I guess anyone can answer this, but I know Random mentioned the Alpine kit already having this.

For emmissions purposes, I want to have the compressor bypassed when the throttle plate is closed. I'm wondering how to do this.

I've seen a Bosch compressor bypass for Saab's, but it has no specs. I've seen computer controlled wastegates that can be programmed to do this, but they are expensive.

Anyway, I'm just looking for ideas, and wanted to know how Alpine did it.

Thanks,
ac

 

You do nothing but install the kit.

The stock motor has a idle bypass on it, and you retain this feature with the turbo setup.

I am actually attemping to alter this a bit. At idle, my turbo cranks out more air than the engine can consume at 800 rpm. This actually creates about .5 psi of boost at idle. It forces the idle air bypass open.

I have been toying with the idea routing the IAB hosing to the intake. This would allow the idle air bypass to suck in filtered air, that was seen by the maf. It would have a "one way' valve on it that would prevent the "boost" pressure from bleeding out of the IAB into the intake under acceleration.

Originally, I was going to just strap a filter on the end of the IAB, but then the air entering the engine via the IAB would not be seen by the MAF. This would cause all kinds of problems.

I have not worked out all the details of this system yet...but I'm working on it.

 

That's kinda what I was thinking. Route the existing IAC/IAB line around to after the mafs but before the compressor. Possibly do a T with the recirculating BOV's return line.

Speaking of which, anyone recommend a recirculating BOV? I know Greddy and TurboXS make them, but I want to shop around before committing.

thanks,
ac

 

The TurboXS is the best/cheapest I have seen. I just don't see why the Greedy unit is so damn expensive.