1998 Grand Prix GTP Bolt-on Upgrades

My buddy has a 1998 Grand Prix 2 Door GTP. I'm very familiar with mustangs but not his car. What are some proven bolt-ons that would wake his car up. Does it have a roots blower in which he could put a smaller blower pulley on? Does K&N's FIPK do anything significant? Any other recommended mods?

thanks

-wade

Well there are some mods you can do without tearing the engine appart. You can install a Trasher CAI(Cold Air Induction) kit(Has the K&N 9" cone filter). YOu can install a 3.2" or 3"(I do not remember the number exactly but you will see it on http://www.3800performance.com or http://www.zzp.com or http://www.pfyc.com). You can get rid of the U-Bend(Nice Article about the restriction on the intake and exahust at http://www.zzp.com). All these should add to the car at least ~25hp if the car has the Fuel Pump, Ignition Coils, Spark Plugs, Injectors in decent condition... If you add a DHP V1.0 Modified ECU(PCM) you can add an extra ~20hp. So if the car stock is 240hp. You can put at least ~285hp at the crank without tearing the engine apart.
Then of you want to get more you can install a 3.29 gear ratio transaxle(diferential) and a Phase 2 Cam(I saw it on the http://www.pfyc.com site)(These 2 mods which are not exactly Bolt Ons but would take the car above ~300hp at the crank).
Pretty decen for a front wheel drive and as you can see they are not really that hard to make...

a 3.4" pulley will give around 25-30 hp. going smaller than 3.25" will give too much KR and will result in possible loss of power--more mods will have to be done to lower the engine and incoming air temps. an intercooler will give an incredible amount of power but will require removing the supercharger and costs about 1200$. www.intense-racing.com will have many awesome upgrades for the 3800 and transaxle. Scott Cook from intense racing also has the quickest front drive late model gp in the world. 670+hp and does the quarter in [email protected] video of it racing is on the website. these people know everything about 97up gps

thanks for the input guys

-wade

Ripn12s, that is an interesting list.

These guys are exactly right. The easiest mods are freeing up the airflow. CAI, new downpipe/cat combo and cat back system. Smaller pulley is an easy boost. Get a modular pulley system in case you want to do additional mods later, and go no smaller than 3.4". If you had all the parts, you could do the everything in one days work.

sgt 007:
I got the 3.4" for standard driving and a 3.0" trasher for track days. I was told that the reprogramming on the PCM(ECU) would take care of the smaller pulley for track days and the CAI also would help on that. What you think about this?

I think you will see massive KR when using the 3.0 pulley.

You need to get a scan tool or some sort - Autotap or LS1M

Go to the track and run that car. Try both pullies, bet you pull worse times w/ the 3.0

Just some friendly advice, dont want to see this turn into another 3 page thread about your mods and who believes you

Thanks for the advice. I do not really care who beleives or not. What I care is that people that knows what I am talking about answer intelligently my questions. Tell me then what should I have in order to be able to reap benefits from the smaller pulley?

Ripn12s, and let me tell you. With the postings on http://www.zzperformance.com, http://www.intense-racing.com among others. There is a lot of documented simple bolt ons that will take the car well above the ~300hp. And that is not me saying it(you know about this, you are verse on this kind of sites) just a bunch of mods. These are simple bolt ons but thanks anyway. Tell me what I am supposed to have in order to reduce the kr effect with the smaller pulley. MOre gas? Lower temp thermostat? Tell me

You've seen my mod list.

I run a 3.1 as a daily driver pulley. I still see 3 deg's of KR

When at the track I run 104 octane fuel and see 0 degs of KR

From what I remember about your mod list you need to throw some more $$$ into the car before you can run that pulley. Best thing I think would be an intercooler.

Do yourself a favor and get a scan tool. That way you can actually see what the engine is doing and not have to guess.

Check this one out. Its cheaper then the atap and will do the same thing.

http://users3.ev1.net/~chauvin555/LS1M/default.htm

Is pretty neat. Good use for my PalmVx.
But the DSB9 connector won't fit on the car PCM jack. Do you have any sites for the intercooler? I just got the Trasher CAI. Does that help?

ZZP's intercooler

http://www.zzperformance.com/zzp/products/intercooler.htm

MAP's Intercooler

http://www.3800performance.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=3800P&Product_Code=MAP-IC-SYSTEM&Category_Code=EC

Thrasher's Intercooler

http://www.thrashercharged.com/store_htm/intercooler-fuel_group.shtm

Since I got all trasher stuff this would be the natural choice. Question Wouldn't it raise too much the SC?

Doesnt matter, any of those intercoolers will work.

The Thrasher raises the blower the most out of the 3. It will fit with a stock hood, and some modifiction on some aftermarket hoods. The thrasher is also the most expensive.

Like I said, get a scan tool and then go from there.

Tim

Its Not Trasher!

Its Thrasher!!!!

GTP Catz, thanks. What is important is that I was understood. For your sake then Thrasher(Trasher is not that bad taking into consideration is a shorter word and could mean trashing competition, LOL ;))

TIM, I just checked the order they made on 9/19/03. The pulleys they ordered are 3.4" and 2.8" from thrasher(:) GTP Catz). I already sent a note to Chavin to see if the cables he has work with my PalmVx. I am pretty sure that with 93 Octane(Available here) and the Octane Boost that I add every tank full the K&R is 0 or really close to 0 with the 3.4" pulley. Now the tests I am going to make are the K&R with TCS on, TCS off, same for both pulleys and will let you know.

Tim, another question. In the mean time, if a 180 or 160 thermostat is installed, with the coldest spark plugs possible and DHP or similar ECU(PCM) is installed. Would not it help to reduce the K&R with increased SC flow? Just a tought!

Colder plugs and tstat will help eliminate some KR.
Try a set of Autolite 104 they are 2 heat ranges colder then the stock plug, use a gap of .55

These 2 things will not increase SC flow, only thing that will affect that would be smaller pulley, better flowing intake, ported blower housing, exhaust.

I doubt you'll see 0kr with the 3.4 pulley. I dont think that octane booster is doing anything either, that stuff has been proven to only boost octane by 1 or too at best. Do a search on clubgp about stuff called Turlean/Torlen (not sure if thats spelled right)

TCS is not going to affect KR. You'll see KR all throughout a 0-WOT run.

I know about the SC flow. I already drive the car with the 3.4" on a daily basis. Already paid Mr. Chavin, as soon as I get the cable and program will try that on the car to check the K&R. I will check with the guy that moded the car at the dealer to see exactly what Tstat was installed and if the PCM is aware of this. If it is a 180 then I will ask him if he can lower the PCM(ECU) tstat rating and will install the colder plugs if indeed IC K&R when Mr. Chavins kit arrives. Is the K&R will show up idling or under load?

KR (Knock Retard) will not show up at idle only under load.

Usually on the mid to higher RPM's and on the shifts.

Isn't supposed to be normal to have K&R on shifts?

It's normal to have KR but the goal is to get it as low as possible 0

The more KR the car see the less timing you'll have and the less HP you'll produce

Ok, now that we are at this poing. I feel that my car after reached the OD the K&R is really close to 0. Pulls really strong, I will certify that with Chavins cable. Now what you think is acceptable? The 3 deg you have on a daily basis or less?

3kr on a daily basis

After you've reached OD your getting further out of the powerband and the car will stop gaining sooner or later. You want to make as much power through the gears as possible.

This goes along w/ your love for high speed racing. It doesnt matter how fast your top speed is, it matters how fast you get to the top speed. Who cares if you can go 135 mile per hour if it takes you forever to get there.

Got it. As soon as I get the cables and I install the Thrasher CAI and Ubend removal will do the tests. The CAI will reach here before the LS1 cables. So I will be ready for that.
And you are correct, does not make sense to have a top speed of 155 if will take you fore ever to get there. That is not my case but I see your point tought