Profec B Spec-ii Setup And Tuning (help!)

[Douse]

Yeah I am fairly certain that the SET GAIN is too high which is causing your issue.

Your setup seems correct, I also have a blocked off pipe which appears to be in the same location.

It was blocked when i got my car, so the previous owner in Japan must have had an EBC in it, but removed it.

I am at work atm, so i will have a look in a bit and let you know...

[Spraderz-33]

Cheers man thanks for that. Ill let you know once i have changed it and see if its working correctly. What are your settings and what psi are you running?

[Douse]

From memory these are the following settings for my Profec B Spec 2 on my RB20.

SET = 55%

GAIN = 5%

SET GAIN = 0.53bar (7.687014 psi)

WARN = 0.95bar (13.77861 psi)

LIMITER =15%

I find reving out in high gears it sometimes reaches 1.00 bar (14.5038 psi)

I also find, that it does not reach optimal boost until i am reving at about 4500 to 5000 rpmish. I would like it to reach max boost sooner and hold all the way out through the rev range without creeping to much at high rpm. But the gain is turned down all the way....

Since it has gotten colder i have dropped it down to about 50%ish as it has been hitting 1 bar a bit more frequently

[Spraderz-33]

Haha cant complain about that Ill try your settings and see how i go with it, there shouldn't be too much difference between the settings between the Rb20 and the Rb25? Cheers man

[Douse]

There shouldn't be any difference when it comes to boost levels.

The power will be different of course due to a larger turbo on the RB25, but basic settings should be the same.

If you have a series 1 R33 with a steel compressor wheel it may be a little laggy so increasing the SET GAIN should allow the boost to come on quicker, but once again i am no expert and i have a R32 so i am only going by what i have read

[bubba]

Yes there will be a heap of difference between RB20 and RB25 settings unless you're running an RB20 actuator.

I also wouldn't put your SET GAIN to 5psi, A) it defeats the purpose of this function and B) that is when your stock actuator will be opening and it might create some issues.

Start conservatively with your SET GAIN at say 7psi then slowly bump it up until it starts to spike then back it off slightly.

[nuclear_skyline]

A good way to tune SET GAIN:

1. pick desired boost level (12psi or 120)

2. tune gain to suit

3. SET GAIN to 3psi (30) less then max boost (Therefore 9psi or 90)

4. go for run, and watch the guage, does it spike or not?

a. Spikes: reduce SET GAIN in small increments

b. No Spike: increase SET GAIN in small increments till spike occurs, then go back 1 setting

[Douse]

Hmm i might start increasing the SET GAIN on mine then.....

Maybe thats why it takes a little to reach full boost...

[Spraderz-33]

I might have to give that a go today. Im currently only on 5.5psi for my Set Gain. Might bump it upto 9psi and see how i go. Set is quite high at 55% and Gain is at 15%. This sound right for around 12psi? Anyone feel free to add what settings they have for around that amount of boost. Cheers

[nuclear_skyline]

What your settings are really depends on the turbo and the support gear, if you have a big, high flow exhaust you wont need as much set to get to the boost that you want, etc...

With my high-flow s2 turbo, to get to 11 pound I have about 28% set...

[Douse]

I would turn down your SET to something a little lower and and go for a few laps and then gradually turn it up until you reach the boost you require.

Turn your GAIN all the way down to 5% for the time being....

Mine SET is at 50% to 55% depending on the weather, but yours may be different to reach your desired boost....

Edited April 21, 2008 by Douse

[hardsteppa]

rather than start a new topic.....will do a stone-age bump. Having a small issue with mine, which is keeping the boost at 12psi in the mid-range revs. Seems to be that if I increase either set or gain, it will cause boost to go well over 12psi once you hit the higher revs, but boost is only 10-11 psi in the 3500-5000rpm range. This is for a hiflow stock turbo on r32 actuator.

[JonnoHR31]

Tried increasing the set gain (start boost)?

[hardsteppa]

yeah its on 9psi at moment, might bump it up a little more