2004 Compg Pulley Upgrade

[BLKCOMPG]

Well guys I just installed a new CIA and a SLP catback exhaust and I love the noise that my GP is making now. If the blower kicks on at all there is a awesome whiney noice coming out of my hood now!!!! The little Mustangs don't really even try anymore if a rev it up a little at a stop light. I have a real ? though.... I am wondering what kind of results I will be getting with a pulley upgrade. I don't really want to make my car a racer. I'd like to keep it a daily driver, but I'd like to be able to smoke GT mustangs and other street GP's at the track. I guess I am asking how small, what kind of horsepower improvements w/o causing a lot of knock retard, and will it give me a supercharger whine while I am sitting at idle?

[Ripn12s]

3.4 - w/current mods maybe bump your stock horsepwer by 30-40

My 98 w/ 3.4/catback/ubend delete/airbox dynoed 223 at the wheels w/ over 300 ftlbs of torque

[BNaylor]

IMO the 3.4 is the best street pulley. I understand that the knock retard (KR) on the 04/05 GTP is not as bad as the '97 - '03 due to the Gen5 supercharger and the bigger 75mm throttle body versus 70mm of the old.

At least you don't to worry about a u-bend delete because you don't have one. You'll still need to drop down a range or two colder on the spark plugs. Good luck!

BTW - Don't forget replacing the stock SC drive belt with a GoodYear Gatorback.









Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[BLKCOMPG]

30-40HP!?!??!?!?!!?!!! Wow!!!! I should definetly feel that behind the wheel! I am also wondering if anyone has changed the pulley on there GP w/o changing their PCM, and was there any problems with that? I am definetly going to get the plugs upgraded and the gatorback belt when I install the new pulley. Also, since this car is a daily driver will I be able to run that 3.4 all of the time or am I just going to get to run it every once in a while. My GP only has about 20000 miles on it and I want it last quite a while longer....

[Ripn12s]

Just get the 3.4, the car should have come w/ that size pulleys to start with.

You'll be fine w/ the stock pcm

I waited till i put a tep cam in my car to get a pcm. I have tried both DHP and CYA pcms and think the DHP performs better. Ofcourse the car was on the dyno while dhp tuned it so that probably helps.

[BLKCOMPG]

Sooo........ A pulley upgrade will have a big adverse affect on the reliability and drivability of my GP? Also if my car already comes stock with a 3.4 pulley why would replacing it with the same size pulley give me more HP?

[BNaylor]

The stock SC pulley for '97 - '05 GTP is 3.8.









Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[BLKCOMPG]

So, does anyone know of any negative side effects of using the 3.4 pulley on a daily driver? And I am also wondering how often if ever I should replace the supercharger oil on a GTP w/3.4 pulleys and stock?

[BNaylor]

Originally Posted by BLKCOMPG

So, does anyone know of any negative side effects of using the 3.4 pulley on a daily driver? And I am also wondering how often if ever I should replace the supercharger oil on a GTP w/3.4 pulleys and stock?

Maybe a drop in fuel economy but I used to drive my GTP to work and take trips with a 3.4 SC pulley with no problems. Also, you can get a modular pulley system and swap them out when you really need the better performance.

Not sure about the Gen5 blower but GM recommends servicing the Gen3 blower every 30K miles or so. That's just checking fluid level (refill) and not replacement. However, I change mine out every year just to be safe.








Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[Ripn12s]

Also if my car already comes stock with a 3.4 pulley why would replacing it with the same size pulley give me more HP?

I said "it SHOULD have come with that size pulley stock"

There has to be a few thousand people running 3.4 pullies. You'll be FINE. Should'a saved your self some money and just bought the mufflers though.

and will it give me a supercharger whine while I am sitting at idle?

no. you'll only hear the whine when making boost and you wont be doing that at idle

[BLKCOMPG]

Ok, I'm convinced. The 3.4 pulley will be installed just as soon as they can send it to me! Plugs?!?!?! Will they really make that big of a difference? And, I'm sure after I throw this new pulley on I get used to it and want a little bit more. What next w/o sacrificing reliability? I am running out of ideas.... I am also gettting bored with worrying about reliability!!! I want to buy a nice 98 or so coupe to REALLY play with! Who knows maybe I'll have pic of my GP on here and I will be able to answer some of these questions for people... and maybe play with some of your 13 second 1/4 mile times......... One day.....

[Ripn12s]

If your going to get a car to "really play with" then I wouldnt waste the money on a GP. Pick something that is a v8 and alteast rwd.

As far as what to do next, I would say rockers would be a good choice.

[BLKCOMPG]

Not to many 8 cylinder 4door cars out there that can be such a voilent little sleeper and still have my heated seats and HUD!