Landracing Forum

Tech Information => Technical Discussion => Topic started by: manta22 on November 23, 2014, 10:49:27 AM

Title: Electric Fans
Post by: manta22 on November 23, 2014, 10:49:27 AM
Does anyone use an electric radiator fan on his LSR car? I realize that at speed there is plenty of air going through the radiator to dissipate the heat but what about cooling off during the return or running the engine in the pits or during a warm- up in the staging lane?

I'm trying to decide if it is worthwhile to mount multiple 12V fans on my radiator.

Regards, Neil  Tucson, AZ
Title: Re: Electric Fans
Post by: Seldom Seen Slim on November 23, 2014, 10:59:52 AM
Well, Neil -- not precisely the answer to your question, but bikes have electric fans and they work like you expect -- not during a run, but for sure after the run has ended.  I usually shut off the engine when coasting down for the return road -- and then turn the ignition back on to let the fans cool stuff while waiting for someone to fetch me.  I expect that's how car fans would be used, too.  Anybody with car experience?
Title: Re: Electric Fans
Post by: Stainless1 on November 23, 2014, 11:08:16 AM
Neil, are you going to circulate the water without the engine running?  if so then the fans may help cooldown if you get the chance to hot lap.

Warming up should not require a fan, are you planning a thermostat?  It will help warm up.... we warm a little, let the motor heat soak, then warm again when it is our turn to run while waiting for the track to be ours... We do not run a radiator any more, found it didn't do much in our situation.
Title: Re: Electric Fans
Post by: kiwi belly tank on November 23, 2014, 12:35:43 PM
Use a thermostat & a fan with a radiator. Thermostat to speed warm up & fan to prevent overheat.
  Sid.
Title: Re: Electric Fans
Post by: 631 on November 23, 2014, 01:41:49 PM
I started out with a big 12v fan on the Mclaren and then took it off as it was not needed at the salt or the open road races.  It is nice to have the option to put it on for tooling around town or a slow start line at the Silver State where you move up under your own power.  Once you are 30 mph or better it is just propeller drag with proper airflow.  Mount it up so you are all ready to go for a ride on Saturday nite!  Rex
Title: Re: Electric Fans
Post by: Dynoroom on November 23, 2014, 02:36:59 PM
I had a customer in the GT class who had/used a large electric fan. It failed (came apart) at speed (230) on one run putting a hole in his radiator.
Maybe it was old, damaged, or???

Just something to think about IF the fan is in the air stream.
Title: Re: Electric Fans
Post by: Glen on November 23, 2014, 02:53:46 PM
We have a 4 fan cluster  fan radiator mounted as there is no air passing through the radiator After the run the driver leaves the fans run for a few minutes. This is on the 444 Vesco liner.


Title: Re: Electric Fans
Post by: redhotracing on November 23, 2014, 03:09:53 PM
We run dual electric fans on our /BFALT as there is little air
flow running through the radiator. As others have written, it
helps cool everything off after the run, if nothing else. This
is on a wet sumped car, so we don't have the luxury of oil
warm up prior to a run without getting hot water, as well.
Title: Re: Electric Fans
Post by: manta22 on November 23, 2014, 04:29:02 PM
Thanks for the valuable suggestions, everyone. I think what I'll do is provide mounting points for an aluminum  panel with 4 to 6 Nidec TA-600 fans mounted on it so I can quickly fasten the assembly on to the radiator if I find that it is needed. I'll also need to add a connector for the 12V fan circuit.

My original plan was to use a single large fan ( Flex-a-Lite 150), if necessary, but the ducting on it is too large. I'll probably sell it.

Regards, Neil  Tucson, AZ
Title: Re: Electric Fans
Post by: Buickguy3 on November 24, 2014, 11:55:01 AM
   Here's another twist. We were told in tech that in Gas Coupe we would have to remove the fans as they were considered:"blocking" the radiator air flow and creating an advantage by forcing the air around the front of the car.
    Doug  :cheers: :cheers: :cheers:
Title: Re: Electric Fans
Post by: manta22 on November 24, 2014, 12:23:07 PM
   Here's another twist. We were told in tech that in Gas Coupe we would have to remove the fans as they were considered:"blocking" the radiator air flow and creating an advantage by forcing the air around the front of the car.
    Doug  :cheers: :cheers: :cheers:

Doug;

That's a strange rule....  :?

Regards, Neil  Tucson, AZ
Title: Re: Electric Fans
Post by: jacksoni on November 24, 2014, 01:13:42 PM
   Here's another twist. We were told in tech that in Gas Coupe we would have to remove the fans as they were considered:"blocking" the radiator air flow and creating an advantage by forcing the air around the front of the car.
    Doug  :cheers: :cheers: :cheers:
this would suggest that a stock fan and shroud as delivered from factory would be illegal. This would apply in Production as well. Somehow I don't think this is the intent of the rule and if told that would bump to chief inspector etc.
Title: Re: Electric Fans
Post by: Buickguy3 on November 24, 2014, 10:29:02 PM
       I think that the inspector that looked at the car [our Jag] viewed it that when the fans were not running they effectively were restricting air flow through the radiator like a smaller core would do and would give an advantage. We removed them and never missed them. Not sure they were really necessary above about 35 mph any way.
      Doug  :cheers: :cheers: :cheers:
Title: Re: Electric Fans
Post by: jacksoni on November 24, 2014, 11:41:46 PM
       I think that the inspector that looked at the car [our Jag] viewed it that when the fans were not running they effectively were restricting air flow through the radiator like a smaller core would do and would give an advantage. We removed them and never missed them. Not sure they were really necessary above about 35 mph any way.
      Doug  :cheers: :cheers: :cheers:

OK, but many cars now (maybe all of them) have electric fans and they surely don't run all the time. I count this as an interpretation not supported by the rules, but that's just me.
Title: Re: Electric Fans
Post by: Rex Schimmer on November 26, 2014, 12:11:17 PM
My bet is that an electric fan probably is not a restriction when not running. I would bet that the fan "windmills" when it is off and the car is at speed, which gets me to Mike LeFevers' comment about an electric fan exploding at 240 mph. Maybe you should be concerned that at high speed and with the fan off it may be windmilling at a speed far above its' rated rpm which could certainly cause it to explode. Maybe you should have the fan in the on position if you are running fast as the fan motor during windmilling will probably act as a generator and being connected to the car battery could possible keep it from exceeding its' design speed. Plus you would be charging your battery! A hybrid Bonneville car!!! What next ?

Rex
Title: Re: Electric Fans
Post by: SteveM on November 26, 2014, 04:39:33 PM
Speaking of an electric fan working as a generator, it took me and my partners a while to figure out why the Rampage would not shut off immediately upon throwing the master disconnect switch.

We did a lot of head scratching before finally figuring out that if the electric fan was running, it was back-feeding the electrical switch panel, which in turn kept the engine running until the fan slowed down sufficiently.

A little re-wiring, and a relay solved that issue.  I offer that just as a little bit of knowledge to put in the memory banks in case it's ever needed.

Steve.