raced a talon

[bmyers]

raced a talon tonight-won but his car made hissing sound when he switched gears???? It almost sounded like the air ride on semis, what is it?

[dreaded_hope]

Being as it's a Talon, which can of course be had with a turbo, he had a blow off valve installed, that's what the sound was.

[bmyers]

purpose? what does it do? i dont know what the kids problem was but he kept trying to race me so i got sick of him revving his engine so i ran with him. although i think he was hoping for a different result

[Da Swami]

Blow Off Valves (BOVs) release excess pressure to keep the turbo from damaging the engine with over-boosting.

BUT!

They will also keep the turbo spinning when you let off the throttle (i.e. to shift) so as to not create "back pressure" and damage the turbo.



Factory blow off valves (and some aftermarket ones) will recirculate the pressure back into the intake and NOT make the "psssht" sound.




Non recirculating or only partially recirculating BOVs will make that sound, but are (I think?) illegal in some states.

[bmyers]

thanks guys

[MikeSomething]

It was the sound of his car crying in agonizing pain! Good kill.