Ideally you would want to regulate fan speed by CHT. CHT goes up fan speed goes up and the opposite. Connecting it to the crank like it is approximates this behavior.
But, the blades are not dynamic and therefore are designed for a specific air velocity which will translate into an RPM band for optimal flow. Is this band narrow or big? *shrug*
So... does it matter if we're running outside the optimal band for the fan, but are still flowing enough air to keep the CHTs down? I do not think so. If we are not flowing enough air then yes... Will we know this if we are measuring individual CHTs? or should it be CTs? Or combustion chamber temps?
John's work is good and would be really really useful IF we knew what speed the fan was designed for... Then you could gear it for your average RPMs... higher for street and lower for track... or maybe its reversed.. hehehe
How about an electric fan slaved to CHT? I have no idea where it would go though... Maybe a side mounted alternator and an electric flat fan setup
Best regards,
Michael
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Michael
'82 Euro SC 'Track Rat' 22/29 Hollows, 22/22 Tarrets, Full ERPB F/R, Rennline Tri Brace, Glass bumpers, Pro 2000's, 5 pts, blah blah blah
'13 Cayenne GTS