I got some time yesterday and installed a new heat sink that I think will be more efficient while driving. I mentioned before the old heat sink below has the fins parallel with the controller, but the air while driving is perpendicular to the fins.
Here is the new heat sink attached to the controller. You can see the mill work done so the bolts are recessed now and touch the thicker base of the heat sink. This allows for more consistent torquing than before and should allow for better heat transfer. Don't forget your thermal compound when installing any heat sink. Thermal compound greatly increases the heat transfer
I wanted a better way to attach my temperature sensor for the controller. I made a little L bracket that attaches to one of the bolts.
Here is another shot with the sensor attached. I'll try to do some temperature comparisons next week, but with the increase in temperature just over the weekend it may be hard to get any reliable results.