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beepbeep beepbeep is offline
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Join Date: Jun 2001
Location: Sweden
Posts: 5,565
3.6 fan is made to be quiet but it moves less air. There is a reason why Porsche used straight-blade 930 fan on turbocharged 3.6 and curved-blade fan on N/A engines.

20-30% overdrive won't cavitate the fan, tip speed is still way below mach 1. But it will eat belts and generators unless you move the generator out and gear it down.

It's not the speed that kills the belt but accelleration. Generator rotor weights a lot. If you increase speed by 30% you increase amount of energy in generator with 69%! If you use lightweight flywheel and "flip the throttle" you will cause major belt-slippage when trying to accelerate 2kg rotor from 1500 to 9000-ish RPM in fraction of a second.

Moving the generator might be a good idea even if you don't plan to overdrive the fan but do want to rev to 8000 RPM.
Thank you for your time,

Last edited by beepbeep; 08-09-2009 at 12:57 PM..
Old 08-09-2009, 12:55 PM
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