I am 98% gung ho about the mods I am about to perform. My concerns are the mileage and driveability. Here are the mods:
Wizaired CAI
SLP headers/downpipe with install kit
Highflow cat from either SLP or Random Tech
Harland Sharp 1.9 roller rockers from Intense
Oil restricted pushrods from intense
3.2 modular pulley from intense
Belt tensioner from intense
U-bend replacement
180 degree thermostat
Autolite 103 sparkplugs
Trans cooler (don't know from who yet)

The only other wild card is the PCM. Don't know what to do about that yet. No DHP yet for the 03. Possible Hypertech programmer solution (still waiting to here back from them if one exists for the GTP).
I was told by Scott from Intense that driveability should feel near stock with these mods until I jump on it and shouldn't throw any codes. I am not sure if I believe him though. I am REALLY wondering what the impact on mileage will be. Can anyone with similar mods give input on these two concerns(driveability and mileage)? Thanks,
Jack

I dont think you can get away with a 3.2 pulley with a stock pcm. Smallest Ive seen people go with is 3.4 on a stock computer. The rockers might give you problems too without programming.

Personally I think without reprogramming the computer to account for all those changes, the car probably wont be running at its full potential, though it should certainly run better.

Im sure someone much more knowledgeable than me will chime in
Jeff

Everything on the list was based around the pulley. The computer is a biggie. I'm still waiting to hear back from Hypertech.

did they say why 03 is left out of the mix? What the hell did they change in the last year?

Jeff

Jack,

How many miles you get out of a decently mod'd GP is going to depened a lot on maintenance. Take really good care of the car and don't push it when you know you shouldn't and it could last a long time for you.

Look at my sig below. I have 183K miles on my car right now and most all of those mods have been on my car since the 95K mark.

Plus... sometimes it's a crap shoot too. How many times have we heard of trannys going south with only 20K miles on them???

Good luck and take care of it,
Marc

I was hoping to get your input Marc. Thanks. But What I'm curious about most is when I'm on the highway. I get 27 mpg at 70-75. Will that figure go north or south and by how much. Of course when I jump on it, all bets are off.

My mpg's have dropped off over the past few 10K miles or so. I believe that's due primarily to the high miles vs. the mods. There was a time, not too long ago, when my car was seeing city/hwy mpg's of 24/32. That's with all the mods in my sig. So, I'd be willing to go on record as saying that mods. don't effect your mpg's until... like you mentioned, you jump on it.

Marc