Bov basics

[Martin F]

I've always been aware that for the best performance you should try to place a BOV as close to the throttle plate as possible.

But are there any problems with having it too close ?

I'm thinking along the lines of, you close the throttle quickly, vacuum signal in the manifold now needs to pass to BOV to open, the BOV mechanism needs to open. By the time this has all happened could the intake charge pulse have passed by the BOV if it is situated close to the throttle plate ?

[Martin F]

Guess nobody has too much knowledge on this one.

http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/wow.gif

[Cuthbert]

Nope, not me. Not completely sure how it works - is it the pressure differential?
How could the intake charge affect it?

[Stevie Boy]

Purely speculation but i would have thought as long as the BOV opens before the 'Intake charge pulse' flow reversal reaches the turbo's, the depression in the charge pressure should avoid the turbo/s stalling. So as long as the BOV is set-up right (opening as much as required etc) then all should be fine and dandy.
I've also been advised BOV's should be located near the throttle plate also, not sure what the theory behind it is, but manufacturers never seem to fit STD recirc's that close to throttle if anything they always seem to fit them near the turbo's.

I wonder whever it's more likely to be the best postion for Blow Off noise?http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/rock.gif

Anyway there's a Tech Focus: on Blow-off valves in this month's (well MAY '05) Japanese Performance mag, may be worth a gander.