Pontiac Grand Prix Forums : Grandprix

Just curious, looking to do some upgrades to my stock 04 gtp compG...Been reading around and maybe i can get some help on particular brands people have had success with..so far the cheapest upgrades seem to be 180thermo..still indifferent on plugs but the popular seem to be autolite 104s? ive read very mixed things on the intake..custom vs whatever..right now im going for price (lower = better ). I also need to replace my exhaust due to my stupidity..so whats the best kit for that? I would like a nice good sound.

Any suggestions would be helpful! Thanks

__________________
04 Grand Prix GTP CompG, Fusion Orange Metallic, currently all stock

Yup...Either Autolite 104's or NGK TR55's...I'd just get the Autolite 104's

Yup...since you have a '04+ car you can take out the entire stock airbox (don't worry about the PCM as you can leave it where it sits...it won't go anywhere) and bolt a aftermarket air filter to your MAF sensor. VERY Cheap...all it costs is some time and a new cone air filter of your choice. Or you can get a little more creative and run some custom PVC piping in the fender but I am lazy and like the 1st choice and the supercharger is louder that way Plus you'll notice it is a BIT quicker

Well...you picked the wrong platform for a good sounding exhaust...the 3800 don't sound too great IMO...I have the XP Cam, Pacesetter Headers, Catless Downpipe, Stock GM Res. and Custom 3" Piping into Flowmaster 40's...YouTube - GTP Exhaust

The stock catback is not gonna do you any good to replace IMO. I just did it for sound. What I would do if I were you is if you don't want to shell out the money for headers then get a 3" Catless Downpipe from ZZP. Keep the stock catback and replace the mufflers for sound

Then you can think about getting a aftermarket PCM, and drop to a 3.6" Pulley perhaps

Hope this helps ya...

__________________
2003 Blue-Black Metallic GTP Sedan - Almost Done...
2007 Gold Mist Chevrolet Cobalt LT - Custom CAI, NGK V-Power's, Muffler Delete, Custom Tuned PCM...Sure does have every bit of 130 FWHP
http://www.cardomain.com/id/03blueGTP

bluegtp91, the worst 3800s I've heard are catless 3800s. There's so little flow difference from cat'd to catless, I'd put one on just for the better sound.

__________________
2004 Impala LS - got some mods sold!!!
2009 Subaru Impreza WRX STI

NAIOA moderator Still Imp'n, just in a different Imp.

i backed into the concrete blocks on the side of my driveway, and dented the pass muffler and in doing that the whole exhaust actually got pushed forward like 3", its some what fixed but the ubend is fubared so i gotta replace the whole thing anyway. i like the stock sound at idle...i just dunno which mufflers to go with for the deeper sound.

do you have to get a new pcm if dropping to 3.6pulley? its prolly recommended anyway just for all the tuning tho isnt it? which pcm is the best for the 04s?

(Just trying to knock some cheap upgrades out of the way before takin it to the drag strip )

__________________
04 Grand Prix GTP CompG, Fusion Orange Metallic, currently all stock

Well between the catless vs. resonator-less 3800's I'd say a catless one sounds TONS better than a 3800 without a resonator. Plus I have headers. It makes the tone a bit deeper IMO.

But...to each his own. I love the way my car sounds.

__________________
2003 Blue-Black Metallic GTP Sedan - Almost Done...
2007 Gold Mist Chevrolet Cobalt LT - Custom CAI, NGK V-Power's, Muffler Delete, Custom Tuned PCM...Sure does have every bit of 130 FWHP
http://www.cardomain.com/id/03blueGTP

And I have a cat, no res, and a pair of large Magnaflows and anyone who's been at a meet with me will tell you how nice it sounds. Mufflers are all about tuning the sound, not the other parts of your exhaust.

__________________
2004 Impala LS - got some mods sold!!!
2009 Subaru Impreza WRX STI

NAIOA moderator Still Imp'n, just in a different Imp.

i agree with that. dropping the cat really doesnt do much. gonna make ya not pass emissions and have raspy sound

__________________
2000 GP GTP Black 2 Door ZZP Headers, 1.8 Roller Rockers, 3.4" Pulley, Wizaired CAI, ZZP Stg 1 HV TB, NGK TR6 Plugs, 180* Tstat, Custom Tuning by TUNE TIME PERFORMANCE
Soon to come: AEM Meth Injection (100% Meth), 3.0", N*, PRJ Wires, Smoothflow Idlers, 42# injectors, Racetronix fuel pump, more tuning!

figured as much....gonna keep cat...what mufflers ya recommend? flow 40s or magnaflows?

__________________
04 Grand Prix GTP CompG, Fusion Orange Metallic, currently all stock