little extra HP for a n00b

[MrPockets]

I'm sporting a '98 Grand Prix GT and know little to nothing about my auto machanics. From what ive been reading, aftermarket chips are an easy and reasonably cost effeciant way to get a little extra HP out of your car. Could someone please suggust a few quality chips for my car, aswell as letting me know if my impression of said chips is anywhere near accurate. thank you.

[BNaylor]

Unlike older cars (pre 97) you do not replace the ECU chip but get a re-programed PCM module. The PCM module is located in the air box assembly. Companies like DHP, Intense and ZZP have them and the cost has dropped to well below $100. A DHP PCM may give a 8 -12 hp increase by itself on a GT but you must use premium grade fuel. Basically it opens up the doorway to do other mods like intake and exhaust.

[MrPockets]

Splendid. So a custom chip will not give me a considerable performance boost just in itself, but is a good way to start building the engine up, correct?

[BNaylor]

Originally Posted by MrPockets

Splendid. So a custom chip will not give me a considerable performance boost just in itself, but is a good way to start building the engine up, correct?

That is correct. The PCM upgrade by itself it is nothing significant on a L36 but it does lay the ground work for other mods. Can't go wrong with it.

[99.P.GP-GT]

Hi, I have a 99 GT and am just as much a noob, but would be interested in several upgrades, is it still the PCM I would change on my model, is it also L36? and if I wanted to go further, what upgrades would you recommend I do next, its stock right now, thank you

[BNaylor]

Originally Posted by 99.P.GP-GT

Hi, I have a 99 GT and am just as much a noob, but would be interested in several upgrades, is it still the PCM I would change on my model, is it also L36? and if I wanted to go further, what upgrades would you recommend I do next, its stock right now, thank you

Yes, your GT is a L36. PCM, intake - CAI/FWI, exhaust - hi-flow CAT, ubend delete. Not necessarily in that order. Modding is based on how much money you are willing to spend to get the end result whether more hp, more torque, better ET at the track, faster on the street, etc.

BTW - I would have mentioned CAT Back exhaust but IMO waste of money. Bigger exhaust plumbing like going to 2.5" or 3.0" is beneficial. Stock is 2.25".

[FireFox05]

Hey bnaylor, how much work and money would it take to get a L36 to compete with a stock GTP, and would it be worth it in things like fuel economy? Because I'm stuck between getting a GT or a GTP. Price isn't that big of a deal, the GTP's run around 1500-2500 more than GTs around where I live.

My major concerns are the money I'll have to spend later on, maintinence and fuel costs, that sort of thing. But at the same time, I want the quickness of the GTP.

And a small side issue, After getting all the supporting mods, do you think adding the I/C to the GTP would allow you to run regular grade fuel? Or am I pretty much just stuck with the premium if I get a GTP? Thanks for replying and I don't intend to hijack the thread.

[99.P.GP-GT]

thanks for the tips, don't kno exactly what all of them are but i'll look into it, what about a supercharger, i saw someone on clupgp had the second fastest 1/4 time with a 97 gt supercharged plus a couple other mods, that would be sweet to shoot for a setup like that as it seems successful, thanks

[BNaylor]

Originally Posted by 99.P.GP-GT

thanks for the tips, don't kno exactly what all of them are but i'll look into it, what about a supercharger, i saw someone on clupgp had the second fastest 1/4 time with a 97 gt supercharged plus a couple other mods, that would be sweet to shoot for a setup like that as it seems successful, thanks

The tips suggested are just a start and will not lead to a 9-10 second ET. Supercharger is a possibility on a GT but expensive and a lot of work. ZZPerformance has a M90 SS supercharger kit that will keep the cost of the conversion down. And don't let anyone kid you. Extensive for the strip are not necessarily good for the street. These guys, especially at ClubGP do not tell you about all the problems you may encounter or get or how much they really spent to get the end product.

Here is a link from GTPDad to all members on a L36/L67 supercharger swap.

http://www.automotiveforums.com/vbul...d.php?t=368587

The fastest Grand Prixs are twin turbo with alot of mods, more than meets the eyes.

[99.P.GP-GT]

so if i'm going to try and get it twin turboed it would be better on a gt since i am not losing out on the supercharger with the gtp, or do they keep both on the gtp, or is it still worth it to take out the supercharger with the rest of the gtp engine?
thanks

[BNaylor]

Originally Posted by FireFox05

Hey bnaylor, how much work and money would it take to get a L36 to compete with a stock GTP, and would it be worth it in things like fuel economy? Because I'm stuck between getting a GT or a GTP. Price isn't that big of a deal, the GTP's run around 1500-2500 more than GTs around where I live.

My major concerns are the money I'll have to spend later on, maintinence and fuel costs, that sort of thing. But at the same time, I want the quickness of the GTP.

And a small side issue, After getting all the supporting mods, do you think adding the I/C to the GTP would allow you to run regular grade fuel? Or am I pretty much just stuck with the premium if I get a GTP? Thanks for replying and I don't intend to hijack the thread.

There is nothing wrong with getting a GT and then modifying it but I would highly recommend getting a GTP in good shape. Much easier to mod and keep streetable at a lesser cost. We see alot of posts from GT owners and in the end the general concensus is they would have been better off starting with a GTP.

You will be stuck with premium on a GTP. GM specifies 91 octane or better. But to get around the cost factor of gas there are steps to take to run possibly mid-grade. This is applicable to stock only. Once you mod a GTP especially with a smaller supercharger pulley and other mods you will need premium or better. Knock retard is a major factor. It must be kept down or performance goes to pot.

For example even a GT with a DHP or ZZP PCM is supposed to run premium gas. Maintenance on a GT can run as high as a GTP or vice versa. Various factors to weigh. The main advantage to a GTP are the extensive readily available mods. Again, it depends on how much money you are willing to spend.

BTW - No one I know with an intercooler runs less than premium gas. I use VP C10 race gas at the track and that is without IC.

[99.P.GP-GT]

alright thats some good info
thing is my old car died and i got this gt for 4k
i think it was a good deal, there was no gtp available

hearing all that i would be willing to try it, and the gas doesnt bother me
i would probably get 91 and since cali has some sh*tty gas i was thinking of adding that performance additive to up the octane or whatever

now i just wanted to double check, if i want to add a twin turbo and ic i might as well start from my gt since i dont lose out on the supercharger, or is it pretty much a waste to do it on this gt?

thanks

[MrPockets]

Originally Posted by bnaylor

Yes, your GT is a L36. PCM, intake - CAI/FWI.

so the stock GT alreasy has a Cold Air Intake. Is this different then a stage III CAI, and if so, how much would modding it with a stageIII CAI effect its preformance?

[BNaylor]

Originally Posted by MrPockets

so the stock GT alreasy has a Cold Air Intake. Is this different then a stage III CAI, and if so, how much would modding it with a stageIII CAI effect its preformance?

No, stock is just a regular air box. I was recommending getting one as a basic simple bolt-on mod. The best CAIs are the ones that draw air from the inner fender or high pressure area behind the left headlamp. Cold air intakes help but there is no significant hp increase.

[FireFox05]

While on the subject of air intakes, what do you think of the SD hoods ram air box?

Hood
Bottom picture is the ram air option