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Noob question but thought I'd double check..I got my greddy profec b spec 2 controller installed and tuned to 12 low and 14 psi high I removed it and am thinking of getting it installed in my Gtr, can it be put straight in with out needing it retuned

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  • 2 weeks later...

OP, what car did it come out of?

It all depends on actuator pressure as the boost controller is a % increase.. i.e. 50% on an RB25 actuator is not the same as 50% on an RB20 actuator

And as said above, I would reset the gain and setgain and tweak them from scratch to suit the setup in the new car.

Start from scratch. Its a pain in the arse to get right too. You need alot of road, alot of patience and alot of trial and error. Its a % over the current actuator setup and as said above, different tensions on different actuators will mean different things when you open your boost controller to 50%. Ive got mine on 0% low boost(14psi) and I think about 40 or 50% high boost for 20psi. Then you got gain, to make sure your boost is nice and consistent. You've also got your warning crap. Set this shit up wrong and you will be ON AND OFF BOOST, you can feel it and hear it loosing then building boost then hitting the limiter, losing boost and then building it up again.

You have set, which is your boost, then you have gain(set gain?) which controls boost falloff. Then you have start boost which is your desired boost -1psi, your warning which is your boost limit, +1psi of target boost(maybe even 2 - 3psi) then you have warning which is how much boost you would like to drop usually about 5 - 10% lower than your set. I had my boost controller, profec b spec 2, setup by CRD and they suggested the warning should be set to 0% all the time. It was perfect on my car. Anything more gave me the symptom I described above(on off)

Best to do it on a dyno where you can graph boost vs rpm so you can safely play with it without crashing your car into a tree or popping your motor because you weren't paying attention to both at once.

Also means you can get the boost curve nice and flat.

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