so i was looking at the tvsv manifold off a GT4 and had (what i think is) a good idea.

combine it with a MBC and make a dual stage boost controller.


see below diagram, what does everyone think?



the blue lines are vacuum.

VSV is the switching valve

BV is the bleed valve (boost controller)

the rest should be self explanatory

the idea is; that with the switch turned off, it runs whatever the w/g spring is (e.g 6psi)

and then when you turn the switch on, it bleeds some air back to the intake (adjustable), raising the boost level (eg. 12psi)

so, switch on, 12psi... switch off 6psi

EDIT: there should be a 1 way valve between the BV and the plenum, cbf editing drawing though

I'm not that experienced with turbocharging, but from everything I have learnt about it, your ideas seems to be the go.

Yeah, you can stack up multiple MBCs if you're keen. For me I just bought an AEM boost gauge with an electronically actuated MBC with hi/low boost off a momentary switch. This is called scramble boost, and is as awesome as it sounds.

Gav.

the solution above would be free for me, as i have a VSV and an MBC, a switch and a ****load of vacuum hose lolz