fan power

[Asw]

Hi,
I was wondering if anyone knows how may horse power the engine cooling fan on a CU engine draws?
I have seen “air scoops” being fitted to the air intakes on vans and was wondering if they actually force any air engine bay (obviously only when driving “at speed”), and if by doing so the increased air pressure reduced the amount of power the fan draws.
I think my physics is sound but I don’t know how much difference it could actually make.

[Jackrobbo]

From your question I would assume that yes the greater the resistance against the fan the more hp is being robbed from the fan.

From my understanding though this is fairly nominal, due to the fan already rotating so you have momentum and I can’t imagine you’ll actually get much force through the scoops into the fan. The scoops aren’t designed in such a way to give heavy forces against the fan. I think the advantage of the scoops is more to do with thermodynamics and the temperature of air dropping at speed and entering the scoops rather than the force of which it enters the fan. Just my thoughts though.

[937carrera]

Modifications to the side intakes are a hugely contentious subject without conclusion, there's a very long WBX thread over on The Samba, and a shorter one on here.

[tobydog]

The power to cool the engine comes from the engine driven fan, or the induction of external air driven by the forward motion of the van by the ..... engine. Probably more efficient being done by the engine driven fan?