difference between blowoff valve and wastegate?

[fogeesiksteythree]

it might sound stupid but wuts the difference between a blowoff valve and a wastegate? whats the difference in wut they do and wuts the difference in the parts?

[ales]

You won't believe it, but I was abou to post the same question!

My current understanding is that a wastegate lets some exhaust gasses pass into the exhaust bypassing the turbo and a blowoff valve lets extra pressure escape from the inake.

Looking for a more detailed explanation now.

[ivymike1031]

Sounds like you've got it right, ales.

[454Casull]

A blow-off valve releases the pressure that builds up when the throttle valve closes. A wastegate diverts exhaust before it hits the turbo when boost reaches levels too high.

[fogeesiksteythree]

hey ales, i think ive figured it out. i knew wut a wastegate was, but i wasnt sure about a blow off valve. wut a BOV does is that it lets air out when the throttle plate is closed. if there isnt a BOV, then the air would go back towards the comprssor wheel in the turbo and if the air were to hit the wheel, it would slow it down since its spinning in the opposite direction. hope that helps

[ales]

Yes, I knew that, I was just hoping someone would come up with pics and drawings and elaborate on the mechanism that both of these involve (well, BOV is pretty straight-forward, but a wastegate, i suppose, is more complicated?)