3.25 Pulley Help

[s6dark6angel6s]

Hi there folks, im new in this forum.
Im looking for some help in to my 1997 grand prix GTP i have a few modz, PCM reprogram, 3.25 pulley, resently engine overhaul, modded intake, modded SC.

But my problem its that my supercharger only trows 5 psi of the 10 psi, that the 3.25 pulley produces.

Can anyone help me with my problem? i dont know what happened.

Thanks a lot

[QwikGT]

3.25 is too small of a pulley. what is your complete mod list?

[minichopper6hp]

umm yea.... a 3.4 will give you 10 psi lol

[blueguy]

X2 on the mod list...your car is probably slower than a 3.4" or 3.5" pullied car.

You are most likely knocking and that is why you're not boosting right...

[s6dark6angel6s]

X2 on the mod list...your car is probably slower than a 3.4" or 3.5" pullied car.

You are most likely knocking and that is why you're not boosting right...

may I change to a 3.4 or 3.5 pulley?

I read at zzperformance that a 3.25 pulley its good for a stock or sligthly modded GTP

and how i fix the knocking to be usefull the 3.25 pulley

[Sabrewings]

You need a lot more mods to run a 3.25. You're not even safe to run a 3.4.

[DWosik13]

may I change to a 3.4 or 3.5 pulley?

I read at zzperformance that a 3.25 pulley its good for a stock or sligthly modded GTP

and how i fix the knocking to be usefull the 3.25 pulley

you must of misread cause thats def wrong 3.5 is for slightly modded cars

[Sabrewings]

Straight off ZZP:

97-03 Grand Prix & 04+ supercharged Impala & Monte Carlo SS

3.5 pulley totally stock car

3.4 pulley Colder Tstat & spark plugs, downpipe, Cold air intake (still could have KR)

3.3 pulley all of the above plus a VS cam, SS intercooler, or headers

3.2 pulley 3.4 mods and a XP cam

3.0 pulley 3.4 mods and a fullsize intercooler or an SS ic and a VS cam.

Anything smaller than a 3.0 pulley will require a camshaft, headers, intercooler & injectors

[blueguy]

You fix the knock by putting a bigger pulley on. Probably a 3.8"

[05SS45]

wow!! i would put the stock pulley back on asap!

[s6dark6angel6s]

Ok i'll try puting a 3.5, whats the original size of pulley? 3.6?

[blowfishRus6]

3.8

[s6dark6angel6s]

Ok guys, tnks a lot, i will notify you when i make the change and what happened.

[Bio248]

X2 on the mod list...your car is probably slower than a 3.4" or 3.5" pullied car.

You are most likely knocking and that is why you're not boosting right...

how do you not boost "right"? you put the pedal down and it boosts no matter what pulley you have. it just boosts more with a smaller pulley.

if it is leaking off 5 pounds of boost i say your BBV is bad, but i also agree with everyone else that the pulley is too small for your mods. you need a 3.5.

[Sabrewings]

The PCM is probably blowing boost through the bypass solenoid because of how much boost and knock it's seeing.

[Bio248]

...but the PCM doesnt do that...

it limits boost on torque management and traction control...that's it.

[Sabrewings]

It also does it to protect the cat should it detect a condition that excess fuel is being dumped. I'm staring at the table that controls it right now.

[Bio248]

guess ive never ran that rich before..

[s6dark6angel6s]

how do you not boost "right"? you put the pedal down and it boosts no matter what pulley you have. it just boosts more with a smaller pulley.

if it is leaking off 5 pounds of boost i say your BBV is bad, but i also agree with everyone else that the pulley is too small for your mods. you need a 3.5.

And how should i know if the BBV its working fine?

[dagger]

you might be thinking that your not seeing all your boost because your cars not as fast as you'd want it to be. Your best bet would be to get a 3.5" pulley and a scan tool.