miketreid

What would the harm be in just venting the air coming out of the bypass valve instead of putting it back into the intake side?

Parastie

The AMF (i think that's right?) would tell the ECU you're getting this much air so you need this much fuel; IE you'd run hella rich when your car revs down.

Blade8r

it's AFM (Air Fuel Meter) not amf.

I'd like to know myself. is there anyway to bypass this air back into the compressor after the AFM?

i want to know what would work best.

and also what are the difference between a Vented BOV, and Atmospheric BOV. is there any other way to push excess boost out of the chamber and back into the compressor?

88IntegraLS

No issues if your afm is after the sc other than it being noisy, but if before, the vented air was metered air and the engine won't receive some air that the fuel injectors injected fuel for when the bypass opens. Result: rich fuel mixture, VERY rich.

And please put the throttle body before the supercharger inlet. PLEASE.

Novacaine

enlighten me why this is so important if he has bypass valve to prevent a spike in the boost from a sudden shutting of the throttle plates? I think I saw you write this before somewhere

Aaron Cake

iTrader: (1)

Already explained many times. If the throttle body is after the supercharger, at low throttle and light load the bypass valve will almost always be open, venting the extra air the compressor is attempting to shove into the engine. If you put the throttle body before the compressor, this problem is nonexistant.

edmcguirk

Or to put it another way, if the throttle is after the SC you MUST have a bypass valve because the SC will be ramming air at a closed throttle. The SC will be wasting 30HP or more at idle. The engine will not run. (technically throttle after the SC is the wrong setup but it will work)

If the throttle is before the SC, the bypass valve is only nice to have bacause the SC sucking at a closed throttle does not use very much HP. The engine will run just like a bigger engine sucking on a closed throttle - no big deal. The bypass valve is only necessary if you want better MPG than that theoretical bigger engine.

(roots only, centrifugal is completely different)

ed

SureShot

That is exactly how the stock 13BT is setup.
Check out the "fuel & emmissions - turbo" section in the FSM.
Advantages:
The AFM still sees net combustion air flow.
Less noise, although still audible.