Did you notice the ginormous twin scroll looking turbo on the BMW's??

http://www.gurneyflap.com/bmwturbof1engine.html

 

On racing engines this is done to reduce pumping losses. If you consider the volume of air that gets "knocked around" at high RPM's by the air being pushed down into the block by each piston on the downstroke, it all adds up to lost energy.

BTW, I'd sure like to hear that thing at full boost

 

those things boost at 70 - 100 psi??

 

Look at this Ferrari engine with the intake and exhaust sides of the engine switched. Weird stuff.

 

is that possible 100 psi, or is that a typo?