Clutch Fan Delete/ Add Electric fan Controller

[Vetruck]

Factual HP numbers- I found the article, it was May 2000 Car Craft Magazine.

As you will see gains in HP with an electric fan over the thermal and non-thermal clutch fans, keep in mind that this test was done on a motor dyno, not a chassis dyno. What that means is the Viscous fluid which is silicone based fluid will seep into the outer area of the fan engaging it at cold temp on startup just for a few seconds and then the spinning motion of the assembly pumps the fuild back into the center of it disengaging it until it reaches somewhere between about 17-* and 200* operating temp (this temp varies based on manufacturer, but the temp is lower on OEM units than aftermarket and will rob power more often obviosluy when they come on at a lower temp.

These motor dynos are NOT real world situations and thus the Viscous fans tested do NOT get up to operating temp and restrict like they do when engaged. The nonthermal units are very light duty clutches and only spin between 30-60% shaft speed unlike the thermal units that spin 55-95 shaft speed. Hence the cold difference between the therm and non-therm units.

The difference from the electric to Thermal is 7 hp "cold" or "not engaged", and 9 hp "cold" with non-thermal. When these get hot the HP numbers drop significantly when doing max rpm dyno runs while hot and "engaged"

http://www.network54.com/Forum/21565...+Fan+Dyno+Test

Note: the HD thermal clutch fan is 18 hp draw when cold or disengaged. This is where yous ee the dyno charts of cars on chassis dynos like the WindsorV8 (Ford engine mr 3rd world, not farm equipment) pulling 25+ draw when the fans engage.