Quick MBC controller question
 

Hey guys, quick question about manual boost controllers. I have a Grimmspeed manual boost controller, from what I understand, every click is ~1/4PSI, 4 clicks is a full pound and a full rotation is 16 clicks (therefor 4 pounds per rotation) I understand how to install, and I understand how it operates, what I do not understand is how the boost is calculated.

If I have it turned 24 clicks (6PSI) does that mean I will be boosting at 6PSI (which is my wastegate level) or does that mean I will be boosting at 12PSI (6+6)

It says you cannot boost below your stock waste gate spring, so I cannot boost below 6, that is fine, but does that mean one simple quarter click is 6.25? 4 clicks would be 7?

basically, is its "Wastegate PSI + Boost Controller PSI = boost"
or is it "Boost Controller PSI = Boost (Wastegate be damned, unless MBC is dialed it is below 6 psi)"

Thanks guys.

IT is, Wastegate PSI + Boost Controller PSI = boost

The MBC has no idea what is your WG spring pressure. What it does is increase on top of whatever it is 1/4 of a psi at a time.

And you should really have some sort of boost gauge hooked up.

I do, doesn't stop me from wanting to know how a MBC works :bonk: Many forums say many things, figured I would ask some pros.

Thanks Pimp :cheers:

Exactly. You have to think about how a MBC works. They work by hiding boost from the port on the wastegate making it think that it hasn't reached the PSI at which point it is supposed to open and start releasing exhaust gasses to prevent the turbo from creating any more boost. Also, I wouldn't take that each click is a 1/4 PSI too seriously. I had the Grimmspeed MBC as well, and it took quite a few times pulling over and popping the hood to get it adjusted to where I wanted it. Also remember that MBCs are greatly affected by the conditions of the air, so 11 PSI one day might be 12 PSI another day.

So I would have the grimmspeed MBC fully open, at that point, total boost would be 6psi (wastegate = 6psi) First click after that would be 6 1/4, then 6 1/2, and so on. That is what I am gathering from wastegate + mbc = boost

Yep. I found that you need more than 4 clicks to get a PSI though. Start off small and work your way up to your desiered PSI.