I have made a cam & pulley change (GT2-3 & a 3.4"), and the bypass seems to close much sooner than it used to. Only about 35% throttle and the bypass closes and starts to build boost. I did change it so it vents to atmosphere instead of back to the intake side.

Can they go bad or need to be readjusted?

 

That's special I'm having problems with mine too.

I called Procharger and they told me wait check this out..........Take a D cell battery and put it where the bypass would go and clamp it down hard drive it like that keeping an eye on the boost.

By doing so you can check to see if it is your bypass he said just be careful and not go overboard with driving it around.

 

Your bypass valve is likely boost referenced. If it is the smaller pulley and cam are making boost lower in the rpm range and at lower throttle angles. I believe that is why the bypass valve is closing at lower throttle positions. This is a good thing is it not?

I am not sure if your bypass is adjustable or not so I cannot help you there. Did you just vent the bypass to the atmosphere with the current chages or did you do that before? Is the bypass before or after the MAF and how does that affect fueling?

 

Thanks Jim. You are correct...boost referenced. I didn't know if it was normal or not, and if I needed to change it for a BOV or something like that. I can't see anything that can adjust it. Everything is before the MAF.

 

2lug-
my problem isn't that it isn't building boost, because it is. It just now builds it at 30-35% throttle when it used to take 70%.

 

How is does it fill since you put the GT2-3 in there, does it have lot more down low??

 

yes & no. I am still running the tune for a TR224 112LSA in there, so it isn't optimal. I was going to get a retune tonight, but the track is closed for IHRA competition. One problem is traction. I am putting 305's on the back to gain some help.

It was running lean (13.5 + AFR) above 5,000 rpms, so I haven't really dogged it lately until the new injectors were in. I don't want to run meth.

I just installed 60 lb injectors last weekend, so hopefully in the next couple weeks I can get the dyno tune complete and a few 1320' passes too!

 

You get my voicemail SC?

 

No. If I did I was drunk & don't remember listening to it!

 

So basically how do fix the problem overall?

Maybe im not getting it does it have something to do with the Procharger bypass nut on top of it do you have to loosen it up a bit?