*Michael.*

I have been reading a lot about turbo systems since I am planning my setup for the Miata..(the new Mini Cooper S is out of the picture, this will be more fun anyways).. One thing I am unclear about is the difference between a BOV and a wastegate. From what I understand a BOV vents the pressure that the turbo builds between shifts so that the turbo keeps spinning, that way it doesn't completely have to spool up again when you get on the throttle. The BOV is located on the intercooler tubing, the waste gate is actually connected to the turbo. So can someone give me some more info? How does each work and what they do..

led

What I've been told by a boostaholic friend of mine is...
The BOV releases pressure accumulated in the intake system between the turbine and throttle body, when you let off the pedal the throttle closes but the turbine still compresses some of the air. This compression can cause some back pressure on the turbine and can damage it. It happened a while ago to my friend for running the car quite hard without a BOV (dyno tested it). The way it works is by vacuum, when the throttle is closed vacuum is created in the intake manifold and this vacuum opens the BOV. The wastegate bypasses the exhaust gases that drive the turbine, when the boost reaches a limit the wastegate opens and no more boost is made. IIRC, there's a spring on the wastegate rated to some pressure, when this pressure is reached it opens.

Again, this is what I've been told so please correct me if I'm wrong.

streckfu's

Pick up this book by Corky Bell. It's probably the best book on turbo systems out there...

<a href="http://search.barnesandnoble.com/booksearch/results.asp?WRD=maximum+boost&userid=2T0802XA84" target="_blank">Maximum Boost</a>

<img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" /> <img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" /> <img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" /> <img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" /> <img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" /> <img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" />

*Michael.*

Thanks, Led

That explains it really well..

Also I just ordered the book, thanks for the suggestion!