Just got my car dyno tuned but I'm having some issues with my Greddy Profec B Spec 2 boost controler. I have the hi boost set to 16psi and on the dyno, boost would not stay consistent to redline. It kept fluctuating between 15 to 16 psi.. thus causing a wavey graph from 7000 rpm to 8700 rpm. My tuner told me to mess with the "gain" settings to get the boost to stay consistent. So my question is, without having to smash back and forth on the street, can anyone give me some tips as to what their settings are for their greddy profec b spec 2 boost controller?

I'm also having issues when I'm driving on the street at the "hi" setting. It starts to sputter/hit boost cut right around 5500. It didn't happen on the dyno, but only when driving on the street. Do you guys think it's the "gain" that needs to be adjusted as well? I checked the "peak boost" and it showed 17.4psi.. while my boost cut is set at 18psi via Crome. Any input/suggestions would be greatly appreciated. Btw, here's the dyno chart:

 

jon just throw a 15lb or desireable spring in there keep it simple

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDM_Risa &raquo;</TD></TR><TR><TD CLASS="quote">jon just throw a 15lb or desireable spring in there keep it simple </TD></TR></TABLE>

i know, i shoulda just did that instead!

 

bump for some help!

 

My profec did the same crap no matter what the gain setting. Boosting 17psi with high frequency fluctuations between 16 and 17psi. I now control boost through neptune instead

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">My profec did the same crap no matter what the gain setting. Boosting 17psi with high frequency fluctuations between 16 and 17psi. I now control boost through neptune instead </TD></TR></TABLE>

=/

I think i got the settings right.. i gotta do some more pulls and see if i can get the gain to dial in so that i can get the spool to be a bit earlier

 

When we had one, it would spike a psi higher than the target level and then do a slow decay as it climbed to the rev limiter.

 

often spikes can be fixed by lowering the set gain

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">often spikes can be fixed by lowering the set gain</TD></TR></TABLE>

 

bump for some more user input

 

switch to neptune and use pwm control

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">switch to neptune and use pwm control </TD></TR></TABLE>

that'll cost me more money in the end though

 

I think its worth it...you get a lot more than just the boost control

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">I think its worth it...you get a lot more than just the boost control </TD></TR></TABLE>

true.. but i'll just stick with my crome pro and try to figure this boost controller out

 

gain 15-20%
set gain 13lbs

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GodFather of Boost &raquo;</TD></TR><TR><TD CLASS="quote">gain 15-20%
set gain 13lbs</TD></TR></TABLE>

more info on ur set up? is it comparable to mine?

 

Its not my setup that is what i recomend you set it to. I use those units often.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GodFather of Boost &raquo;</TD></TR><TR><TD CLASS="quote">Its not my setup that is what i recomend you set it to. I use those units often.</TD></TR></TABLE>

thanks.. i'll give it a shot and work from there.

 

i would listen to your tuner, he sounds like he is on the right track. what i suggest is that you adjust the SET GAIN to 0. Once you are getting the proper amount of boost (16psi) then start adjusting the GAIN until you get the consistency you desire. Only then should you play with the set gain to help with spool. Unfortunately making pulls to redline is probably the only way to do it.

also you "boost cut" issues may be through the controller itself. it has a built in warning and limit feature so make sure they are off if you want crome to handle boost cut.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dpetro1 &raquo;</TD></TR><TR><TD CLASS="quote">i would listen to your tuner, he sounds like he is on the right track. what i suggest is that you adjust the SET GAIN to 0. Once you are getting the proper amount of boost (16psi) then start adjusting the GAIN until you get the consistency you desire. Only then should you play with the set gain to help with spool. Unfortunately making pulls to redline is probably the only way to do it.

also you "boost cut" issues may be through the controller itself. it has a built in warning and limit feature so make sure they are off if you want crome to handle boost cut. </TD></TR></TABLE>

thanks. i'll definitely try that. I had a friend who also suggested that the boost cut issue could be the controller itself. I need to take a look at it and make sure the settings on that is correct.