With all the talk about electric fans, I'm kind of curious if anyone has dyno #'s to show how much power is gained. I remember years ago CarCraft or HotRod did a engine dyno test with about 6 different flex-fans and clutch fans, but I don't remember the #'s.

 

you should see quite a bit....17 or so hp.

 

Actually you will see very little. I'd say on a chassis dyno around 5HP or less. Remember your mechanical fan draws little power when the clutch is disengaged (free wheeling). And on electric fans the extra amp draw increases electrical resistance on the alternator taking away .5-1HP. I think the main benifit of electric fans is how little space it uses.
Philip S.

 

Actually I saw 17 HP on mine.......Before and after dynos. Only change was the Fans.

 

That's probably because the dyno with mechanical fans the clutch was engaged.
Philip S.

 

And? Still a 17 hp gain......

In the summer the fan is like a parachute on the motor....Bottom line the fans free up HP.

 

17hp is 17hp ... I don't know many more ways to look at that.

Both of you guys are right though. I think unlocked, it's not much problem, but sitting in a staging lane it will sure get hot and lock up. I think it might be a little more than your thinking though.

 

Well I guess so. I just don't think it's worth it to me because my fan is always disengaged unless on inital start up when the fan is supposed to be enganged, the disengages a short time after. How many amps is your fan eating up? I know 28 amps of draw is something of .516HP loss.
Just curious.
Philip S.

 

I will take the .516 hit.....the fans help with more than HP.

 

That's cool.
Philip S.