FireSS

Got the car running good but I took it out for a ride and I'm only seeing 3lbs on the gauge. It's a c5 base stock motor and exhaust manifolds with an ls6 intake and stage 1 procharger p1. I've searched the site and found all different boost number for pulleys. Just curious how to tell if it's a boost leak or the pulley is too big.

NVTHIS

That's a pretty big pulley. I was seeing 6lbs on my 4.0 pulley with a p1. I also have a blower cam, longtubes, etc. What's your other mods?

FireSS

Basically stock motor. Just ls6 intake manifold, ported throttle body, 60lb injectors and an axle back b&b exhaust. So your thinking I need a smaller pulley.

youngrigo

You mentioned its a stage 1 kit? So the intake to the blower does not go over the radiator? If so i can see 3lbs with that pulley.

FireSS

Yea stage 1. Im making a leak tester and going to isolate the blower piping to see if I'm losing anything. If that's good then it's the pulley. I was told to start with a 4.5 but everyone has different boost ratings for that pulley. I'm thinking 4.25 would get me to 6psi.

reactor2

I'm running the A&A kit with a 4.25" pulley and I see 6psi. I also have heads (dart pro1), cam (228/232 .571 112), intake (Fast w/ LS2 TB), headers (shorty headers), de-screened MAF w/ nitrous express housing.

My guess is that you may have one of the following:

1) small boost leak
2) unnecessary restriction before the TB
3) bad gauge

FireSS

I'm pretty sure it's not the gauge because I don't feel it pulling. So 3lbs is probably right. And there is definitely restriction with the stage 1 shroud filters. I know there is a small tear in one of the tubes that I'm going repair tomorrow. But I didn't think that would cause a 3lb loss. I still think a smaller pulley is also what I need. I have a 3.85 that came with the blower that I may throw on to give me an idea if it's a leak or pulley.

smokinstorm

I'd put my money on it being a boost leak. We just found a boost leak and picked up 5 PSI and a bunch of power but we're running a more aggressive combo than you.

FireSS

It was a boost leak. There were actually a couple. It was a used kit so it needed a few things repaired. Just took me awhile to find them all. Thanks.

corvet786c

I have a procharger kit D1SC running about 8.5 lbs of boost on a 4.38 pulley. Headers p/p heads and fast 102 thru an automatic forged LS6.