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Old 11-12-2017, 12:10 PM   #1
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Default Reducing motor Temps

A Question

when my motor temp is high i am told to go down on my gearing

so if i am running for example a 78 spur and 32 pinion and a FDR of 4.5 do i go up a pinion or down a pinion or is the FDR up or down in the number

?????
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Old 11-12-2017, 12:30 PM   #2
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Going down a tooth on the pinion (or up a tooth on the spur) will help to keep the motor cooler in most circumstances. This raises the FDR. Higher FDR = cooler.
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Old 11-12-2017, 12:40 PM   #3
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Going down a tooth on the pinion (or up a tooth on the spur) will help to keep the motor cooler in most circumstances. This raises the FDR. Higher FDR = cooler.

thats great thanks
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Old 11-12-2017, 10:24 PM   #4
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Originally Posted by andrewd View Post
A Question

when my motor temp is high i am told to go down on my gearing

so if i am running for example a 78 spur and 32 pinion and a FDR of 4.5 do i go up a pinion or down a pinion or is the FDR up or down in the number

?????
Well it really depends on where in the motor's powerband you are running. If you are already undergeared, then going to a smaller pinion will make the motor hotter, and you will need to go to bigger pinions until the motor runs at a good temperature(130*-150*) in a five minute run... Best is to ask the other pro racers at your track with the same motor about their starting motor setups for the current track layout, and go from there....Also make sure your car is right at the minimum weight limit to keep temps down.... Good luck....
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Old 11-12-2017, 11:26 PM   #5
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and a fan never hurt either.
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Old 11-13-2017, 02:00 AM   #6
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Quote:
Originally Posted by andrewd View Post
A Question

when my motor temp is high i am told to go down on my gearing

so if i am running for example a 78 spur and 32 pinion and a FDR of 4.5 do i go up a pinion or down a pinion or is the FDR up or down in the number

?????
What are your temps? 160f is safe in my book. 180f is the limit. As someone already mentioned, a quality fan can keep temps at bay.
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Old 11-13-2017, 01:07 PM   #7
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What are your temps? 160f is safe in my book. 180f is the limit. As someone already mentioned, a quality fan can keep temps at bay.
160F IS safe for sure. But what you failed to take into consideration is lots of drivers don't drive consistently. It means one time it can be 160F. Next time it can be 180F if they brake or slide around a lot. Then you fry your motor.
To be on the safe side, especially if the driver is not really consistent, I'd stay below 150F.
As somebody mentioned, sometimes too high FDR can make the motor even hotter. With 17.5T, I would not go anything above 4.8 FDR unless the track is ridiculously small.
The timing on the can affects far more on the temp than the FDR in most cases. If you cranked up the timing, start lowering that first and keep checking temp every 3-5 labs.
Making sure to use lower timing on the can in combination with low FDR and vice versa is always a good practice and you can work your way up or down.
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Old 11-13-2017, 02:27 PM   #8
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There are a number of factors that play into motor temps. Certainly timing and FDR, but also things like drag brake, driving style and track layout.

Do you have a fan? If not, get one. Still too hot?

Are you using drag brake? If so, that will add heat. In you search for cooler running, start off by removing any drag brake you may have. Then reduce teeth on your pinion, or run a larger spur gear until you get your temps under control.

Now, its time to experiment. If you reduce motor timing (like going from 45 to 40 degrees on the can), that will reduce temps and allow you to go back up a tooth or two on your pinion. Maybe you like the feel of a little extra torque from the lower timing.

Once you are in a comfortable temp range, play with the gearing and timing to get the feel out of the car you are looking. Then you can add back your drag brake, keeping an eye on temps. The more drag brake you use, the more heat you generate.
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Old 11-14-2017, 07:26 AM   #9
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Get a fan. Yeay racing offers some inexpensive fans that work well.
If you haven't had your motor professionally tuned I would recommend that as well. Sensor position and motor timing can be optimized to reduce heat and improve power.
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Old 11-15-2017, 07:04 AM   #10
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I bought one of those Amp checker thingies, but I cant remember where my amp draw should be....
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Old 11-15-2017, 10:56 AM   #11
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Get a fan. Yeay racing offers some inexpensive fans that work well.
If you haven't had your motor professionally tuned I would recommend that as well. Sensor position and motor timing can be optimized to reduce heat and improve power.
I use Yeah fan too and it's great. The motoring tuning for the amount of money you spend is not for everybody. I use $35 motor it's as fast as any expensive motor.
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Old 11-15-2017, 10:58 AM   #12
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ESC settings can be adjusted to lower motor temps also
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