i know this is a rookie question, but here is goes. how does everyone have there MBC hooked up? i always thought it was between the turbo housing and wastegate. then i read about the bov being used. i ask because the mitsu. evo tech that installed my MBC plumbed with the stock boost regulator. the boost is set at 21psi then drops to 19psi. but in 5th gear it goes to 23psi then to 21psi. has anyone had this problem? and i thought the MBC would help to keep the boost from dropping down. any input would be helpful. thanks justin

im running the hallman rx MBC.

 

you may still get some boost creep but it should be less and now you can adjust it up to get the 20, i would readjust the boost if you get 23 then down to 21. most people get max boost in 3rd or 4th, i would do a couple of days worth of driving then make the change but if you cont to get 23 i would lower it. sometimes good gas and cold weather all for better boost .

 

I emphasized what the "problem" is. You'll need to bypass the stock BCS to rid yourself of the unstable boost. The easiest routing is taking all the stock vacuum tubing off and place one tube from the nipple on the turbo outlet to the inlet of the MBC. Then place another line from the MBC outlet to the wastegate actuator. Just cap off the BCS nipples and leave it plugged in (unless you like staring at the CEL).

 

i've capped off the stock boost solenoid.
i used the compressor nipple and the wastegate. its sweet
spike to 20 and than holds at 19. Perrin MBC

 

Hey Bom's_Evo: do you get exactly 20psi (then drop to 19psi) in every gear? Or do you get behavior more like BSREVOLUTION originally said?

On my WRX, I put the MBC between wastegate and turbo nipple and it seemed very stable. But everyone here kept insisting that you get more stable response if you put it between wastegate and the intake manifold feed (capping off the turbo nipple and stock controller, of course), so I did that. I'm consistently getting 1-2 psi more in 5th gear than in 3rd gear. My target is 20psi flash, 19psi steady, but if I set it for that in 5th gear, I'm only running ~17psi in 1st-4th. I'm considering tearing things back apart to use the original method.

Or, do you think you get this characteristic with both configurations?

Thanks,

Rob

 

im stock and i get 20psi then it settles to 19psi in all gears!
mine used to spike like crazy at the bov source. it would never go anywhere i wanted it too...even gone as high as 30psi...

but its set perfect now...im just waiting for funds for turboback and then mail in flash for some powaaaaa

 

Thanks for the info. I'm pulling that sucker back off and putting it on the turbo nipple.

 

i am unable to locate a good write-up for MBC installation... any help?

 

this might be useful https://www.evolutionm.net/features/...machvcorner/30

 

this guide is way too simplified, i want something step by step specifically written for the evo

 

ok, it is actually pretty easy, if you need any help I would be more than happy to talk to you over the phone or walk you through it

 

Dont know if anybody wants one still, but Im installing the Perrin MBC this weekend and will take lots of pics and do a writeup...if you guys want one.

 

that is a very sweet and tiny mbc, should be easy to hide

 

Bump

So did this ever happen?