Thread: Blitz blow off valve = compressor surge?

I just installed my fmic and Blitz bov and the valve is slow to open and causes a bit of compressor surge before it releases excess air. I took it apart and cleaned it and it still surges. Any ideas why it's doing this?

Maybe to small of a BOV for setup? My buddy had a similar problem on his honda. His BOV was to small for the turbo he was running. He had to upgrade to a Tial BOV and problem solved!

Not too familiar with Blitz products, is it adjustable? If not whats the advertised Vacuum that it opens at?

Have you tried pressing in the valve with your fingers and see how far and how easily it open?

Have you checked your vacuum source? Is the like in good non leaking condition?

Finally check the nipple on the BOV where the vacuum source goes, try to put vacuum on it with your mouth or a vacuum pump and see if the valve opens and how easily.

It's on a bb t25 and the blitz came off my buddy's R33 Skyline. And it only surges when the throttle first closes.

You mean the boost pressure would still be in the Vacuum line, even after the throttle body closed? Thus not drawing vacuum fast enough to open the valve and saving from a surge?

I'm sure the spring is too strong inside the BOV then.

I thought that may have been the problem also, but it doesn't get too stiff till it's compressed more. It only surges initially and remains open as it should. The line going to the vacuum nipple on the bov is longer than with my factory setup, but I'm not sure that the length of the line is the culpret.

Try messing with the adjustment screw on top of the BOV. I know that all Blitz BOV's are adjustable maybe it's adjusted too tight. Also make sure u have a good vaccum source for it.

what kinda boost pressures are you running

i have this BOV, if it is the trumpet style you need to adjust the top screw .
It is probly too tight .