I've gotten the general impression that when guys have BOV issues on their supercharger setups, it's usually about a hi-bucks replacement for the Bosch unit supplied by Stillen. And frequently recommendations will run towards going back to the Bosch BOV.
Here's my question: what is the inadequacy about the Bosch unit that causes guys to look to a more expensive BOV to solve their problem? My basic understanding of the function of the BOV is to bleed off just enough excess pressure under light throttle, to close off when you're accelerating, but opening up wide when you suddenly lift off the gas under load. What makes one brand or design better than others at doing this job?

 

Ususally with such a large blower like the Vortech, your moving alot of air. And when guys start putting on pulleys like the 3.125", 2.87" and even the 2.62, that creats alot of air moving around. The thing I see with alot of the smaller type BOV, Bosch, Greddy style, they really dont let ENOUGH air out and cause compressor surge on the blower. I had the Greddy Type-S for a while and if it wasnt set properly it would make the compressor surge when I would lift throttle. I found a sweet spot with the BOV, but still found about 40% of the time I would get surge.

I switched to a LARGE Vortech Race Unit and even tightened all the way down, like I have it now, I get ZERO surge on the blower. I imagine the Mondo unit from Vortech is probably Amazing and is for 10Psi and flows sometime like 320CFM compaired to 280 that Race flows are 8psi!!

-matt