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mechanical fan vs electric?? with proof?

Marvelous3 said:
Seems that instead of swapping efans everyone should be running 93 instead. Those gains from good gas alone are silly.
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that's more due to the year old ****ty gas that was already in the tank than it was going from freshish 87 to fresh 93. I suspect the sweet point would be mid-grade, or 87 with a gallon of e85 if you can get it.
 
thismachine13 said:
That is what you got from his "scientific" test? A worn out mechanical fan on a sketchy running 244 from 3 runs that may or may not have had decent gas coursing through the fuel line.

Sounds legit.:roll:
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I'm not saying I've had a lot of volvos on the dyno over the past... decade... but if the mechanical fan were a big deal, this car in particular would have shown the most gains with and without.



but, get your perfect car, drive your ass down from BFE ark, and we can do a rinse repeat for $100/hr whenever you're ready.
 
My jeep has a hydraulic fan. Runs off the power steering pump. It's quiet, I don't even hear or feel it working. No matter how hot it gets, whether if I'm towing or offroading..the engine temp is solid.
 
gsellstr said:
For test purposes only, bend an L bracket, under a water pump bolt, engaged into the fins on the fan clutch.
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..no. they don't generally stay coupled that long, once the car gets above a reasonable mph, the airflow across the front from driving through the air outweighs what the fan produces, and cools things down enough where the fan decouples and freewheels again. A frozen fan clutch is a worst case scenario that requires a repair, not a normal use-case scenario. Might as well lock one ebrake shoe up and hit the rollers "just to see", or pull a plug wire.


speedn_j said:
My jeep has a hydraulic fan. Runs off the power steering pump. It's quiet, I don't even hear or feel it working. No matter how hot it gets, whether if I'm towing or offroading..the engine temp is solid.
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that does sound like something decidedly chrysler/mercedes, that's funny (sorry). probably not all that bad though really aside from the plumbing aspect.


So, from the peanut gallery of pot-shot-takers, I expect to see some dissenting dyno graphs this weekend. Pony up and put up, or shut up. I might have a dyno in my back yard that I do with as I please, that does not mean it was free or that my time is free.
 
James10952001 said:
On that note, do all LH 2.4 ECUs support controlling the electric fan? What if I burn a ROM from a 940 with factory e-fan and put it in the ECU of my 740? Using the ECU to control the fan seems like the cleanest way of doing it.
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Not all ECUs support an e-fan, so grab one from a doner that has one installed from the factory. Forget swapping chips and just swap the whole ECU. As long as the engine is the same and the 940 didn't have an immobilizer installed it should work out just fine. AFAIK, If there was an immobilizer installed, then you'll have to get a chip burned to replace the onboard one. That's what I did for my project 740 (see signature) with a 984 ECU, works great with the computer controlled fan.

You'll need to populate pins 10 and 11 on the harness to run a wire to the low and high speed relays on the fan, but it's simple, easy and avoids hacking radiator hoses to install thermal switches.

A list of ECUs with information on motors and if it has an immobilizer can be found here: http://forums.turbobricks.com/showthread.php?t=84817
 
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Just got a call from a buddy who works inside GM and the 2020 Corvette will be using a mechanical fan. Apparently the leak of this news is creating a wave of change within the auto industry. All car manufacturers intend to switch to mechanical fans by 2021. The difference they say between mechanical fans and efans is infinitesimal. As well hand cranks to start the engine will be offered as an option.
 
thismachine13 said:
Just got a call from a buddy who works inside GM and the 2020 Corvette will be using a mechanical fan. Apparently the leak of this news is creating a wave of change within the auto industry. All car manufacturers intend to switch to mechanical fans by 2021. The difference they say between mechanical fans and efans is infinitesimal. As well hand cranks to start the engine will be offered as an option.
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your mom called to make an appointment, and mentioned that you need to move out of the basement.
 
Thank you Kenny for spending your time to show actual data. Despite some morons who want to nit pick and put down your info I found it very valuable to start to quantify this.
 
JerryJS8 said:
Not all ECUs support an e-fan, so grab one from a doner that has one installed from the factory. Forget swapping chips and just swap the whole ECU. As long as the engine is the same and the 940 didn't have an immobilizer installed it should work out just fine. AFAIK, If there was an immobilizer installed, then you'll have to get a chip burned to replace the onboard one. That's what I did for my project 740 (see signature) with a 984 ECU, works great with the computer controlled fan.

You'll need to populate pins 10 and 11 on the harness to run a wire to the low and high speed relays on the fan, but it's simple, easy and avoids hacking radiator hoses to install thermal switches.

A list of ECUs with information on motors and if it has an immobilizer can be found here: http://forums.turbobricks.com/showthread.php?t=84817
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Replacing the whole ECU is not something I particularly want to do since I've already got a spare that's the same as the one in the car. I can burn EPROMs and populating the connector is no problem but if the actual ECU hardware is different I'll probably just keep the mechanical fan.
 
Definitely thank you for taking the time to do the dyno pulls! It'll be really cool to see the gains as you get the car back to running well in stock form, and beyond.

The 240 rally car sees a lot of high revs and sideways action, so air is not always going into the radiator, and the tropical clutch is almost always engaged by the end of a stage (who knows when it kicks on). So for us, the power loss from a fully locked up fan at 4k-7.5k rpm is actually of interest. The good news about that setup is that we have never seen temps over 200F on stage.

I just installed a shrouded e-fan from a 9 series and used the thermo switch in the radiator as well as a switch inside. Heading to one of the hottest rallies we do every year this weekend, will report back on how the system worked.
 
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