Stavros
Active Member
no idea about the ALS stuff but thats not strictly true about BOV. Some are open naturally and closed by pressure then open again when you let off ( eg bailey one's which is why they are shit ). Others are closed normally and it's the sudden vacuum which opens them a la HKS which is better
so in theory a shit BOV could be slightly open which is counter productive to what you are saying ALS does in the same way you were saying you can get slight turbo chatter when using als for a similar reason ( not enough pressure escapes through the als valve so has to go somewhere. )
that may all be utter bollocks if i'm not understanding it correctly
I think you're a lil bit mixed up mate.
NO BOV is naturally open (impossible due to their design), just some (most back in the day before cars ran AFMs so needed them to be shut) have springs weak enough that they stay open thanks to the vacumn sucking them open even at idle.
All Jap ones and most modern twin piston ones are made with strong ass springs so they only open during the time where there's the biggest pressure differential on both sides, ie for the second or two after the throttle is lifted from full boost, where there's BIG vacumn showing in the vac side of the BOV, and boost pushing on the other side still.
But either way, no BOV is best, as any at all removed some of the air that should be used to make the ALS work.