3STGE question (ISCV question)

[sergei]

Hi, I am in process of assembling back my ST165, I am changing all vacuum/air hoses, I've removed the TVIS VSV, FPR VSV, and metal piping behind the intake manifold (to keep as simple as possible), one thing I've noticed that ISCV (Idle speed control valve) originally vents back in intake before turbo (after AFM) bypassing the thottle, in NA car it would seem normal, but in turbo car, under the boost it seems that it would vent boost back before turbo thru that valve;
The question is: does it actually need 1 way valve there to stop boost "leak", or the valve under hot operation provides sufficient seal to stop bypassing boost? As it looks that from factory it did not had any sort of valve there.

[Malcolm]

you don't need a valve in the ISC line, I'm not 100% sure but I imagine the ISC itself probably closes as soon as you put your foot on the accelerator, and if not it may act as a one way valve

[sergei]

maybe it is electronically controlled, but I've tryed blowing thru it both ways and it is not one way... well thanks for reply, you are very helpfull.

[Akane]

What the hell are you guys talking about ?!??!?!

The pipe you guys are talking about takes air from after AFM, before turbo, and is controlled electronically to let the car idle.

it's not venting anything.

[sergei]

think about it, if valve stays open, boost from intake manifold will vent back in the intake pipe before turbo

[Akane]

ok.