Procharger late boost?

[ProStang01]

I've been all over the boards, on the phone and just stumped on the performance of my car.

Issue I'm having is my procharger will not make ANY boost until I hit about 4K rpm (less then 5lbs) in any gear. And then I have to hit about 6k-6200K rpm to make 8lbs. I'm told I should see boost starting at 2300K - 2500K rpm.

I pulled my vacuum off the bypass valve and it is sucking in air. I hooked it up the bypass valve and the valve closes. I've also pulled the vacuum line back off, plugged the nipple on the bypass valve, and pushed the linkage down on the valve and it springs back on it's own. Not sure if that means the valve/diaphragm is bad...

I'm running a 4.13" pulley which I was recently told is too big. So I'm getting ready to order a 3.4". Not sure if this will make a difference.

All hoses and tubes seemed to be connected. Any help would be appreciated!

Thanks!

2007 GT/CS
P-1SC-1 w/ 4.13" Stage II
39lb blue body injectors
Diablosport mafia programmer
Kooks longtubes, X pipe, flowmaster catback

 

[ProStang01]

Also it makes more of a fluttering sound when I let off at wot instead of a whoosh. If that makes a difference..

 

[encasedmetal]

sounds like the valve to me. and yes you should be making boost earlier than you are, but also realize your exhaust setup will make a boost difference as well

 

[JP_Stang]

sounds like the valve to me. and yes you should be making boost earlier than you are, but also realize your exhaust setup will make a boost difference as well

^^^This. The fact that you hear fluttering sounds like you are getting compressor surge. I also believe it is your valve. Make sure you have no leaks anywhere too.

 

[Black*Death]

By bypass valve went bad as well.

Valve was in for about 25K. Could not get over 3 pounds. I could hear air escaping at WOT when it was suppossed to be closed.

By Tuner told me Procharger had their valves redesigned due to failures. I got a newly designed one. It is bigger and heavier than my old failed one. No issues after 4-5K miles on it

 

[ProStang01]

Great! I've been getting different answers from people and just couldn't narrow it down... I was thinking about just ordering a new diaghram from procharger and fixing my black proflo valve just because it would be a cheap fix.

If I were to change any recommendations on a bypass valve i can just swap out with my proflo?

Thanks again!

Black*Death I will look into that.