In reviewing my current intake and my turbo theory, I got to thinking…. Would not the best place to mount both the CRV (valve to bypass turbos under vacuum) and the BOV valve to waste extra boost, be on the Elbow where the ACV used to be.. I already have the hole, and I could move both.

This would allow an easy way into the intake under vacuum, a BOV near the TB for increased response, and scavenging of excess boost during shifts by tying the two systems together.

The only trick I can see would be how to get reasonably cool air to this spot for intake (could probably take it from under the car as long as it was dry) Or at the base of the windscreen, but this is a low pressure area at speed.

Any thoughts?

Dan

 

no...it's fine where it is

 

The CRV needs to be plumbed right where it is since it is part of the sequential turbo control system. It vents air pumped by the second turbo back into the intake during spool up. Without it (or if you move where it is connected) the second turbo won't spool up very well since its compressor output would be completely blocked.

The ABV (Air Bypass Valve, i.e. the stock BOV) is not supposed to open to bypass the turbo compressor. Many people have vented it to atmosphere to get that cool TFATF sound, and they would be sucking dirty air if it just bypassed the compressor. It may be true that they ARE getting dirty air, but some people have done some tests and the results have not been very clear. I think it is technically okay to vent to atmosphere, and that you won't get much dirty air in the engine. But then again, I think the whole operation is a bit frivilous.

The "bypass" action may be more that it bypasses the engine and lets the air compressed air back out to the atmosphere. It is really just a BOV for all intents and purposes. You cannot install it where the ACV is, because it would not work as a BOV in that position. A BOV needs to vent air between the turbo compressor and the throttle body. The ACV is not really connected to the runners, but assuming you cut holes there, it would be between the throttle and the engine -- not the right place for a BOV.

-Max

 

OK, I can clearly see that I was wrong on part of my question. I was thinking that if you allowed a ABV to be on the TB Elbow, you would increase air flow under vac, and let the turbos spool more quickly... but I can see how this could actually cause more lag while the turbos had to re-pressurize the whole system, as it would also vent off all of the boost very quickly.

 

max = makes everything so clear :-)

 

I think he means the other thing that sticks off the TB elbow not the ACV. Whats it called again?

 

isn't that part of the AWS?

 

Yep, I was talking about the AWS.. but really was wondering what would happen if you replaced the stock BOV with a ball type popoff valve that was set to vent boost over say 10psi.. would you not retain 10psi in your intake for the moment the throttles opened again.. Or would you just superheat the turbos.. hmmmm

 

regardless, you want the BOV to be on the hot side of the intercooler, you release more air that way and it saves the turbos....

people that put it on the elbow are stupid in my opinion