What is the purpose of a blow of value?

I thought its purpose was to releave excess boost, but isn't that also what the wastegate is for? Why would you need both?

 

Yes, it does relieve excess boost, but not the same way as a wastegate.

The blowoff valve (BOV) helps extend the life of the turbo by venting the pressure buildup when you let off the throttle. Otherwise, the boost pressure would back up into the inlet and stall the turbo's turbine side, which puts a lot of stress on it and causes it to wear out sooner.

 

^^^exactly. it's called turbo surge.

 

Thanks for the replies.

So if I understand correctly it just alleviates back-pressure to prevent "binding" of the turbo.

 

yup

 

THIS IS THE FUNNIEST THING I'VE EVER HEARD...

 

why is that the funniest thing you've heard?

 

Because it's a typo and he amuses easily. "of" instead of "off", "value" instead of "valve".
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BODY SCIENCE

 

So how does the wastegate relieve boost?

 

It doesn't relieve boost like a BOV it restricts the turbo. A wastegate sits in the exhaust system before the turbo. When pressure builds high enough then it starts venting exhaust around, bypassing the turbo altogether. This keeps the turbo from constantly increasingly the boost until Bad Things Happen.

 

LOL you dont even notice it.... Guess you'd write it the same way... :D

 

I see.

 

One more "silly" question. Is the BOV strictly a part for the turbo or can it be put on the stock engine alone to give the engine that "wooshing" sounds at high revs?

 

..now THAT is a silly question! :D

S

 

Lschiavo,

I appologize for my spelling errors. I was far too hasty when I was typing my question. The spelling errors in my post were so bad that nobody understood my question, but instead fell out of their computer chairs laughing at my idiocy. Your superiority is obvious and overwhelming.

Thank you for the value you added to my education.

j00 ru><0r.

 

You can add a BOV to any intake system, but with no positive pressure, there is no pressure to relieve and hence, no "whoosh". There are electronic piezo speaker systems that will make this noise, but it's kind of, well, ...

The BOV only relieves pressure when you lift off the gas and the throttle plate closes (or partially closes). The compressed air that was formerly filling your combustion chamber now will escape through the BOV instead of hitting the forward spinning turbine fins. This does two things, one-it saves wear and tear on the turbo shaft (as mentioned above) and two-allows the turbine to maintain some of it's rpm's. This helps when you get back on the gas to get to max boost faster.

The wastegate is simply used to control boost, not bleed any off. the wastegate is boost pressure activated and opens a valve to release exhaust gasses before they hit the impeller blades in the turbo.

 

....if you put one on the intake of a 'normal' car, would that make it a SUCK off valve?

Just askin. :D

S

 

Well, it would certainly SUCK.

Peace
policy

 

adds 87 whp also

 

Hey, I thought your typos made you look bad too; I just didn't say anything. Sarcasm doesn't help either. It just emphasizes the fact you don't care how sloppy you are.
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M103 ENGINE

 

Darn, if I would have known that, I would have never went turbo, just got a BOV, that could come in handy on a bad saturday night! That quote IS THE FUNNIEST THING i have ever seen!

 

BOV Sound without a Turbo? Of course it's possible!!! Just not with a BOV attached to your intake though... It's called http://www.sunamiturbo.com/

LOL!!!

 

I can't believe that product even extists. Even more scary is that someone has probably purchased one.

 

^ Yeah, no kidding. Up next is a RWD burnout smoke creator gadget for the poor FWD rice rockets. All you have to do is rev it in neutral and the smokes will come out the rear wheels :D