GTP grand prix question
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From: The Bayou State
GTP grand prix question friends has a 04 Grand Prix GTP 3.8SC. Wants to put a new supercharger on it and remap the MAF would he need to change injectors also. Thanks for the help.
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From: Goldsboro, NC
First off like studdrein said the 04+ has a gen 5 M90 and as far as I know there is noone that makes an addapter plate for installing a whipple on an 04+. He might be talking about maybe P&Ping his M90 or getting one that has been P&P. He can't remap his MAF per say he could scale it down but he would be better off getting an 85mm MAF off of an f-body or 'vette and then installing it with proper tables in the PCM (requires a DHP Powertuner or HPtuners). If he is maxing out his stock injectors then yes he would need new injectors but that all depends on how far he wants to go. Do you know his mods now and what he has planned to do? Or better yet tell him to go over to Clubgp.com, go to the 04+ section and ask there.
Tate
Tate
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From: The Bayou State
Appreciate the fast response fellas. He just got the car and I don't know a whole lot about them. He is going to put atleast a catback on it and a CAI. I suggested to him just a pulley swap and I think now he might considering that instead of a new SC. Would ya'll happen to know of any sites that would have more performance stuff on his car? I like SLP and all, but I think on some of their stuff the price is too high. Thanks again.
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Joined: Jun 2004
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From: Charleston, SC
Check out:
www.zzperformance.com
www.3800performance.com
Those are my favorite vendors, have him spend countless hours on www.clubgp.com there is a ton of good info on there including mods for "newbies". You really want to make sure that you don't put too small of a supercharger pulley on that car unless you have the supporting mods. Detonation will destroy the 3800 pistons over times. If he stuck with a 3.5" pulley, he would probably be alright without any tunning and just intake and exhaust.
Find out what your buddies goals are. If he really want to get into the mods, I would recommend an interchangable pulley system (a hub mounts to the supercharger shaft and you can bolt different sized pullies to the hub depending on the how much boost you want to run) so he can drop pulley sizes easily as he continues to mod. I used to run different sized pullies in the summer and winter and it's nice being able to swap pullies in 5 minutes.
Just make sure you don't run too much boost without the supporting mods (cam, headers, Alky injection, intercooler, etc.). Avoid the one wheel burnouts (the GP has a weak differential), and if he wants to run in the 12's, make sure he has some money in savings because things will probably start to break. The 3800 can be put into the mid to high 13's (just bolt-ons) and still stay very reliable. Just have your buddy spend some time on ClubGP so he doesn't begin modding blindly, he'll waste alot of money in the long run, most do.....I'm guilty also
www.zzperformance.com
www.3800performance.com
Those are my favorite vendors, have him spend countless hours on www.clubgp.com there is a ton of good info on there including mods for "newbies". You really want to make sure that you don't put too small of a supercharger pulley on that car unless you have the supporting mods. Detonation will destroy the 3800 pistons over times. If he stuck with a 3.5" pulley, he would probably be alright without any tunning and just intake and exhaust.
Find out what your buddies goals are. If he really want to get into the mods, I would recommend an interchangable pulley system (a hub mounts to the supercharger shaft and you can bolt different sized pullies to the hub depending on the how much boost you want to run) so he can drop pulley sizes easily as he continues to mod. I used to run different sized pullies in the summer and winter and it's nice being able to swap pullies in 5 minutes.
Just make sure you don't run too much boost without the supporting mods (cam, headers, Alky injection, intercooler, etc.). Avoid the one wheel burnouts (the GP has a weak differential), and if he wants to run in the 12's, make sure he has some money in savings because things will probably start to break. The 3800 can be put into the mid to high 13's (just bolt-ons) and still stay very reliable. Just have your buddy spend some time on ClubGP so he doesn't begin modding blindly, he'll waste alot of money in the long run, most do.....I'm guilty also
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From: The Bayou State
He's looking for around 300whp maybe a little over and he said from looking on some website the car makes about 260whp and I figured just the basic bolt-ons ( int/ exh ) with the smaller pulley from SLP he should achieve his goals if that website he looked at is correct on the whp. Appreciate it guys.
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From: Toronto
yup that should get him to 300 no prob. Also try a DHP PCM upgrade, helps with the tune. I know with my 99gtp, i wanted to go to a 3.4 pulley, from a stock 3.8(i think pulley sizes for the 04+s are different sized off the bat). but to run a 3.4, i needed cooler plugs, pcm(even a general tune), CAI, 3" Down Pipe/u-bend delete(04+ exhausts might be a bit bigger), some said you might need a ported manifold....but the key is to SCAN for KR often!! The 3800 is a workhorse, but if i was to go to a 3.4/3.25" pulley with no supporting mods, Id probably have a cooked engine by now! I think with the above setup I MAY be around 300HP, so with an 04+ you should almost def be.
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Ran a SLP 3.4" pulley, K&N in the stock CAI, and the SLP cat back, went up to 10.4 lbs / boost (think stock was 7.9 lbs) on my S/C Regal GS. All worked fine w/ no issues, but read somewhere back then that a 3.4 isn't accepted by all ECM's. Really woke the car up.
Some of SLP's stuff is expensive, and the welds are a little frankenstienish on a couple of their mufflers I had. Had to paint them so no one would see the crappy workmanship.
Some of SLP's stuff is expensive, and the welds are a little frankenstienish on a couple of their mufflers I had. Had to paint them so no one would see the crappy workmanship.
Last edited by Kazmaniac; Nov 26, 2006 at 11:00 PM.
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Verdad Gallardo 12 Second Club
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From: Goldsboro, NC
Well they make about 260 horses at the fly, not the pavement. Check my sig, for mods and dyno #s. He can't just throw a 3.4 pulley on and call it done. The 04+ GPs or the Series III SC 3.8 (also know as a L32, not a L67 like the series II SC 3.8) is alot more tempermental then the 97-03s. Safely you can run a 3.5-3.6 pulley (stock pulley size is still 3.8, but the gen 5 blower on the Series III produces about 2 PSI more then a Series II, hince why you cant run a 3.4 on a stock 04+) good intake (CAI or FWI), and a PCM (either DHP, HPtuners or the like) without having to worry about scanning. If he wants something just to wake it up then I would recommend this:
1. Good intake (CAI or FWI)--$60-$250
2. 3.5 pulley--$65-$125
3. 3" DP--$250
4. PCM--$99
If he is serious about the 300 WHP then he will be looking a a little bit more again see my sig below.
HTH,
Tate
1. Good intake (CAI or FWI)--$60-$250
2. 3.5 pulley--$65-$125
3. 3" DP--$250
4. PCM--$99
If he is serious about the 300 WHP then he will be looking a a little bit more again see my sig below.
HTH,
Tate
Get an intercooler (wbodystore.com) easiest way to make 300hp. I'm making around 350 with bolt-ons, intercooler, cam, ported blower, ported TB, ported lower intake etc.. Wbodystore.com, intense-racing.com, and zzperformance.com are his best bets. Also SLP sells a 3.5 pulley, i don't think they offer the other sizes anymore. My buick is pretty fast, easily makes 12's all day long
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From: Toronto
yeah my bad, youd probably need a lil more to get to 300 WHP...., you probably have closer to 275 or so....been a while since dyno day....prob full exhaust, intercooler and a lil bit of port'n here/there
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From: The Bayou State
Thanks again. I will surely let him know about the websites and what to look for on the pulley's etc. I know I'll be the one putting everything on it so I want it to be right from the start with exactly what he needs so that everything goes well.
