m

 

I just installed one last week. Only problem I think the stock bypass valve leaks under higher rpm if you are trying to maintain 19psi. You run a hose off the bottom of the MBC to the turbo Actuator and the other hose from the MBC to a "T" in the line between the bypass valve and itake manifold. Exactly like this install:http://www.jonesland.com/evo/MBC_Install.htm.

Be sure to have a boost gauge.

 

m

 

yes, I believe it is a 3/16" T. THe hardest part about the install was getting to the Turbo actuator. I had to remove the intake pipe(from the turbo to the MAF to be able to get my hands on the hose to the actuator. Let me know how it turns out.

 

m

 

Did you pull all the stock hoses from the factory boost control solenoid? If so you need to cap the nipples on the turbo housing and intake pipe. I pulled all the factory hoses off and capped everything. I seem to be loosing boost after 5500rpm--I think it's the factory bypass valve. But I'm not getting any sounds like you describe. I just bought a greddy type s--I'll put it in tommorrow.

 

I just installed a JoeP MBC on my buddies EVO 8... We are getting this exact same shrieking sound at 1.4 bar and 5800 rpm (approximately)...

Cannont figure this out for the life of us... Can it really be the BOV leaking air past - it just doesn't seem like it would do that only at that RPM, where at lower RPM and the same boost it's ok...

This one has got me weirded out... We even tried two different routings of the MBC. First we tried it like on my '91 DSM, and tee-d into the BOV vacuum line, then tried it directly off the J-pipe....

Any ideas, solutions, etc???

Edit: while adjusting the BC, we had boost as far as 1.7 bar (25 psi), and didn't stay in it, but it also didn't make that shrieking sound either, in a 2nd gear pull... Unless the BOV's vacuum supply line has some sort of bleed fitting for over 6k (where it bleeds off stock boost anyways)

-Cody
'91 Talon TSI AWD
'93 3000GT

 

m

 

Yup, removing stock ram air fixed the problem... time for an aftermarket cold air solution...

 

m

 

im getting that same problem, but you really think its the ram air?? Oh by the way, i normally dont have the shriek, it really only happens when im "racing" my motor like flooring it from first and shifting hard to second and such. Ill try the ram air thing. If it works, ill just move the hoses out of the way and put it back.

 

Let me know if it works?? Is yor MBC like the one that Buschur sales?? Thats is what I am going to attemt to install tomorrow!!

 

Yup, for some reason removing the ram air works. I even got the hoses to go around it but it still causes the problem.