Thread: gotta make her faster this spring

I'm in the same boat as you. I need a faster, reliable GTP that doesn't get 15 MPGs. This spring I plan on a 3.4 pulley, headers and a custom tune. That should be a very good start and still be reliable without breaking the 100K+ mile transmission. Modified rockers need new springs and cam is a partial engine tear down. $.02

Okay, lots of questions to answer.

First, reread this. (since you seem to have a decent grasp on things already, I'm assuming you've read it)
http://www.grandprixforums.net/showthread.php?t=67580

Firstly, you don't have to pull the motor to change the cam (I literally swapped cams 2 days ago, took about 10hours from removing the first bolt, to having it done and running)

You don't have to change thermostats, but most people do anyways for the 180* Tstat.

300HP is possible without going into the motor, but you will need an intercooler for that.

Don't give into the stage kit stuff. They usually contain a bunch of stuff you don't need ($200+ intake)

Best deal is to find used stuff on the forums from someone demodding.

The stock trans is decently strong as long as you don't beat this piss out of it, and you take care of it (Trans flush, new filter, etc) There are a couple people putting down good power with s/c or turbo setups with a stock trans.

First thing I would do is make sure all the maintenance is up to date (including the trans)
Then, a set of headers, and a home-made intake. (Just get a 4" cone filter and either put it on the TB, or make your own intake piping)

After that, decide if you want to mod it further. If not, get a canned tune from one of the vendors (I prefer Intense, personally)

If you do decide to mod further, I suggest doing a cam swap, or 1.9 rockers. Then get a custom tune.

As far as gas mileage, my old ported Gen III, 3.4 pulley, headers, intake, canned tune got 22-23mpg city, and 30-32mpg HWY. And currently, my untuned cammed 3.8 pulley Gen V setup is about 19city, 29HWY.

how difficult is it to remove the stock exhaust manifolds? this is nothing i havent done before but my last "hot rod" was a 1989 camaro that i swapped a 350 into. kind of a different deal then a FWD transverse mount v6. how do you remove the cam from a FWD engine without pulling the engine?? that cam is kind of long well its allot longer then the space between the inner fender and the block. i understand all accessories have to come off the engine ect. i built my camaro but that was old school. this is what i did when i was running that car. i pulled a 305 tbi, installed a 350 tbi, installed a bored throttle body, edlebrock TES headers, swapped PROM chips (bought a chip from tbichips, sent him the specs he burned a chip), changed fuel pump to higher flow pump, installed L89 heads, and a better cam. i had a car that was very steerable and had good power but the gas mileage stunk so i parted ways and bought a GTP. i know these cars will get better fuel economy and close to if not better then the 350 power wise.

i know that the grand prix is not a grand national but it still has the heritage of the 3.8 in its blood, its a history as rich in performance as the good 'ol 350 V8 but its much more fuel efficient

http://www.mccgp.com/upgrades/camins...nstall_new.php

^in car cam install. Hardest part about removing the stock manifolds is dealing with rusty crossover bolts. The day before you plan on pulling them, soak them with PB-Blaster and heat cycle it. Help loosen them up.

Header install should take the better part of a day start to finish for a first timer. Same thing with a cam swap.


I can't say the history is as 'rich' as the 350, because that's the single most prolific motor made.

Our LT1/LT4 95' wagon still gets 21-23mpg on the interstate cruising at 75ish. But that's just a bolt-on car with a stock rear end.

It gets better mileage than the older TPI motors.

And people that turbo the 3800's make some damn good power. 400hp is fairly easily reached.

There is a lot of power to be had doing a turbo build on these motors. Most people end up going with an L26, or F-body upper/lower intake setup for better results.

Hey squid you really should let me tune that thing for ya!

but anyway. Like said cam can be done in car and to hit 300hp a cam really should be in the mod list. I would suggest if you an to keep the car for a while and want to mod to that power level get a tuner and start learning or make friends with a local who has a tuner. If you get your own, it is much easier and more forgiving to learn to tune on a lightly modded car then to wait and risk damaging the engine with a mistake in your tuning. I would start with your Maint first, then tuner and start learning, intake, headers, cam and springs, pulley drop. Too many people jump into dropping pulleys before they have a solid foundation for it. A header cam and properly tuned car with a big pulley will blow a car with a smaller pulley away if it doesn't have the supporting mods and has to drowned itself in fuel so it doesn't go Boom!