I installed my profecB (specII) this weekend, and I'm kinda bummed. My transition occurs late (which I'm 99% sure is because I'm at 7000ft), and with my needle-valve boost control my primary boost falls off from about 10psi to 6psi between 4500rpm and 5500rpm (at which point transition occurs). I was hoping the profec would hold boost steady, but it seems to be an open loop controller, just like the stock boost control. I just assumed that for $300 it'd be a closed loop controller. Guess I should have read more. There doesn't seem to be anything you can do with this controller that you can't do with needle-valves; it's just more convenient with a profec. Nice to have hi/low too I guess.

On the other hand, boost does seem to build much quicker than with the needle-valve, especially in 4th gear. Could be just my imagination though.

Anyway, just wanted to share .

 

it doesnt sound like a problem that can be fixed by the profec B. and the altitude shouldnt matter either.

Id start checking the vacuum system.

 

my avcr, thus far, has cleared up all problems I had prior. Even with the unit off I run 7-5-7, which you are supposed to with the unit off. Takes a lot of tweeking and I still haven't gotten my secondary right yet, but the primary is boosting perfect and solid.

 

There is a few different setups used when hooking up at profec b to the sequential system, from what I have read in the past. The one I found the best was to let the profec b control the waste gate alone, without the use of the factory solenoid. I also placed a needle valve in the pre-control line and adjusted both the profec b and pre-control until I got my desired boost response. It takes a little while to get it right. I have since switched over to non-sequential due to never ending sequential problems, and my profec b controls boost perfectly with no spiking, or creep.

 

That's exactly how I have mine hooked up. No amount of fiddling with the pre-control valve helped.

Engberg: How is yours hooked up? Just to the wg or is it T'd into the pc also? (glad you got yours working by the way )

 

Mine has the wastegate and precontrol T'd together. My secondary is still being lame, I hope it isn't fried (oh well, have a warranty on those bad boys anyways)

 

Interesting...maybe I'll hook it to the precontrol as well and try that. Good luck.