Ok so here is my situation. I have a Losi SCTE that I use for our local parking lot on road races. It has a Hobbyking 120a esc, a EXI D227F servo, a Flysky GT3B with Flysky receiver and run a 5000mah 2s battery. After about 5 min of racing my servo starts acting up and steers for a second and then goes back to straight position after it starts acting up it only gets worse and worse until I'm notable to race anymore. I changed the servo to another D227F thinking that was it and it was the same problem. I changed batteries on my radio for some new ones and same problem. I checked battery voltage when it started happening and my lipo was at 3.8v per cell so it still had enough juice. So what can it be?

I'm racing a SC8e with a AE servo and the same ESC, Rx/Tx that I'm using on the SCTE and this one does not give me any problems.

So need new ESC or what?

Buy a Novak glitch buster for your rx

^This. It'll solve 100% of your problems.

So why is this happening? I want to understand so it doesn't happen again with my other cars.

It's called a brown out. When the battery gets low and you pull a lot of juice it's causing servo to cut out. A glitch buster most likely will solve the problem but it could be bec on esc also. I have a friend that runs same esc and that was his problem the bec. I run the same esc in my scte and I have to run a glitch buster. It's basically a capacitor that stores power to keep it from browning out. Could be a cheap fix they are like $5. If its escs bec they run about $15-$20.

Yea the rx cap is the cheaper more convenient way to go, it's not guaranteed to work though, I ran a savox with a rx cap on my spektrum rx with a HW sct pro esc and it still had brownouts, I ran the same servo with my mt4 rx and tekin RS esc with no cap and didn't have any brownouts, both esc are at 6.0v, so seems to be certain receivers brown out easier or different escs are weaker to supply the rx the power under a heavy load

Ok cool thanks for the explanation. I ordered a Novak glitch buster hope that fixes my problem.

Here is the video of the race I lost yesterday because of the dam brown outs lol

You can see after minute 4 when my car is completely out of control

http://youtu.be/dK_HE0ZZ1R4

Haha yea dude that's bad, my old 4x4 sct would brown out at the end if the straight at sdrc smacking the wall full speed hahaha, hopefully the Novak cap will take care of it