'87 IROC-Z:
5.0L 305 LG4 - soon to be TPI
4 speed auto
3.27 BW POSI rear
no mods(well I plan to do the throttle body coolent bypass)
going by stock specs with carb......170hp/250tq.....thinking numbers will be better after TPI swap...how much I can't even guess.

'02 GTP:
3.8L V6 supercharged
4 speed auto
no mods
240hp/280tq

I can probably guess that the GTP would probably win but I was just wondering what you guys thought.

 

the GTP will win

 

GTP's are good for low 15's high14's....your gonna go down....do that TPI swap and some exhaust work....then see whats up...AARON

 

gtp will win. i only beat one by like 1.5-2 cars to 70

 

yup, same here, I raced a GTP 4 Door from a complete stop, him and I both roasted our tires and he hooked before me but I got him by 1-2 cars...I wanted to go from a 30 MPH roll...but he wasn't down for it - ARL

 

let me remind you fellas that with very very VERY little money, they can keep up with a stockish LS1... GTP, especialy the new ones are awesome... would like to get one as a beater, but that would make it faster then my sports car!... for now anyway... hehehe. GTP's gunna have ya unless hes a horrible driver.

 

are you crazy....a stock GTP will go high 14's or mid 14's at best, correct me if I am wrong, but I have seen some with great drivers going 15.3-15.0.....sure with a smaller pulley for the charger and some exhaust done, they are faster.....and whats the deal with this, " let me remind you fellas with very very very little money " crap, I believe money has nothing to do with going to the track, seeing them run and talking to the drivers about them. and Stock LS1's go mid to high 13's.....correct me if I am wrong once again....AARON

 

your wrong... i didnt belive it at first, untill i took a visit at some of the GTP sites... they are sick... minor money spend and there cars are hot little rides... I have seen the Bu's and the GTP's run 13's a lot at etown... low 14's to high 13's... and thats with some pulley action and some playing with the computer... how much could that be? 300 for computer, 200 for pully... 500 in mods... 13's for an already quick mid 14 sec car.

 

Ok, not every freaking GTP runs a mid 14s out of the box. Factory freaks might, but not every single one. I get so sick of people saying that GTP can run mid 14s, factory freaks can, the average will be low 15s. I am talking completely stock, no mods, stock filter paper, no track prep. I was able to run with a GTP from a 40 mph roll up to 75, and I started creeping on him, and that was in a Turbo Grand Prix that had exhaust and K&N air filter on the turbo. And the TGP only has 205 HP and 225 Torque stock. And I had no problem beating GTP in my 85 Iroc-Z, I took modded ones too, so I wasnt picking on completely stock ones.

I would say after you do a TPI swap onto your LG4 you will have a much better chance than with your LG4. If you have the money I would suggest getting some better heads for your car, will help out on top end with the TPI. I think after your TPI swap you should be able to run either pull on him out of the hole if you can get traction, at the least you should be able to keep very close to him out of the hole. I see your biggest problem being the higher RPM ranges because the TPI really dont breathe that well in the higher RPM range and the GTP does have a s/c, which will help it out. After TPI swap, w/o other mods, you will probally lose by a car or two. But if you start putting mods on your car, you will be much closer.

I have yet to see many GTP running high 13s just from a computer and pulley upgrade, I know there are a few guys with the pulley upgrades on factory freaks that bust high 13s, but those are few and far between. I would expect it more as taking exhaust and possibly a few other mods for the average GTP to run high 13s. If I am not mistaken, the quickest GTP is 10s or so(correct me if I am wrong), very respectable times, but still not that fast. I dont see all too many GTP punching into the 12s, either it is hard, I simply have not looked enough, or heard anything about them. Although I believe there is a guy that has a 12 sec Bonneville SSEi.

 

yea, it takes more then a pcm reprogram and a pullley, but thats heading in the right direction... I have seen a plenty of 13 sec GTP's and GS's at etown. I will get the complete list of mods from one of thoes guys next time i go... but i always see anywhere from mid 14's to mid 13's...

 

What kind of heads would you recommend? I have a really really really tight budget as is so getting heads used would be nice......especially if I can take some off a 350 or another 305 if they would flow better...maybe not off a camaro or firebird just another chevy small block. And would a cam out of a stock 350 be better then what I have? Only asking because I think my dad has a couple of 350s he took apart...one just needs a rebuild bad the other I think threw a rod. but yeah. Let me know what you guys think.

 

well if you had a mild 350, this would be no problem. 305 heads are tuff cause there arent much for aftermarket out there for us 305 guys... You have the SR 305 torquers, the L98 vette heads(ported), or stock LB9 heads(ported). Anything other then that would require you to mill the block down so the combustion chamber is not shrouded by the small bore. Also, what stock 350 cam? from what 350? YES you can get a bigger cam and will make more power. Dont sell your engine short. Ask in the motor board for anymore info regarding heads, cams, and intakes...

 

GTP (Freak) is mid 14's stock, and normally high 14's stock. With a smaller pulley and exhaust your looking at low 14's. With a 3.25 Pulley and full exhaust, high 13's. With an intense cam, mid 13's.


Many of my friends have GP's

 

not to sound like a dick but the turbo GP and the new GTP's ARE NOTHING, and I mean NOTHING alike...so don't compare the two...


Fact is you're gonna get wasted.....you really don't stand a chance unless he can't drive

 

I never said that they had anything in common. I stated I was able to run with one, stated the #s the TGP put out to give a general idea of what it might take to run with a GTP.

 

my best friend has a 91 GTP. (non turbo, 3.4 dohc V6) and its no joke. it beat my Z28 by bout half a car length up to 65mph. On the highway that car will haul *****. it has tons of top end power and speed. I can only imagine what a new turbo GTP would do. Also has anyone saw a grand prix GPX? they are a 4 door turbo 3.8 with ram air. they are meaner than hell. Watch out, the last thing you want to race is a new GTP.

 

I raced a 98 gtp 4door and Bandimere Speedway here in Denver in the Q-mile. And yep he got me by atleast 4 car lengths. It would be my choice for a family car with get up and go.

 

first of all , none of you guys with crappy tbi's should be racing anyone, there a disgrace to man kind,

17 seconds can't even beat my 94 6.5 turbo diesel,
tpi is slightly better , do to the massive tourque,

 

NOT A TURBO... SUPERCHARGER!!! 3.8 turbo is a GN, 3.8 SC is... well.. several cars now(Impalla SS, Monte SS, Regal GS, Grand Prix GTP) . All GTP's have a supercharger... I didnt mean to flame there, just making sure you got it! hehehe. The new GTP looks awesome, is faster and stronger. 260hp... the engine and supercharger are different only for teh GTP, the Imp and Monte get the older Gen II gtp engines... i dont know about the regal.

 

turbo? the GXP Grand Prix isn't a turbo dude..it's a supercharged Series 2 3.8

 

the Regal SHOULD get the same drivetrain as the GP

 

nice opinion but shame he has a LG4

 

true, but GM SHOULD still be making the fbody... we see how that worked... I like the TAP shift feature on the new GTP's. very nice, and they styling is very very sweet.

 

I guess this will never end. The bottom line is the GTP will beat you, and in my opinion badly. My Regal ran 14.5 with good gas and no air filter on a good day. Your car might run low 16's on a good day.

BTW, the 12 second Bonneville you were talking about is now an 11 second Bonneville- it ran a 11.8 here recently.

 

i raced an 97 i believe gtp 4 door from a 25-30 mph roll till 80 and we were dead even the hole way.

 

Here's the quick scoop on the GTP:
-240hp
-3500lbs
-Front Wheel Drive
-4-speed Automatic
-Power to Weight = 14.583 (smaller is better)

My 1983 Trans AM:
-180hp (new 305 engine)
-2900lbs
-Rear Wheel Drive
-5-speed Stick
-Power to Weight = 16.111 (smaller is better)

Sadly, the specs speak for themselves. I have an '02 GpGT.
1st Gear up to 45mph @ 5500rpm
2nd Gear up to 60-70mph (can't recall, don't push it that hard usually)
3rd Gear..... haven't gotten it close to the red yet.
4th Gear = Overdrive

The only way one could win is if it wasn't straight line. Then it's mroe dependant on driver than power. Straight line, he's got you beat bud. If it was a non-GTP (200hp), you'd win the power to weight ratio. Just remember that if someone pulls up to you in a "GT".

 

old post sorry

 

I currently own a stock '98 Regal GS, heavier and not as quick as a GTP, but close in comparison, and I formerly owned a 90 formula 350 TPI w/K&N, Hypertech, and Flowmaster catback. I never went to the track and my only experience is the butt dyno, but the GS does not pull like the Formula. Hard to say because they are the only two nice cars I've had, but the GS, which is a nice ride and respectably quick, was no formula 350, at least in my case.

 

Okay, GTP's "should" be in the high 14's. Freaks have hit 14.1's and 14.0's. 1 person claimed to hit 13.9, but never posted a time slip, so let's just say low 14's is it. As for power, they put down 195whp and 267wtq.

Not as much power as a 350tpi, but their redline is at 5800 vs. 4500. I had a GTP with a smaller pulley, fenderwell intake, 3" dp and a 2.5" cutout and I hit a 13.93 while missing 3rd gear ( manually shifting) could've been a 13.6 for just under $350. Can't say that can happen with a TPI car. Eventhough, an Fbody is 100 times more fun to drive than a GTP.

As for the people who are confusing Grand Prix models here's a brief desription.

TGP: 1989-1991 Turbo 3.1 205hp Just a chip will hit high 13's
GTP: 1992-1996 3.4 quad cam 205-215hp <---Only FWD GP with available 5spd. Will hit high 14's if equipped.
GTP: 1997-2004 S/Ced 3.8 240-260hp 3.25 pulley, intake, basic exhaust can hit 13's for cheap.
GXP: 2005-? 5.3 V8 303hp Don't know, I think they are heavy & ugly garbage. Little aftermarket as of right now, won't have the bang for the buck the 3.8sc cars will have.

 

pulley= 50-80 bucks depending on brand i paid 30 shipped for mine.
computer= aver. price is around $200 bucks
i agree on your times mid 14's stock and with less than a 1,000 low 13's are possible. My GTP runs with low 13 second cars all day long and i have $400 in my car in mods. Soon it will be in the 12's after another $400 bucks.

i think you dont understand what these mods do for these cars you are under estimating there. Or maybe your friends are doing the wrong mods at the wrong times and they are not working right.


Thats why you pulled him 40 is a major bog for GTP's. Run one with a reprogrammed pcm from 40 and see what happens.


Do you mean a GXP they have a 5.3L V8

The older GTP's 97-03 you could get the paddle shift too its the comp-G model


2,900 lbs your way off or you have some major weight reduction mods done.

 

I have a 2000 GTP, It ran 15.0 Bone stock! 2 weeks later, I changed to a 3.4 pulley K&N cone filter ($ 150) and ran 13.8 !!!!! Now I run Mid 12's, but have several mods.

Ray

 

i dunno about 13.8. my cousin and his friend had gtps. my cousin had exhaust, intake, and the smallest pulley and he had a best of 14.6. his buddy had even more stuff done and was running 14.3 so it's not as easy as ppl might think. i bet a lot of guys that are running quick times aren't leaking out the real list of mods they have. as far as i know the later model gtps were only good for 15.2 and the newer ones have more power and run high 14's. if you do the math it makes sence. gtps weigh about the same as a f-body and they have as much power as the l98 engines, but lack the rwd. so i would think mid 14's is bullcrap for an older stock gtp. i'd have to see that to believe it.

 

I don't know about the 02 GTPs but the 3.8 S/C in 99 had 260hp. I have a regular GT (200hp) but its still really nice. I wish they had come stick Maybe something to do once the trans am is done

~Matt

 

The 99 GTP had 240 HP not 260 HP......

I have seen Bone Stock GTP's run high 14's.

People that do CAT Back exhaust on GTP's as there 1st Mods , are wasting there money. I have run 12's through the stock CAT Back! The exhaust restriction on GTP's is the Manifolds, Downpipe, and U-Bend.

- specvgini - Your Buddy that had " Intake, Exhaust and the Smallest Pulley". You might want to ASK HIM what size pulley he is running, because I'm willing to Bet he is running a 3.5", or 3.4" with those Mods. Any smaller and he will be replacing his motor very soon. The smallest Pulley is a 2.5".

Ray

 

I test drove a 02 GTP and seriously it didnt pull any harder than my 5.0 TPI.

 

now that i think about it he did say he had a 3.4" pulley. so i guess it wasn't the smallest.. either way those cars have a ton of potential.. how come running a 2.5 would mean your gonna need to replace the motor soon? are there like other areas that need beefing up?

 

It would add to much Boost! I currently run a 3.0 " on the street and a 2.8 at the track w/ race fuel. To run anything smaller you would need supporting Mods... P&Polished Heads, Cam, Headers, Intercooler, etc... Now you don't need all of these to go a little smaller but those are some of the things you need if you were going to run a 3.0 or smaller. Your Buddy could go down to a 3.25 if he added Headers and Rockers. He could expect to run Mid 13's then.

- Wind Charger - A rear drive car will feel as if it were as strong if not stronger then a front driver....

Ray

 

GTP will win by far. Sorry to say it by 305s arent very fast (usually in stock trim), especially an LG4.

 

Ghigman3, please tell me you haven't started your carb-to-TPI conversion yet. It's a very low HP-to-$$ ratio mod. Other mods could offer signifigant gains over what you already have for much less money. Not to mention the carb you have on there now will have a decent powerband once you start removing some of the other restrictions on the engine, as opposed to the TPI system which pretty much has no powerband after ~4500 RPMs or so.

Start with a full exhaust from the engine to the street. Grab some Hooker 2055s or SLP/Hedman equivalent. Also pick up a full 3" exhaust of any kind. I'd recommend Hooker as well for great quality and a reasonable price. Neither the LG4 or the LB9 are going to make good power until you get the exhaust flowing. In fact, you might even lose some power doing the TPI conversion... I believe LB9s came with fact 3" exhaust whereas LG4s came with 2 1/4".

 

Well when my 87 TPI 305 was completely stock my friends 97 GTP raped me and keep on pulling me thats what will happen in this race without a doubt.

Since then he has installed a 3.25 pulley, took out the U bend in his exhaust and got a open air filter. Now he took his car to the track and ran a 13.87 in the 1/4 with just those 3 mods. On a 1/8 mile track he out drove a 351 Saleen once and lost to him all the other times by .1 to .3 sec. So to whom ever said they can't run 13's needs to go do some more research before they make comments.

 

HUH???????????????????????????????????????????????????????????????????????????????????????????????????????????????????
Oh OK Surrrrreeee they did.

 

well it seems that we all at least agree that the 87 iroc won't win.

 

That's why I said "I believe...". I don't actually have an LB9, so I'm assuming that they did since they were the high performance engine before the L98 came along.

If anyone would like to correct me, feel free to do so.

Anyway, I still stand by the fact that carb to TPI conversion is a bad investment either way.

 

TPI sucks. its more of a restriction if anything. thats why i'm ditching it and going carb. i bet just switching to a carb will give better gains then a tpi unit. i believe i read an article on gm performance where a carbed car made like 40whp more than one with a tpi system. I shouldn't say tpi sucks, but its deffinatly not the cheapest and easiest way to make power.

 

Grrr... My wife's piece of crap '96 GP-SE (with the sorry 3100 engine) can pull to forty in first, and sixty-five in second. After that, the lack of low-end torque and sorry transaxle gearing raise their ugly heads and it's bye-bye fun time. The older w-bodies, all hte ones I've seen that can go appreciably fast, have doen the L67 swap, out of the '97-'04 cars.

That should tell you something - boost rocks. However, as far as the looks of the newest iteration is concerned... they suck, in my opinion. I'd much rather shove an L67 into an older late-eigties W-body then drive the newer ones.

Yeah, TPI has limitations, due to the design. Great torque-monster off the line, though, and I found it perfect for street driving. Just one small reason why I'm getting rid of my GTA and devoting my time and energies to the TTA.

 

well if i were you i'd keep your GTA. they are really sweet cars. just switch to a carb setup its much easier and a better design across the power band. check out this little build i have goin. i have a friend who has a bunch of parts and he's gonna sell me an hei distributor, some long tube headers and a 750 carb for 75 bucks. i'm gonna splurge and buy a new rpm performer inatke manifold. that alone should make a huge difference. i can't seem to get my car to run right with this tpi system. i've basically replaced every part of the tpi system.

 

OK, everyone knows the GTP is a tough customer (M62 supercharger, if I remember correctly. Build your F-Body up to beat it in a straight line. Problem, solution...next question...

 

M90 Eaton Supercharger

 

Thanks Capt. Obvious! What's your advice on beating an Indy car?

 

First thing is to buy a real V8 and quit wasting time on a 305