blower bypass valve: twincharged ca18det supercharged turbo by-pass twincharger

[MadScienceVernon]

dude, I was going to do the exact same thing, you just took the guess work out of what dimensions the arms need to be, thanks a lot.

[thangcu36]

That's very clever. Can I ask which throttle body/size did you use to have both sides with outlets like that?

[twinchargedca18]

@thangcu36. i think it was off a RB30 motor - found in aussie skylines from 1986 to 1990 ish. i had a 2 1/2" alum tube welded to the other side so you end up with hose connections on both sides.

[michael174]

Hey There, do you find it leaks under boost pressure at all? I was running a procharger butterfly-type bypass valve on a blow-thru, remote mount roots blower and found it leaked pretty bad under boost, preventing good boost... This however looks like a great idea to dump large amounts of boost when the throttle is closed and you're rolling down a hill at 4000rpm and the blower is churning out huge volumes of air!!!

[twinchargedca18]

ive never noticed a problem with leakage. As i always use genuine throttle bodies, they are well designed so the seal between the butterfly and bore is always very good. The actuator holds it shut tight too. I use one for blower boost control (so it is partially open when target boost is reached), which is very stable, and i use one as you suggest for both over-run & blower by-pass at idle.

[buzzedo1]

appreciate you taking the time to post this, cheers!