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D2 - Engine Bay Everything under the bonnet

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Old 13th May 2013, 07:41 PM
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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!
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Old 16th March 2014, 12:30 PM
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I took the fan off during the winter and I really felt the difference. car was a lot more responsive
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Old 30th July 2017, 02:38 PM
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Quote:
Originally Posted by nickid View Post
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.
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Old 1st August 2017, 12:14 AM
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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...
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Last edited by 27litres; 1st August 2017 at 10:12 AM.
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Old 16th August 2017, 01:22 PM
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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.
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