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911st 911st is offline
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Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
AAV removal, why? Bigger CBV.

I hear some are taking the AAV's off there turbos. Why is that?

I thought the AAV was there to bypass air around the Throttle Plate between shifts.

It works along with the Compressor Bypass Valve to help keep the compressor wheel spinning so boost stays up and it also makes things easyer on the turbo.

I even added a larger flow adjustable CBV that I set up in a reverse orientation and was able to get no boost drop between shifts on the factory boost gauge.

Compressor pressure would hold it open from one side and vac wold pull it open from the other side at cruse and I would set is so when boost built in the manifold it would use the mechanical advantage of a biger piston in the valve to push it closed when accelerating. I use the adjustable spring tension to fine tune it.

It also made it so I had faster boost onset with accel from cruse. I would get instant .2-.3 bar boost from cruse at freeway speeds if I recall.

My reference is the 91 -94 C2 Turbos and it has been a couple of years.
Old 06-08-2008, 11:26 PM
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