handyandy

This may sound noob, but someone was telling me you can get a blow off valve for a supercharger.... is that true or no?

oxfordgt

Sure but what for. By the time you reach max psi it is time to shift.

handyandy

no idea, i dont know much about FI in general. how does it work

04mineralgreyGT

It's a bypass valve which is similar to a BOV. What it does is close under boost causing all of the air entering the intake to be fed into the s/c for compression. When you let off (get out of boost), say to switch gears, it makes a PPSSSSSHHHHHH noise. The bypass prevents blower surge. There are bypass valves that let the air escape into the atmosphere (more used in racing applications) and there are bypass valves that recirculate the air back into the blower itself (used more on street applications with lower boost pressures).

oxfordgt

With a turbo you will hit max boost (that you want) around 2500-3000 rpms depending on your set up which is why you need a BOV so you dont over boost. With a centrifugl supercharger you won't hit max boost till 6000 rpms so there is no need for a BOV. They work off of rpms so at 2500 rpms you might be around 4psi.With a screw type supercharger (like kenny bell) you hit max boost almost instantly but it will not go over.

lizzyfan

Most centri setups come with a BOV

1BadSonicBlue02GT

That would be what a wastegate is for. it only allows so much airflow so that you "dont overboost". a BOV is for relieving pressure when not on the throttle like between shifts and when letting off of the gas, so as not to cause surging which can damage the sc or turbo.

mustang_montana

you can setup the centrifugal blowers for a blowoff valve if you can move the mas so the bov is before it, otherwise itll just be venting metered air which is why they use bypass valves. the bypass valve keeps the already metered air and circulates it back through the blower.

Triisomy21

Go to the mph forums and do some searching. Most centri's come with a bypass, not blow off valve. You can switch to a blow off but you have to switch your MAF from draw through to blow through, which I have read is harder to tune.

lizzyfan

I understand that, just saying alot of folks get kits and the BOV is included. Bypass valve is standard.