Thats actually what I was trying to figure out.. Whether it ran in tandem with the solenoid, or replaced it..

 

The MBC replaces the existing lines, including the ECU controlled solenoid for bleeding off boost at higher RPM.

 

I hooked up my TT/boost gauge tonight...then I went to hook up the MBC and became very confused. I have read some conflicting info, and I'm not sure where to hook in the MBC. I am in no hurry to get it hooked-up, I want to do it right. Does anyone have an Evo-specific diagram or picture that shows what exactly to do?????

Thanks.

 

Don't feel bad.. I had the same reaction.. the last time I did this was when I put a crude first generation MBC on an '89 Isuzu Impulse Turbo and I remember just having to splice into a line, but not bypass anything..

 

I experienced the exact same thing when I upgraded the exhaust on my car... the boost went up 2 psi, so I had to readjust the controller to lower down the boost back to where my fuel system could handle it.

 

From what I know, it's that boost solenoid thing that controls the boost. I think the wastegate on the Evo is only set to about 10psi. The solenoid does the rest (letting it spike to 19psi, and dropping to 16 or so). Installing a boost controller bypasses this solenoid, so boost stays as high as you set it (I have mine at 20psi, but it does drop off it 18.5 - 19psi around redline). This is probably due to restriction from the stock exhaust though.