticed accept you don't have to be flooring it , only into the plus side of boost . Doug
  • smfransmfran Posts: 432
    Do you miss your Grand National as much as I miss my '86 T-Type? My '86 would blow away my 2000 SSEi. Circumstances changed for me in '88 which required me to look in to 4-Doors. I switched from Regals to Bonnevilles at that time and do love them (this is my 5th), but My T-Type had no rattles, a useful glove box, and much more "get up and go". I do think that the SSEi accelerates faster from 60 mph to ... but the Regal was quicker off the line and from slower speeds to 60. There was no turbo delay when you put your foot down like I get with the supercharger. If you want to see the nicest Regal ever, post your Email address and I'll attach a picture
  • ezraponezrapon Posts: 348
    I miss my GN everytime I mash the accelerator on my SSEi. Those damn things were highly underated. An engineer at Motor Trend claimed them to be over 300HP.It did not handle or stop like the SSEi and it leaked oil probably due to high crankcase pressure. Mine turned 13.5 1/4 miles and 0-60 in just under 5 seconds. It was 245 HP. The SSEi is 240... biggest 5 HP in history. Must have been the intercooler.
  • ezraponezrapon Posts: 348
    I'll be glad to look at your t-type. Mine was an 87... a little faster due to computer mods to the boost duration. I will be forced to send you a picture of my 79 T/A anniversary model that I've kept garaged since new... if your ssei was in the pic, i would not be disappointed. email is.....
    [email protected] I'd like to see pics of everyone's car and mods if possible...except for the guy in the SE from last month who accused us of being muderers for liking speed.
  • snicklesnickle Posts: 147
    The lag we all feel appears to come from a couple places:

    Intake, exhaust and tranny.

    Intake: From previous post you can see HP number on my SSEi with a 3.5 and a 9" cone filter and Intense01 with a 3.25 and stock intake. Very similar. With the cone my RPMs and boost spin up much faster, however at WOT with a warm engine the KRs kill overall performance.

    Exhaust: Too much back pressure for instant throttle response under full boost. See later post.

    Tranny - Some autotap readings and guesses implies a fair amount of power is being lost in the tranny during a punch. It settles out, but affect the response.
  • snicklesnickle Posts: 147
    I ordered one over the weekend. I will put it on a little later.
  • snicklesnickle Posts: 147
    Since it seems I am the first on the board to be moving to a new exhaust, I thought I woudl make an attempt at theory. All comments and criticism encouraged. No flaming, please. My backgrouond is computers not physics and automotive design.

    A few assumptions:

    Less backpressure is good. - An engine runs stongest with no exhaust and no thing to block the air leaving the engine. A big pipe of each valve provides maximum power, assuming the PCM allows it.

    Backpressure is most important at the valves. - The only place back pressure affects the engine is when the exhaust gas is trying to leave the engine. The engine could care less about downstream in the exhaust other than how it affects it at the valves.

    All exhuast design is a compromise based on how the car is driven. - The exhuast for a dragster and a commuter car have to differ. For example: Volume matters more in a commuter than a dragster.

    Exhaust is a series of pulses not a steady stream. - as each piston fire the valve open and release a jet of 1700 degree gases, then the valve closes and another opens. Hence a series of pulses.

    Bigger, less restrictive does not always mean less effective backpressure. - At WOT bigger is better until a point, at lower rpms things differ.

    Low RPMs - at low rpms a jet of gas escapes the valvle and heads towards the tail pipe at a large velocity. The valve closes. The gases continue by intertia to move toward the tail pipe. If there is not room for the gases to expand (bigger pipe) then the leaving gases will create a relative vacuum behind them at the valves. That will help suck the next burst of gas out of the cylinder NEGATIVE (kinda of) backpressure. With a bigger pipe, such as large headers, the exhuast gas expands when it leaves and does not create a vacuum, so the next pulse hit a mass of slower cooler air it has to move out of its way.

    WOT - At wide open throttle things differ a bit, with a standard exhaust the engine is expelling gasses faster than they can move down the small pipe (an SC makes this worse). Here a bigger pipe helps to increase the flow rate. Above a certain size the air would expand too much, cool down and slow. Tough balance.


    REducing restriction without increasing volume will help at all RPMs, big difference at low rpms.

    Increasing volume will help early in the system will help at WOT but may hinder low end torque. Later in the system shoudl help both, as long as it is not carried to extremes.

    Did that make any sense? Does not talk about volume, tone or frequency issues, but htose are personal. I will post my thoughts on that later.

    PS Drone is caused by exhaust gases moving too slowly through a muffler or open area.
  • dmckeowndmckeown Posts: 107
    One of the two most disappointing performance characteristics of my car was the lag between WOT and the car actually starting to accelerate . Every mod I have done has helped to lessen this effect until now I am reasonably happy with it . Second was 0-60 time and that also has improved but not as much as 30 - whatever has . The most improvement was with the 3.25 and CAI , by that I mean the improvement over stock with the 3.50 pulley and slip in K&N filter was great , very noticeable . But the second level of mod's was even more noticeable over then first level the 1st compared to stock , see me smile ! Now my car at this level is still not a Grand National coming out of the hole and won't ever be , but it's under 7 secound's for sure , and from 30 on up it's big fun . So you guy's that do miss that surge you got from your GN's , stay with your SSEi's and this forum and don't be afraid to make changes to your car to get some more performance out of it . also , a late model GTP GP did get a 11 second quarter mile time recently , great for a sc fwd .
    And to that black wolf in sheeps clothing down in St. Louie , welcome to the small pulley club , who say's size dosen't matter ? Has your brother inlaw seen those SSEi tailight's yet in a grudge match or are you waiting to do more mod's ? See ya Le Saber ! By the way , the Thrasher cold air kit looks pretty good under my hood , shows off the red K&N cone filter real nice . The kit cost a bit and the mod's took me a few hours to figure out and implement but I think I have the only 2000 SSEi currently running a cold air induction , even if it is not the absolute best like a hood scoop . Have fun , Doug
  • ezraponezrapon Posts: 348
    In the 70's life was simple. You slapped on headers, a 4 barrel intake and Holley, put in a 50 dollar crane cam, tinkered with the distibutor and shaved off seconds of quarter mile time and made outstanding burnouts at the local hamburger joint. THESE were mods we did to our parents or family's car (we were a wild bunch back then). We would snicker when we heard the engine lope on my dad's 72' Catalina. He never realized we souped up the engine on sleep overs at friend's houses. My best friend's mom's Torino wagon was turning 13 second 1/4 miles... they had the trailer package which gave a nice ratio posi rear end. We basically didn't know what the hell we were doing, but we did it anyway... low end cam and a high end intake... stuff that didn't always work together. As I got older and wiser (I'm a teacher now) I messed with heads, valve springs, cam duration and induction issues. I made some fast Chevy's and Pontiacs. The Grand National was pretty much as fast as I ever needed to go...had a bumper sticker WARNING: I BRAKE FOR CORVETTES! It was cool but had no chasis dynamics or handling
    at all (solid axel). This SSEi has outstanding chasis dynamics and the potential for improvement (has anyone tested the stabilitrack and does in shut off when you defeat the traction control?)I think the front wheel drive platform has inheirent weaknesses that will never be overcome totally, but why is changing exhaust systems got to be so hard. I want to remove the resonator and go with twin mufflers (not nosiy). But with the talk of backpressure or lack of, I'm scared to touch it....I wish my son would borrow it and change a few things for me.
    P.S. The day after the 3.4 went on I embarrassed the Lesabre... I vanquished him earlier when the temperature was down in the 50's. Like my old GN, these things appear to be highly sensitive to the surrounding environment. I'd like to see pics of any intake or exhaust work anyone has done.
  • I recently purchased a 92 Bonneville SE, an I am trying to find out what kind of fuel consumption I should expect from this car; It is rated 18-28MPG, and I am getting about 21.7 in combined city highway driving. I have had other vehicles with the 3.8 V6 engine, and have gotten closer to 26 driving the exact same way to work. I tried highway driving and managed to get 23.6MPG.
    Is this the norm for a Bonneville?

    Thanks for any inputs or comments.
  • rea98drea98d Posts: 982
    My grandmother drives a 1992 Bonneville SSE with the NA 3.8 litre V-6. I kept track of fuel use on a recent trip from East Texas to West Palm Beach, Fla, and the car averaged about 28.5 MPG. I was actually disappointed in this performance, because on cross-country jaunts in my V-8, RWD Thunderbird, I get about 27.5. I was really hoping the Pontiac, with FWD and fewer cylinders, would do better than one MPG more than my T-Bird, but that's the way it goes. 28.5 is nothing to sneeze at.
  • snicklesnickle Posts: 147
    I don't think pulling the resonator would cause any real performance problems. It should improve overall and maybe cut a little into low end, but I doubt it. Just disconnect the battery for an hour afterward. Let the PCM recalibrate from scratch.

    My concern with the resonator is volume and tone. So I am going a little step at a time.

    The new muffler I hope to have on next week.

    My exhuast desire are:

    Eliminate the resonator or replace with an performance aftermarket.

    Go to 2.5 piping from cat to split for the mufflers. Leave the 2.25 after the split.

    RAT ported exhaust manifolds. I talked with them, the porting they do does not significantly increase the manifold volume, just smooth flow. If that is the case it should help performance without decreasing the post pulse vacuum.

    We'll see what happens at some point.
  • snicklesnickle Posts: 147
    Anyone going to try it?
  • smfransmfran Posts: 432
    I sent you pics of my T-Type and SSEi. It took about 20 minutes to upload. Please be patient when downloading.
  • ezraponezrapon Posts: 348
    Got the pics today...wish I has a DSL. As soon as the monsoons here in St. Louis stop I'll roll the firebird out for a Photo shoot. I see u have the pin stripe on ur SSEi. (SNICKLE) What are odds of finding an aftermarket resonator... if gtp guys don't have one available .... we won't see it. I too would like to eliminate it altogether, add 2 1/2 pipes to low restriction mufflers. I wouldn't mind an authoratative growl aka. like a vette, but not like a Viper or Harley. The factory put a hell of a lot of thought installing the factory mufflers didn't they?.....GO CARDINALS!!!!!!
  • smfransmfran Posts: 432
    No additional comments on the Regal T-Type? Don't you at least like the aftermarket American Racing wheels? What about my SSEi? Do you like the pinstripe or not? I'd also like to see a pic of your SSEi along with the T/A. I'm sure I'll have compliments for you.
    I'm sorry I can't root for the Cardinals, but ever since the '67 World series, us Sox fans need to back a different team. It can't be the Mets or Yankees, so I guess it will have to be either the Giants or Oakland!
  • ezraponezrapon Posts: 348
    OK, I loved the t-type. I always thought they looked cooler than the GN's anyway. I would have to see a pin stripe in person to evaluate it completely. I remember seeing 87 t=types with similiar wheels. Much better than the GN wheels. I just realize I sent the pics to the wrong guy. I hope dmckeown enjoys them (sorry I hit reply... the rest is history.) Some history in all those pics... my T/A a throw back to the 60's, big block, 4 speed, and 4-barrel. The t-type is a transistion between the T/A and the SSEi. The T/A is sooooo different than the SSEi. The 3.8 is like an electric motor driven car. Quiet reserved, efficent, and extremely high tech. The firebird is a viseral rush with rubber smoking, quadrajet roar, and slamming gears... they actually compliment one another quite well.
  • ezraponezrapon Posts: 348
    In a perfect world, the SSEi would have a shaker hood feeding ice cold air right into the induction system. They (pontiac)invented it with the gto, improved it with the T/A, and re-invented with the new Ram Air Firebirds...too bad the one car that would benefit the most, was left OUT of the cold. Everytime I hear air being sucked into my 400 (even at idle) I wonder why not an innercooler or tastefull hood opening... what are they afraid of... the STS has 300 HP.
This discussion has been closed.