Thread: BOV orientation
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JFairman JFairman is offline
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Join Date: Jul 2006
Location: S. Florida
Posts: 7,273
On my car venting some metered air to atmosphere during upshifts and deceleration through the deceleration valve make the AFR go to 10:1 and it considerably reduces the exhaust popping on deceleration.

My fuel mixture curve is different than most though because I have the IA modified +20% fuel head which runs richer than a stock fuel head during deceleration and B.L. adjustable WUR set for high steady cruise and boost control pressures to keep the AFR's close to normal and not too rich for the current state of tune of my motor.

A friend of mine with a good running totally stock 930 CIS fuel injection tried venting the deceleration valve to atmosphere and his pops more than when it's venting into intake manifold or bypassing the throttle body like stock.

Maybe it's a steady burn after the turbine wheel instead of lots of sporadic explosions in the muffler inlet after the turbine wheel so you don't hear as much popping.
I can't see it so I don't know.
Old 12-08-2009, 04:33 PM
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