Today I took 30 minutes off of work and headed to Just 4 Fun. Luckily, they had several pinion gears in stock, so I bought a few of them.
When I got home tonight, I first started with the theory that I was undergeared, and slapped in a 23t pinion. Well, that didn't work, as within about 5 minutes my temps were BLAZING hot. So I let the car cool down a bit, then swapped in a 21t pinion...which is what I thought I was having good luck with before. Again, it ran good for about 5 minutes, but after that started to get a bit into the "dangerous" zone of the temperatures.
It was then that I found out that I had probably been measuring the temps wrong all along. See, ever since I had the heat issue with the timing, I've been taking the temperature by basically just shoving the temp gun right onto the motor. Before, I had been aiming it at the motor, and I believe I was "missing" a bit, as at such close proximity the laser actually shows you a spot slightly above what you are measuring. So I had been measuring effectively what was "under" the motor...and not getting good readings.
So I switched everything out to the 17t pinion, thinking that if gearing higher wasn't working, maybe gearing lower would.
To my satisfaction, I got very good temps with the 17t pinion. Not only that, but the truck also ran better for what I use it for on the track. After 5 minutes of running I was at 135 degrees. After 10, about 145. After my entire 3500mah battery, about 155.
Those are VERY good temperatures, and I definitely think that I'll be leaving the 17t pinion on there. I MAY try to gear it back up to 18 or 19 once I get my fan on the motor, but I like the way it drives so much at 17 that I will probably just leave it there.
I'll be testing it once more tomorrow, just to make sure that I am still seeing those same types of temperatures...but I'm pretty sure I've got it all figured out now!!!