blow off valves - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

boss351c · 03-21-2005, 23:08

if you dont run a blow off valve to vent boost wen the throttle is shut do you really run the risk of hurting ure turbo? i mean really hate blow off valves and prefer the sound made with out it but i can understand the reasond behind using one as it could hurt the inducer blade...but so many ppl dont use dem. any ideas

ebxr8240 · 03-21-2005, 23:44

They are fitted to prevent compressed air hitting clossed throttle body and bouncing back onto compressor blades and spinning turbo backwards.Then when you open throttle it gets hit hard from turbine [exhaust] and spins up boost again..This VERY hard on turbo's especially on high boost[over 8 Lb].
Bov's can and are normally vented back past compressor but before maf.As this air has already been measured on maf motor...Some ricers disconnect it from inlet however and makes that noise..Aftermarket bov are made to do this also..But you can buy a vented back bov and you hardly hear them...Like std WRX's you hardly hear their bov/s...