ejj

iTrader: (5)

Do your BOV's open when engine braking? IE: If you're coasting at 80mph (3400ish RPM) and you let of the throttle, does is open?

Mine always has, but I've had several people mention that it "looks" like my BOV is way too loose because of how much of the adjuster screw is showing (Pic). I tightened it a little at the track, and now it doesn't open except under "hard" shifts.

Just wondering what's considered normal.

Stephen Max

iTrader: (59)

It should be open anytime you're not boosting. At 3400 rpm the blower is pumping way more air than what your engine needs. At WOT at 3400 rpm your engine is taking in about 150 cfm, so at partial throttle it's taking in considerably less. At 3400 rpm and assuming a 3.33" pulley, your blower rpm is almost 22,000 rpm. If you look at a compressor map for the V1, at 22,000 rpm and 100 cfm you're operating pretty at the surge line, so if your bov is not open, then your going to be generating a lot of heat in the intake.

I've got a Blitz DD bov, and I've found that at idle I get considerable blow back through the intake of the blower even at the loosest setting of the screw, and I get surging during shifts because the bov doesn't open enough to release all the air. I fixed that problem by replacing the spring in the bov with a weaker one that I found at Pepboys, so now my bov opens a lot wider than it used to. I may be losing about a psi of boost at redline, though, due to leakage. I think the boost pressure near redline may be enough to force open the weaker spring.

[maxi-overdose]

iTrader: (3)

you have 3 times more threads than mine. Either yours is too loose or I need to send mine in for inspection.

greddy type S leaks once the throttle is closed....regardless your RPM. I think this is for recirculating purpose.