Do I Need A BEC?

[hoovhartid]

I recently purchased an Associated TC4. I run it on a small track using a Sidewinder 4600 (CM-36) combo. After a few turns (less than 1 lap) The ESC is cutting out and shutting off. What gives?

Should I have bought the Mamba Max instead?
Do I have a bad ESC?
Do I need a BEC or what?

I know you can't answer yet. So here's the rest of the story...

When I first got it, I was running a 75t spur (largest) and a 20t pinion. This was good for about 2 laps before it hit about 190-200 deg F (Motor and esc) So I geared it down to a 19t pinion...still no good. It would shut down after a few laps. I didn't have a smaller pinion at the time so I called it a day.

I put in an order for some more pinions and the Associated Motor Cooling Duct/Fan Kit(trying to keep it cool). When it came in, I went to an 18t pinion. I went about half a lap and the car turned hard left, slamming me into the guard rail and shut down all power OK...now I'm pissed. After replacing My front A-arm and my rear axle carrier...I powered back on.
Now get this... at this point, I put the car down and turn the wheels back and forth a few times and it happends again. The wheels turn hard left and I lose all power to the car! I don't think the sidewinder can power the Rx the fans and the servo. Am I expecting too much? I took the car home and let it sit a few hours. I then turned it on, moved the wheels back and forth for about 5-10 seconds and got the same powerdown. (wheels turn hard left and esc is nonresponsive) The Yellow light(middle) is solid and the two lights on the sides of it blink/beep every few seconds.

If I unplug the fans, Everything seems to run a BIT better. I get high temps tho. 155F ESC and 165-175Motor. Also It seems that when the ESC temps get high, my steering becomes sluggish.

At this point, I'm just wondering what my best option is.

Do I send in the ESC?
Do I Replace it with the Mamba Max?
Do I buy a BEC?

Here's the full set-up;
Associated TC4 75t spur 18t pinion
Castle Creations Sidewinder 4600 combo
Associated Motor cooling Duct/Fan kit #31037
Spektrum z590 servo
Spektrum sr3500 spm1210 3ch micro Rx
Spektrum DX3.0
Zippy-K 4300 20-30C Lipo 11.1v 3cell

Thanks for reading all of this! Sorry 4 such a long post but I wanted to give all the info before I asked 4 help.