95oldsVan Posted August 15, 2006 Report Share Posted August 15, 2006 What mods did you do to your GTP supercharger? Will a different pulley increase any HP and if so,by how much?Does that affect torque anywhere?If so what are the losses or gains? Is there also a ecm/pcm tuning you can do to increase power from the SC 3800 engine or is it mainly bolt ons? Also,does anyone know if the 3.8 or 3800 series can be punched out to 4.0 liters?If so what mods are needed to be done to make that happen for a 3.8 motor? Any info or links to exact questions would be very appreciated! Thanks! Quote Link to comment Share on other sites More sharing options...
97loudcut Posted August 15, 2006 Report Share Posted August 15, 2006 alot of people run the 3.4" pulley but since you will be running more boost with that you have to find ways to get the hot air out. Normal mods are PCM U bend delete 180 t stat CAI Autolite 104's (colder plugs) 3.4" pulley If you want some serious power intercool it and run a 2.8" pulley Quote Link to comment Share on other sites More sharing options...
terryk2003 Posted August 15, 2006 Report Share Posted August 15, 2006 http://www.zzperformance.com/grand_prix/articles1.php?id=35 read that!... Quote Link to comment Share on other sites More sharing options...
CSI_MuNkY Posted August 15, 2006 Report Share Posted August 15, 2006 http://www.zzperformance.com/grand_prix/articles1.php?id=35 read that!... damn! I should print that for when I decide to do my L67 swap... do all that work before I put the thing in! Jamie Quote Link to comment Share on other sites More sharing options...
no1kicker Posted August 15, 2006 Report Share Posted August 15, 2006 Read this too. http://www.clubgp.com/newforum/tm.asp?m=2867792&p=1&tmode=1&smode=1 Quote Link to comment Share on other sites More sharing options...
customgod227 Posted August 15, 2006 Report Share Posted August 15, 2006 Here is what I did with the GT...... ~L67 top-end swap ~3.8 pulley ~1.9 Rockers w/ 90# LS6 valve springs ~CIA~Ractive exhaust ~Resenator Delete ~SLP Headers w/ Downpipe ~Fully Portmatched ~DHP v1.5 ~Custom Built Trannsmission W/Shift kit ~HD Conversion~ Quote Link to comment Share on other sites More sharing options...
95oldsVan Posted August 16, 2006 Author Report Share Posted August 16, 2006 Thanks for all the great replies and info!I even bookmarked them links to read more later if I forget whats needed.Looks like decent,easy mods to do to get more stomp outta them engines. Quote Link to comment Share on other sites More sharing options...
95oldsVan Posted August 16, 2006 Author Report Share Posted August 16, 2006 Here is what I did with the GT...... ~L67 top-end swap ~3.8 pulley ~1.9 Rockers w/ 90# LS6 valve springs ~CIA~Ractive exhaust ~Resenator Delete ~SLP Headers w/ Downpipe ~Fully Portmatched ~DHP v1.5 ~Custom Built Trannsmission W/Shift kit ~HD Conversion~ Sounds real nice...what kind of power numbers are you seeing with those mods? Is it close to 280 or 300 Horses?Or do you need a cam and intercooler to get it around 300 or so?Just curious,still learning the V6 mod game right now. Quote Link to comment Share on other sites More sharing options...
customgod227 Posted August 16, 2006 Report Share Posted August 16, 2006 roughly 300-320 motor, so like 260-275 wheels??? Its nice, even nicer when I drop pulley to 3.4(3.0 GTP) and run alky. When a GT is boosted, the compression is higher, there for when a GT runs a 3.8 Pulley it is like a GTP running a 3.4. So when I run the 3.4, it is like a GTP running a 3.0. Just for people who do not know that... Quote Link to comment Share on other sites More sharing options...
terryk2003 Posted August 16, 2006 Report Share Posted August 16, 2006 just keep in mind...DO NOT just drop the pulley and expect to go faster...a car with 0KR and a bigger pulley will be faster than a car with KR and a smaller pulley...soo, do all the supporting mods first!... Quote Link to comment Share on other sites More sharing options...
runt Posted August 16, 2006 Report Share Posted August 16, 2006 I don't own the L67, but the article from ZZP was pretty good. Now I wanna spend more money on stuff....LOL. Quote Link to comment Share on other sites More sharing options...
Euro Posted August 16, 2006 Report Share Posted August 16, 2006 i dont even own a grand prix...but that makes me want one now.... Quote Link to comment Share on other sites More sharing options...
digitaloutsider Posted August 17, 2006 Report Share Posted August 17, 2006 grand prix / GTP / 3800 GTP For the love of FUCK, that engine came in more than one car. Also,does anyone know if the 3.8 or 3800 series can be punched out to 4.0 liters? The ZZP stroker kit puts you right over 4 liters. But really, who cares? Quote Link to comment Share on other sites More sharing options...
95oldsVan Posted August 17, 2006 Author Report Share Posted August 17, 2006 grand prix / GTP / 3800 GTP For the love of FUCK, that engine came in more than one car. Also,does anyone know if the 3.8 or 3800 series can be punched out to 4.0 liters? The ZZP stroker kit puts you right over 4 liters. But really, who cares? Me? Quote Link to comment Share on other sites More sharing options...
customgod227 Posted August 17, 2006 Report Share Posted August 17, 2006 I would say that I do have the supporting mods for the pulley drop. The only thing that I want to do is, add Alky Injection. That would eleminate all, if any, knock that I have. I had a scan done a couple weeks back, and It showed that I had 0 KR. So, hopefully, I am continuing that 0 KR!! Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted August 18, 2006 Report Share Posted August 18, 2006 right now i'm just taking care of maintenance stuff. after that i am probably going to lower the car along with GMPP suspension parts. as for powertrain modding, my plans are basically what everyone else does: - 180* T-stat - FWI - 3" downpipe w/U-bend delete and test pipe - 1.9 roller rockers with new springs/retainers - DHP PowerTuner - 3.4 MPS - Autolite 104s before i do anything i need to get an LS1M (portable/no laptop needed = nice). 3" catback, intercooler, cam and then a smaller pulley would be nice later on, but at that point it sounds like you'd need to start thinking about beefing up the transmission or have a built up trans ready to go in when the stock one fails. i don't want to go that far with my GS...it's not going to see the track more than once or twice a year anyway. not to mention i have another car i mod so wouldn't have the money to build a 12 second GS anyway. Quote Link to comment Share on other sites More sharing options...
john99gtp Posted August 20, 2006 Report Share Posted August 20, 2006 points to siggy and it ran a blistering 14.4 last week @ the track. Quote Link to comment Share on other sites More sharing options...
mfewtrail Posted August 20, 2006 Report Share Posted August 20, 2006 points to siggy and it ran a blistering 14.4 last week @ the track. What did you trap John? Temperature? Humidity? Quote Link to comment Share on other sites More sharing options...
john99gtp Posted August 20, 2006 Report Share Posted August 20, 2006 umm, mid 80s with very high humidity. the track was once again like a skating rink, and the extra humidity didnt help Quote Link to comment Share on other sites More sharing options...
terryk2003 Posted August 20, 2006 Report Share Posted August 20, 2006 umm, mid 80s with very high humidity. the track was once again like a skating rink, and the extra humidity didnt help wow, do i know the feeling...of course, the temps were in the high 60's with high humidity...but the skating rink thing...yeah...15.2@94mph...lol...rediculous....IDD better happen!! Quote Link to comment Share on other sites More sharing options...
pwmin Posted August 20, 2006 Report Share Posted August 20, 2006 by far, the best thing to get is a digital horsepower powrtuner. i absolutely love mine. i modded the riv, then demodded it and then bought it back and modded it again. heres what i had each time time 1: 3.25 pulley, 3.5" wai, 3" MandS production downpipe, 2.5" crush bent exhaust center outlet (dyno'd for best setup), R42LTS plugs (1.5 steps colder), 180 stat; 16.60 at 5800' time 2: 3.4 pulley, 3.5" fwi, same dp, 2.5" side exit mandrel, NGK TR55IX plugs (.5 steps hotter - colder and stock plug made it run like shit), 180 stat, powrtune: 15.88 at 5800' so, tuned with a larger pulley, better intake, and similar rest, i lost 7/10s in the 1/4. a dhp pcm is okay, but a custom tune is way better. Quote Link to comment Share on other sites More sharing options...
dbtk2 Posted August 20, 2006 Report Share Posted August 20, 2006 roughly 300-320 motor, so like 260-275 wheels??? Its nice, even nicer when I drop pulley to 3.4(3.0 GTP) and run alky. When a GT is boosted, the compression is higher, there for when a GT runs a 3.8 Pulley it is like a GTP running a 3.4. So when I run the 3.4, it is like a GTP running a 3.0. Just for people who do not know that... A 3.4 pulley on an L36 is NOT like a 3.0 pulley on an L67, I wish it was because my car would be quicker than it is, but its not. The difference is really about half that. A 3.6 on a L67 would be like a 3.8 on an L36, and a 3.4 on an L36 would be like a 3.2 on an L67. It only has 9.4:1 compression instead of 8.5:1. Quote Link to comment Share on other sites More sharing options...
no1kicker Posted August 21, 2006 Report Share Posted August 21, 2006 I would do exhaust first. Scanning with my GTP when it was completely stock, I had up to 2.8 degrees of knock at WOT, back in January. Quote Link to comment Share on other sites More sharing options...
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