I had alot of trouble keeping my 5700 cool in a slash. I added a motor fan (sorry BrianG) and aluminum trans a cut temps in half. I used ti hit 200f in about 10 minutes. Now it doesn't get above 105f.
Oh well, temps were back up outside today amd I was able to get the vxl motor up to 200 degrees after a couple 15 minute non stop runs using the 19/90 combo. Will try a 16t to see how it does.