what is a blow off valve?

 

TTT

 

it's on a roots style supercharger- it opens up if the engine backfires through the intake so the supercharger dosent "blow off"

 

thanks

 

uhh, last time i checked, that wasn't exactly what a blow off valve is.

a blow off valve is used in either a turbo or supercharger configuration. What it does is allow any extra air forced towards the intake to escape when you let off the accelerator and the throttle plates close.

 

Good call.

It also makes a hissing sound when you let off the accelerator, which is an easy way to tell if a car is equipped with one without opening the hood.

 

Sorry, I only know about roots style superchargers and that's what they do, they look like freeze plugs and they accuatly "blow off" the supercharger

 

i think it releases off the turbo gases during shifts. That is the noise you hear from turbo cars when they shift.