Well, I have read a lot of threads on setting the Profec but I can't get mine to hold peak boost. Here are the settings I have: Set: 50%, Gain: 25%, Set Gain: .70, Warning: .83, Warning L 30%. I have tried a lot of different combonations but I can't get it to hold .80 which is where I want it. Everytime the car boosts it reaches .80~.82 and then falls off to aroud .55 or so. What setting do I need to adjust to get it to hold at peak boost. I started out with the settings from this post: https://www.rx7club.com/forum/showth...t=192249&page=5 They are: for 10 psi....

37-38% duty cycle
0-2% gain
9.5 Set/start boost

Any help you all could give me would be greatly appreciated. Thanks for your time.

 

try this:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/profec-b-spec-ii-definitive-thread-needed-365998/

 

Personally, I think your GAIN is too high. My bet is that you are spiking due to the high GAIN, then going back down.

Try a GAIN of 10%.

The key is to make sure you have stable boost. Set duty cycle for desired boost first. Then adjust SET GAIN (ie boost response). If SET GAIN is too high, then you will also spike. (On my car for 15 psi, my SET GAIN is 11.5, any more and it will spike.)

HERE is an excellent How to Tune the Spec 2 write up.