TEDDER1

iTrader: (1)

i was messing with my intake last night and found that my air bypass valve is flowing out air ... lots of it, at idle.

i disconnected the vacuum hose and it stopped...

i then checked the charge relief valve. it doesnt flow at all, again at idle.

is it supposed to do this? then manual says to apply a vacuum pump to check it. i dont have one.

but doesnt the vacuum hold it closed to a certain preset point at which the surge produces enough positive pressure to open the valve? (ex. letting off gas)

or am i backwards on my theory...?

poss

iTrader: (5)

that is the way it is supposed to be.

vacuum opens the valve to let off excess air.
pressure closes the valve to keep it all in there.

TEDDER1

iTrader: (1)

ok so the abv really is only used at idle...

and the charge relief valve is the actual bov.

or do they both go at the same time? when you let off?

or is the 22hg in vacuum when you let off that opens the valve, hence the release?

poss

iTrader: (5)

at idle, they should both be open (i'm not 100% sure of the CRV's operation at idle, but i think it is open)

once boost is built, the ABV closes. Then at 3000rpm (on a stock system), the prespool door opens up and the secondary turbo begins to spin. The pressure created by the secondary turbo is vented through the CRV. Meanwhile the ABV is still closed to hold in the boost from the primary turbo. At 4500rpm, the CRV closes, the TCA opens to let full exhaust into the secondary turbo, and the CCV opens to let the boost from the secondary turbo enter the intake stream. it stays this way all the way to redline

hope you know what all of the abreviations mean