age old exhaust question

[donmega]

I have an 04 GTP. 3.4" pulley, K&N CAI, MSD coil packs, 160 thermostat, reprogrammed pcm, 3" downpipe no cat. Looking to spend about $300 range for an exhaust upgrade. Im looking at mufflers or headers, as a full exhaust kit is about 500. I have stock resonator and mufflers now. Anyone have suggestions for a best option here. None of the o2 sensors are operating bc the PCM upgrade. Im looking for as deep a sound I can get out of a V6. Ive heard crazy things like people cutting off the resonator and mufflers and running straight pipes back. i have access to welding equip also, so sky is kind of the limit. Im open to suggestions....

[CTKGP09]

headers is a must, stock resonator, your choice of mufflers, if any = nice tone

[benner]

Frony O2 senser still operates other wise the engine wouldnt know how to adjust fuel trims, but behind that the choice is urs. I suggest a Dynomax Superflow in place of the resonator backed up by your choice of mufflers.

[donmega]

yea sorry the front bank sensor still reads. She runs rich as hell though

[benner]

Yeah but better than lean as hell.

[donmega]

wheres the best place to look for these parts?

[benner]

Haven't seen any sponsors that offer the individual parts so mods don't crucify me if I say

Summitracing.com or jegs.com

[CTKGP09]

mufflers anywhere

ive posted in a ton of header threads with the links to good headers, just search and look for my posts

but here is a start
http://www.grandprixforums.net/heade...ead-25922.html

[rmil03]

bro, straight pipe after the cat, i just did, its deep

[matt5112]

bro, straight pipe after the cat, i just did, its deep

you literally must have no hearing left.

That is hands down just as bad if not WORSE than your typical straight piped four banger....

[CTKGP09]

its deep, at idle.......and everything else sucks

[blwn3800]

I have an 04 GTP. 3.4" pulley, K&N CAI, MSD coil packs, 160 thermostat, reprogrammed pcm, 3" downpipe no cat. Looking to spend about $300 range for an exhaust upgrade. Im looking at mufflers or headers, as a full exhaust kit is about 500. I have stock resonator and mufflers now. Anyone have suggestions for a best option here. None of the o2 sensors are operating bc the PCM upgrade. Im looking for as deep a sound I can get out of a V6. Ive heard crazy things like people cutting off the resonator and mufflers and running straight pipes back. i have access to welding equip also, so sky is kind of the limit. Im open to suggestions....

Surprised no one has said anything..you have no business running that 3.4 on there. Nowhere NEAR enough mods on that gen V. Do yourself a favor and forget the mufflers and pick up some headers or put the stock pulley back on.

[shawngtp]

Headers = FTW.

[VictorSmalls]

Surprised no one has said anything..you have no business running that 3.4 on there. Nowhere NEAR enough mods on that gen V. Do yourself a favor and forget the mufflers and pick up some headers or put the stock pulley back on.

Agreed, you should be scanning because you are getting knock with that pulley on there.

[GAFF]

Headers, borla xs mufflers, Stock res or cherry bomb in place.

[Reptile]

Surprised no one has said anything..you have no business running that 3.4 on there. Nowhere NEAR enough mods on that gen V. Do yourself a favor and forget the mufflers and pick up some headers or put the stock pulley back on.

I'm kinda with this guy. A 3.4 is a pretty serious upgrade on an 04+ car, and you should be looking to see if there is any KR, because I'm willing to bet there's 4-6* there. I've seen several of those cars that I've had to pull timing on even a stock pulley when they didn't have headers.

[blueguy]

Boom goes the dynamite. 3.4" on a JinnyFive car is header/rocker/intercooler/meth injected/cam territory. Pick a couple of those mods chief...your car will thank you.

[donmega]

I have no business??? lol. ive had no problems with KR. I did at first but since i put the coil packs new NGK plugs and MSD wires it runs smooth through. hooked it up to a scanner. Ill go with headers, and hook it up to a scanner again to double check the kr. thanx fellas

[blueguy]

What kind of scanner? Hmmm?

[blwn3800]

Coils and wires do nothing to combat KR, in fact, you are probably hurting your ignition performance by using those MSD coils on your GTP. I have an 05 compg, xp cammed, headers, FWI, t-stat, blah..blah..blah and i was still seeing 1-3* of KR in the upper RPM's with a 3.4, I am now running E85 and a 3.3 with stock timing tables . Now every car is different, but i can only imagine whats going on with your car, which basically has a down pipe as far as exhaust flow mods are concerned, not good.

Good choice going with the headers

Didnt mean to come across as an arrogant prick, just trying to help you modd the right way Happy modding