Replace clutch fan with electric???
 

Anyone here done this? And if so what benefits did you see? I'm unsure how much power our fans rob, but they do rob something, so an electric fan setup might be a nice upgrade. Thoughts or input are welcome as I continue to research this.

I really wanted to do this a few years ago, after a bit of research it appears a lot of people think there will be no power gain, as you will simply shift the mechanical drag to electromagnetic drag as you increase the load on the alternator (which is effectively mechanical drag on the aux belt). Also you would have to ensure that the extra load on the alternator doesnt cause any problems by robbing current from the ignition system, fuel pump, etc, otherwise you would need to upgrage to a higher amp rated alternator, increasing auxiliarry belt drag even more.

But I dont want to put you off, it would be interesting to try and see the differences. You would have to somehow measure the inertia of the aux. belt before and after the mod.

I can't imagine the electromagnetic loss would be as great given that the fans would only run when needed as opposed to being constant like the current setup. I could be wrong though. I do doubt the additional load on the alternator would be an issue given people add many other electrical goodies to cars without issue. And our 8s have a quite robust electrical system.

I don't have any '8 experence in this area but I did do it on my Granada. I used a Scorpio electric fan set up and it's wiring which meant it only cut in as required, rather than 'running' continuously as the viscous fan that was replaced did. There was no noticible gain in performance/economy but what was noticible was how infrequently it would need to run. Only on the warmest days and only when sat stationary for more than an average traffic light cycle, would the fan need to kick in, the cooling system was efficeint enough without it's assistance to keep the engine steady at the required operating temperature.

So on this premise alone, and given the points made about mechanical drag v back EMF drag there would have to be some, however minute, increase in economy.

Having said all this, this does not mean that the '8 won't require more fan assistance.

Hope this helps, and for info my experience was with a '94 2.9L 24v Ford Granada Cosworth.

I have done this with my PF A8. I used the biggest Kenlow fan I could get onto the radiator. Even nodded the cowling. I used the supplied thermo prob set at 110c and wired an alternate switch to the existing electric fan for the AC. That fan would kick in long before 110c and start the Kenlow. I echo the previous comment that it rarely came on unless sitting in traffic for extended period. My reasons were diffent though as I was trying to generated space on the front of the engine for an SC pully!

I took the fan off during the winter and I really felt the difference. car was a lot more responsive

when is cold air is denser and engine is lot more responsive, i felt difference on my ex turbo alfa when hot and moderate/cold weather. Also engine have better cooling so must be better. I dont say there is no difference but also this must be considered too.

Mikki Jayne has done this, and even given the fan two speeds by utilising the aux fan resister circuit.

I'm thinking of following her example, maybe slightly modified...

I have experience building a custom thermofan setup in my old Holden 5.0 V8 Berlina. In the case of that car, I did get much more responsiveness and freer reving of the engine. Ultimately engine power was unlikely to be effected, but the lower load on the engine during initial acceleration made the car feel much faster (and it probably was, slightly). It also gave better fuel economy by about 0.5-1l/100km (2-3ish mpg) on the highway cycle. It sounded better too with that constant fan roar missing!

Yes I know clutch fans do a good job at reducing engine load during 'cool' cycle with their slippage ability, but they still create drag.
Also remember that the drag on the engine to drive the mechanical fan is 35-40% efficient.
The Alternator is far more efficient than that at producing electricity (90% or so) and an electric motor has similar efficiency at producing electro motive force.
That brings the overall electric fan drive efficiency to around 81%, which poos all over the engines mechanical efficiency.
So the resultant EMF drag on the alternator in driving the fan would be at least half that of driving the fan mechanically.

Why do you think all manufacturers now use electric fans (negating packaging requirements in transverse engine applications of course)?
I remember hearing similar arguments during the switch over to fuel injection from carburettors. What a load of crock that was proved to be!
Cars are also switching to electric power steering pumps, electric airconditioning compressors and even electric turbo and superchargers in the chase for higher efficiencies...

I may as well do this too. Looks like my overheating issue is due to the viscous clutch fan failing. In 30C queueing it heated up to 110C then the Aux fan kicked in and cooled it down. Yo-yo-ed like this a few times until the car was moving.