Thread: advice on upgrading a stock '98 gt

a few days ago i recently received a 1998 pontiac grand prix gt which is completely stock. i have been looking into upgrades of all sorts to put in my car. i have approximately $2600 maybe a little more to put into my car over the summer.

by the way the car has the 3.8 liter V6 in it.

i definitely would like to reduce the floatyness of the car in terms of its handling characteristics. it kinda handles like a large sofa right now and i would like to stiffen it up without lowering the car if possible. i would also like so squeeze a few more horsepower out of the car if possible.


- i am thinking of putting a new k&n cone air filter kit in
- new performance exhaust (preferably gm's performance parts exhaust)
- new kyb adjustable struts [front and rear] (with four different settings)
- gm performance parts heavy duty front and rear strut braces and rear trailing arms
- new high performance brake pads
- possible new stainless steel brake lines
- new tires
- possibly new wheels (17 inches)
- whatever else anyone suggests ....

there are a few things i am currently unsure about.

is there any one here who has the kyb adjustable struts and likes them? or has heard good things about them? especially in reducing the body roll and floatyness.

i have been doing some research and calculations and supposedly if i were to go from a 225/60-16 tire to a 225/50-17 tire my spedometer and odometer would be slow by approximately 2.9%. is this true?

secondly, how worried should i be about bending new aluminum rims if i go with the lower profile tire (225/50-17)?

i have heard that a new exhaust system will make the car sound much better, and some of the videos on youtube are pretty convincing. i would like the car to have a nice rumble when i punch the gas but not be too obnoxious when i am on the highway. also i want to spend as little as possible on the exhaust. would it be more economical to just get new mufflers and remove the resonator, or to go with a whole new exhaust system?

i currently have goodyear integrity tires on the car which are awful, and im looking at upgrading those. would switching to a larger rim and smaller tire improve my handling more than just putting a high performance tire on the stock rims?

how much would stainless steel brake lines do? would i feel a difference if i just put those in? what about in addition to some nice pads?

in terms of brake pads, tire rack reccomends ceramic pads but should i go with a composite pad which has more stopping power?


any other suggestions or information that would help me would be greatly appreciated. thanks you for your advice in advance - Matt.

just for reference the car has around 25,500 miles on it.

Stay away from the K&N intakes kit's. They are garbage and everyone feels this way about them.

There are quite a few people that have KYB struts and I have not heard anything bad about them.

Don't worry about bending your rims. Enless you drive like 60 over some pretty big pot holes.

As far as the braking goes every little bit helps. But chances are your not going to notice a BIG difference in pedal feel with the stainless steel brake lines.


I would highly suggest the semi metalic pads that I sell. It's still a low dust pad. But it offers a better bite on the rotors and more stopping power. The ones I sell are manafactured by HAWK and I get them by the box full.

I've sold over 30 set's in the past 3 months and all of my customers have had nothing but good things to say about them. I also now use them on all of my personal vehicles. Semi-metalics are also a lot easier on the rotors.

thanks man, i appreciate it.

anyone else have any advice?

the suspension, wheels, tires, and exhaust i would most likely never change .... even if i were to upgrade to supercharger or do something exotic, like put in a turbo. i see where you are coming from, but being a college student who's strapped for cash, i think im just gonna do what i can right now. is there anything anyone recommends i do first?

im still new to all this ...

whats an HV3 insert, a powerlog, 180* t-stat, PCM, and trans-go shift kit?

thanks man i really appreciate it.

on zz performance's website they also have the L36 upper intake which i can add for 80 bucks, what exactly would that do?

has anyone here had experience with zz's performance bent aluminum exhaust system? what about a new magnaflow cat with it? would that help as well?

can anyone give me some links where i can get those spark plugs, wires, and thermostat?

i cant find the trans-go shift kit anywhere either...

also zz's retune says it kicks in the fans at 185*, so would a new thermostat even be necessary?

thanks guys

thanks a lot man. i wish i could go in your direction with a turbo but my parents would kill me. haha.

We sell the plugs and wires also. We are comming out with 10.4mm TDCRacing plug wires. Yes they will be cheaper. Exact same thing as the PRJ ones. Taylor wire. MSD boots.

guys has anyone had any problems with re-aligning their car especially with the camber in terms of using lowering springs. i read somewhere that someone was having problems with the camber because the car wasn't originally meant to be lowered and some kind of bolt was not long enough or something. has anyone here heard of anything like that? thanks again?