1940/7 getting hot...help?
 

Ok...so I've had my 1940/7 powering my G2R. Have ran it on everything from 4S to 6S and on 6S it gets a bit toasty but it's fine on 5S all day long. A full run through a set of packs at full race pace and I'm at 150*F.

I recently picked up a 1950/7 from another RCM member so I put the 1950 into the G2R and decided to use the 1940 in my RC8.2 that I got a killer deal on. At first I geared conservatively with a 13T pinion and it was definitely undergeared and temps were really high (165*F). So I jumped up to a 14T. Still felt undergeared but temps dropped to about 155*F. I then went to a 15T pinion and I came back from a track session to find it at 180*F!!! HOLY CRAP.

What the heck is going on here? I'm running it on 4S. How is it that this motor pushed around my bigger, heavier G2R but is having issues in an RC8?

Any input appreciated...

What would the difference in airflow be?

I have a 1512/3D (1700Kv.) that I ran on 6s in a Revo at race pace and only ~120F temps, then this year I moved it to a Durango DNX408T converted and the temps went up to 165F MIN, 185F MAX, I attribute it obviously higher loads, but less airflow and hence less cooling.

I am getting a 1518 Neu 1.5Y for next year, as one of the motor phase leads on the 1512 finally broke last week on the last race day of the year (lucky..)...as the motor was from 2007, yeah, it's been running reliably since then, awesome motor.

That could be it. There's very little airflow in the body. I'll try to add a fan (don't kill me Brian) or cut some vent slots into the body to see if that helps.