Thread: KR - 3.4" Pulley

Hello together
I have a 2000 Pontiac Grand Prix GTP since 8.5 years
Mods are done:

GTX hood (Ram air)
MSD cables
Aeroforce gauge
Oil pressure gauge
Amp gauge
Boost gauge
3.4" pulley
U-bend delete
colder thermostat (160F)
colder plugs (NGK TR55)
Front powerlog
rear powerlog
Trush mufflers
Cherry bomb resonator
High velocity throttlebody
Throttlebody spacer
Chrome valve covers
Intense PCM
Got a question:
If I drive normally I have 0.00 KR. If I pusch the throttle half way ist 0.00 also
If I push it really hard to the floor I have about 2-6 KR
Is this normal? Or should I change back to a 3. pulley?

Thanks for your answers

was the tune for your car? or did you buy a used pcm off someone?

Go back to a stock pulley. You don't have the mods to run a 3.4.

@GTPpower Ok...then tell what do you need for a 3.4 pulley??
I thought this was enough

@scottydoggs was a tune for my car

thats a lot of kr, copper spark plugs can help, dont think 104 copper plugs would help that. some cars just wont take the timing in a canned tune. any idea what they set the timing to?

as far as mods go, you got the basic intro set up. you could add rockers, they help things flow and kill kr, pulley back up to stock, see if it still has kr wot.

then theres intercoolers, they tend to let you run a smaller pulley and more timing due to the porting. im intercooled with a 2.8 pulley rockers, ported heads, and meth, making about 12 psi boost, i used to make that on the 3.4 pulley back in the day.

or a meth kit, but meth you need a tuner in hand to adjust the maf for it.

if you have the pulley puller still. pop the stock pulley back on, see if it still got kr or not. if no, leave it on there. it will run stronger regardless of the pulley due to no kr. every degree of kr pulls 2 degrees of timing, so lets say your set to 18º wot timing and get 6º kr, thats 12º being pulled, so now your running on 6º timing and it falls on its face.

cause you dont start to make over 7-8 psi till about 4500 rpm, then it knocks cause its more then it can handle.

your making 10-12 psi now vs stock was 7-8. so you either need to lower the timing, (you need a tuner for this) or pulley up back to stock.

you can also try scanning your o2 sensor. if its not reading in the 900 + range wot its time to replace that, bad o2 can cause kr. been there done that, no codes either.

Question... how many miles are on the valve train?

Originally Posted by kappa67

@GTPpower Ok...then tell what do you need for a 3.4 pulley??
I thought this was enough

@scottydoggs was a tune for my car

Switching to e85 is the easiest. Other than that, you can intercool it or add meth injection. Or a cam, if you want to dig a little deeper

All canned tunes suck. You're probably better off with stock.