Boost controller quirkiness?

[nikp]

Ok, taken by profec b spec II back to the beginning to try and get it setup properly.

It\'s getting better, but still a bit \'quirky\'. Basically, i have the set at 12%, gain at 0%, set gain at 0.57.

I\'m running at GT35R turbo. I still seem to be getting slightly higher boosts in the lower gears. Roughly, i hit 0.95 bar peak in second, the 0.85 in third and 0.8 peak in fourth. For a blow off valve as a temporary thing i am running the stock twin turbo re-circ valve. Could this be the issue: could the re-circ valve be bleeding off some of the air in higher gears as it\'s not up to the job?

[nikp]

Oh, and my target boost is 0.85bar, which is why i stopped at those settings, as that\'s what it hit in third gear.

[antnicuk]

i cant remember but moving the gain one way will help reduce boost spike which is what it sounds like you are getting in the lower gears.  Does it get worse if you increase the gain?

[antnicuk]

i don think it will be the recirc valve as you are only running a little more than standard boost.  pressure is pressure what ever turbo you have

[nikp]

i cant remember but moving the gain one way will help reduce boost spike which is what it sounds like you are getting in the lower gears.  Does it get worse if you increase the gain?

Well, I currently have gain set to zero, which in theory should be I can hit a peak boost and then it will drop off - as i should have to increase gain to get more consistent boost at higher rpm.

So, i guess i should lower my SET value, and increase my GAIN a bit. I was also considering lowering the SET GAIN a bit, as i though that that might be assissting it to peak too early.

[rx7veilside]

try theses approx settings
gain 5%
set gain 110
set 43%
warning 150
warning limiter 20%
these were my settings running 1.1 bar so lower the set figure to say 25% and take it from there
as i understand it the set figure is ur max boost so start at 25 maybe and alter to get ur target boost.then alter gain to get smooth boost without any spikes

[antnicuk]

whats the difference between set gain and gain,  i thought gain was how quick the turbo spooled controlled by keeping the wastegate shut longer until the boost had reached the set level as oposed to letting it opening slowly and the turbo spooling slower.  If it comes in too quickly it can spike

[nikp]

set gain is when it opens the wastegate, yeah. gain is what Greddy call it\'s consistency - you basically use that to stop it from either spiking (turn gain down) or stop the boost from dying off at higher revs (raise the gain).

[BlitzBoy]

Confusion on settings here, on my profec the only two settings I fiddle around with is the %Duty (The rate the solenoid opens and shuts and sends signal to the wastegate, this setting increases boost) and %Gain is the time the wastegate stays shut then opens to hit target boost, the higher the gain the longer it stays shut thus increase boost response and lessen the lag downside is boost spiking, so increasing this will improve turbo spool but increases spiking.

My advice is when setting up make sure your gain is at 0 and only increase the Duty value till you hit the desired boost level, then once attained then fiddle with gain to fine tune the boost response.

My settings for 0.8 Bar are 31% Duty and 20% Gain

[nikp]

try theses approx settings
gain 5%
set gain 110
set 43%
warning 150
warning limiter 20%
these were my settings running 1.1 bar so lower the set figure to say 25% and take it from there
as i understand it the set figure is ur max boost so start at 25 maybe and alter to get ur target boost.then alter gain to get smooth boost without any spikes

I\'m only mapped to about 1 bar. I accidently (long story) set the SET to about 30% last night and hit 1.07 bar in third without hitting full revs. So I had to turn the value right down to where i am now.

[nikp]

What strength spring are you using Mark? I\'m currently on 10psi. Wonder whether it\'s worth going down to a 7psi spring?

[BlitzBoy]

10psi spring im using. Defo try putting the "gain" to zero first, it will spool up a lot slower but at least you can set the target boost correctly with the "Duty" setting

[antnicuk]

what size Flange and exhaust A/R do you use?

[nikp]

Me? Or Mark? If me...um, can\'t remember. 1.0 something or other i believe! :p

Gain is already set to zero.

[BlitzBoy]

you sure you set it to 0, your first post says "i have the set at 12%, gain at 0%, set gain at 0.57" so is it 57 percent or 0?