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uiuc240 · 07-08-2002, 09:39 AM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (sykikchimp @ July 08 2002,10:03)</td></tr><tr><td id="QUOTE">it's not just a noise maker. it is also to reduce lag b/w shifts, and I think it does extend the life of the turbo..

I mean your turbo is spinning somewhere around 100,000 rpm.. suddenly the butterfly shuts, and all that compressed air goes rushing BACK through the turbo, effectively spinning it the other direction, sort of creating a vacuum situation in the intake piping for a split second as you shift, everytime you shift. Then you get the lag from it spooling up again..

Personally I think they are nice to have, but not 100% necessary.</td></tr></table><span id='postcolor'>
You're right about that.  The only point I want to make is that the turbo doesn't stop or spin backwards when you close the throttle.  Remember, there are still exhaust pulses keeping it spinning in the right direction.  The only thing that is happening is suddenly there is no room for the air to go.  So what happens instead is the air bounces off the compressor and back out the air intake/filter (creating the chuff chuff chuff sound).  I'm sure this isn't GOOD for the turbo, but it's not life-ending either.  Maybe it would be if you're pushing 30 psi...but I'm not.

I agree that BOVs are a good idea, and on top of that they make a cool sound.  However, the original question was whether or not he could run without one.  And the answer to that is yes.  

Eric

07-08-2002, 09:39 AM	#14
uiuc240 Nissanaholic! Join Date: Apr 2002 Location: Naperville, IL Age: 46 Posts: 2,093 Trader Rating: (0)	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (sykikchimp @ July 08 2002,10:03)</td></tr><tr><td id="QUOTE">it's not just a noise maker. it is also to reduce lag b/w shifts, and I think it does extend the life of the turbo.. I mean your turbo is spinning somewhere around 100,000 rpm.. suddenly the butterfly shuts, and all that compressed air goes rushing BACK through the turbo, effectively spinning it the other direction, sort of creating a vacuum situation in the intake piping for a split second as you shift, everytime you shift. Then you get the lag from it spooling up again.. Personally I think they are nice to have, but not 100% necessary.</td></tr></table><span id='postcolor'> You're right about that.  The only point I want to make is that the turbo doesn't stop or spin backwards when you close the throttle.  Remember, there are still exhaust pulses keeping it spinning in the right direction.  The only thing that is happening is suddenly there is no room for the air to go.  So what happens instead is the air bounces off the compressor and back out the air intake/filter (creating the chuff chuff chuff sound).  I'm sure this isn't GOOD for the turbo, but it's not life-ending either.  Maybe it would be if you're pushing 30 psi...but I'm not. I agree that BOVs are a good idea, and on top of that they make a cool sound.  However, the original question was whether or not he could run without one.  And the answer to that is yes.   Eric __________________ 2002 Mazda Protege5 1989 S13 w/SR20DET (sold)