I just installed my Hallman mbc on my gst. All stock I was at 15psi. Installed the ,bc like this Best way to install a MBC - DSM Forums And there is no change at all.... Also, another reason I wanted to install it was to get rid of the boost fluctuate in higher gears. ie 15-12-15-12 it will do this till you let go of the throttle. Will a mbc help this?

 

this is a long shot but, we had the same problem on a car and it turned out there was a little rubber piece on the boost controller that you have to take out....

 

IDK - Its a used mbc...

 

I take it you disabled the boost control solenoid?

If so, and you have it hooked up right, then turn the knob to the right and it should go up...lol.

What turbo is this? if its a t25 not being able to hold full boost till redline makes sense...although 15psi is not that high..

 

I ya the bcs is still connected to the plug for the cel.

Its a T25, It will not go lower than 12-15psi... Thats the issue.

 

Wait, so you want less boost? A boost controller won't help you do that. 15psi should be fine for the t25 on stock fuel ... I run a 14b at 17psi spike to 15lbs on stock fuel with no problems.

As far as consistent boost, you may try a boost leak test, and if you haven't changed the stock plastic bypass valve (bov) that might help as well...

 

If it a t-25 and you still have that plastic bypass valve, you probably willl not ever stay at 15 PSI. Go to home depot and build a cheap pressure tester with some abs or pvc pipe. Try a different pressure source, im pretty sure I didn't run mine off the compressor housing or j-pipe

 

Ok, I'll be trying that tomorrow.

 

1g bov...15 bux