Boost air -unwanted places

[327ire]

Iv been slowly working a turbo project for aaaages now and met 100's of crappy problems along the way.
link to the build..
http://www.e30owners.com/forums/showthread.php?t=6971

Boost air reaching unwanted places has been one of them. Iv never seen these issues in threads, maybe its a given that these issues are overcome. An m20 was never built to take boost so maybe some of you boost heads could help me with a list of things to plug/bypass.



1. Crank vent case.
I sealed the intake mani where the crank pipe meets the intake, vented the pipe to atmos instead of back into the intake mani.

2. Rocker Cover vent.
I vent the case to atmos and have plugged the TB end.

3. Brake Vacuum Supply?

My last hurdle is very lean issues. My vacuum pipe on the brake servo was broken at some stage so its not a "one way" job now. The brakes are crap and I loose all braking power when the engine shuts down (scary shit!). Im wondering is there a procedure/ adaptation needed in this system to avoid boost?

[staley_turbo]

Dont quite understand? Have you got a one way valve in you brake survo line?

[JJ26]

Get a one way valve back in the servo pipe, its there for a reason. This will protect the servo from any kind of boost and also most likely allow you to have one maybe two presses of assisted braking if the engine cuts out, enough to bring you to safe stop atleast. You may have risked damaging the servo if its been exposed to manifold boost pressures.

Also note if your servo is shot your engine will be pulling unmetered air in causing it to run lean.

[327ire]

Mmm that's what I was hoping to hear! Iv tried so many things with fuel systems, iv even changed the engine to overcome problems that have persisted. The fuel return was blocked which I wasted 100s of hours trying solve the mega rich issues and now, looks like the same thing has happened with my lean issues.

To reinforce this, the car runs like a rocket for a minute then runs mega lean after boosting a few times. Looks like you have solved a big one, thanks!

[staley_turbo]

Seems like you have quite a few probs there on quite a simple build. What management are you using?

[327ire]

I know! Its a case of bolt this on, plug this in, but not with me. Talk about one problem after the next. Total minefield.