Has this riddle been solved then lads??

I might have a stab(probably in the dark......)

Is it to do with the speed/amount of air hitting the exducer of the compressor wheel? Either blocking the amount that hits the outer tip as this will turn the wheel harder/quicker kinda like the larger the gear on your pushbike? Or is it somehow increasing the speed of the air that will hit the outer tips by increasing the pressure using the shroud to "tune" the air?

Thats probably bollox but I wanna, like Steve, know the anwer from both Karl and Stu and they wont post the answer till we try to guess!!!


P.


I have heard a few really cool sounding Jap motors and have never known what made them sound so mint....maybe this is the reason?? Has anyone seen the viddy of the 200SX S13 with 513BHP doing donuts this sounded really highpitch when spooled up??