After owning my 99 GTP for 6 years now I have learned of quite a few self mods that cost nothing or close to it! when I got my GTP I started researching and getting to know the car. I've owned 93 cars now and have done some sort of self mod to all of them. Some of these mods may be in your best interest some may not depending on what you have done and what you plan on doing to yours. My car was bone stock, I an the 3rd owner and the car had low miles and was well maintained and ran strong so I figured it was worthy of building. (All the cars I built before were V8"s mostly firbirds, camaro's & even a few mustangs in the beginning. Anyways after countless hours of research here's what I found to work & tested.
EXHAUST.
Cut from cat to behind silencer off and welded in one straight exhaust pipe from down pipe back to mufflers. No more cat, no u bend, no silencer.
INTAKE.
I removed factory air box & piping up to throttle body, removed throttle body screen then put a section of either 3 or 4 inch pvc pipe(been so long can"t remember but if you measure the rubber on the out side of the throttle body its that size, fits right over it nice & snug) & wrapped it with 1 inch thick foil backed insulation and cut it to the right length to where it fit just into the fender well then added a pvc adapter that went from that size to one sive bigger then put metal(not plastic) window screen over it nice and tight with a large hose clamp. The reason I put the larger adapter on the end is because the screen takes up some of the area of the pipe opening so the larger the pipe the more air can flow. I then used foil hvac tape to seal off the fender from the engine bay so no heat could get into the fender, I also relocated the air intake temperature sensor (AIT) in the fender well at end of pipe AND NO YOU DON'T NEED A $25 AIT RELOCATION HARNESS, JUST 18-24 INCHES OF THE SAME SIZE WIRE AND CUT THE AIT WIRE AND SPLICE IN THE NEW SECTION OF WIRE AND RELOCATE THE SENSOR, YOU CAN PUT WIRE LOOM AROUND THE WIRE IF YOU WANT. This pvc intake makes the air have a straight shot from the fender well to the throttle body, no bends or restrictions and if you remove the throttle body screen, insulate the pvc pipe and seal the fender off from the engine bay and relocate the ait it will give the supercharger not only cooler air, and more air but will let the pcm know it and it has been dyno tested and proved to outflow ANY cold air intake or box on the market. I know it sounds a little ghetto but it works and even looks better if you use the chrome foil backed insulation on the pvc pipe.
MISCELLANEOUS.
I REMOVED THE PLASTIC COVER FROM THE S/C BECAUSE IT HAS AN INCH OF FOAM ON THE BACK OF IT AND JUST KEEPS THE S/C FROM DISSIPATING HEAT THEREFOR MAKING IT HOTTER. I also removed the pad from the bottom side of the hood for the same reason, let that heat out , why keep your s/c insulated. I had some black header wrap left over from my last LT1 Firebird I built so I covered the stock manifolds and put two layers of header wrap on the crossover pipe right where it runs under the throttle body. I also made a thick heat heat deflector to go in between the throttle body and cross over pipe to keep T/B cooler.Installed 180 degree thermostat, auto lite 104 plugs, 8 mm plug wires, bought a used 3.4 pulley but didn't know at the time I needed a $65 special pulley puller to change it so I still haven't done that. I switched the front 225/60/16 tires with the front 245/50/16 tires of a Fire bird Formula. Better traction for the GTP less resistance for the bird. Made a huge difference would strongly recommend to anyone running 225/60/16' to swap them out and mount 245/50/16's. Instead of spinning like crazy I can give it about 75% pedal for a second then put it to the floor and no spinning (on dry pavement). In case there's any one who doesn't know this if you have a tcs button (traction control) by your information gauge you have to turn it off every time you start the car to get full boost because with the traction control on it wont let you achieve full boost even if the tires aren't spinning. I think it only lets you boost to either 4 or 5 psi instead of 8 or whatever your pushing. I know most of you allready know most of this but if I can give one person one idea that would make it worth it to me.
DO IT YOUR SELF.
If anyone has any other cheap or free mods i didn't mention I would be grateful to know of them. Right now all of my money is tied up into expanding my body/paint shop. If anyone lives in central ohio and needs any work done or just a buff & detail let me know. I'm certified in everything you can be certified in paint & body wise and have over 10 years experience and will give you a 25% discount just for owning a GTP !
So far I have less than $200 in my car and it runs 14.10"s. Once I get the pulley on I'm guessing I'll get into the 13's. Not bad considering it ran 15.43 when I got it.
My name is John, my email address is jdubb6624@yahoo.com
Anyone with any questions, info, parts for sale or in need of any body, paint, custom paint, or detailing work done please let me know. Thanks.
