2k1ws6

I got an sts turbo put on 2001 ta ws6. They forgot the bov and tuned without it and drove it around. How bad is this on the car and once they put the bov on will it help performance.

Boostaholic

iTrader: (4)

not at all, the BOV relieves pressure on the intake charge pipe when your throttle blade closes, it has no effect on performance at all but it can prolong turbo life as the turbo doesn't have to slow down as quick when you let off the throttle.

TchargedLS1TA

iTrader: (9)

Your BOV, like Boostaholic said relives excess pressure when you get off the gas.. Sometimes in high boost scenarios it can damage throttle bodies, turbos or blow piping apart, but I doubt it would in you case on a stock motor..

StoleIt

iTrader: (3)

A4 or M6?

longrange4u

iTrader: (2)

Yea because I dont think a BOV is required on an A4

StoleIt

iTrader: (3)

Exactly. You don't need a bov in an automatic transmission since your throttle body blade doesn't close when you shift.

2k1ws6

no its an m6

trtturbo

iTrader: (25)

Its not that big of a deal, but should be on there.
Basically, when you lift off the gas to shift the throttle blade shuts, backing boost up in the charge pipe. That will inturn back up in the turbo, slowing the wheel speed down. If you have your bov, when you lift, the boost blows off and the wheel speed stays higher meaning back in boost faster.
Its also not the best for the turbo.

If you ordered a kit with a bov and they didnt put it on, did they at least seal up the massive hole

toohighpsi

Without a bypass valve, each time the throttle closes and the compressor is up on boost it will drive the compressor into surge. Look at your compressor map, it is the line on the left side of the map. If the compressor pressure ratio is high and the mass flow is low you will go into surge. Surge is basically an uncontrolled reversal of flow through the compressor, at higher pressure ratios it can cause compressor wheel damage over time, like tips of the wheel inducer missing.

A bypass will also aid in response as stated elseware in this post. Hope that helps.