Originally Posted by cwoods34

What tires and traction compound are you using? If the tires are too hard or the compound doesn't "agree" with the track, it could wear off halfway through a race. This'll make it loose and every time the back slides it'll cause more buildup on the tires, which only continues to make it worse. It may also help to clean the tires after every race if you don't already.

You might also not have enough "roll" in the back to keep bite on the rear tires. I've found that 1000cst is fast but can be a bit harder to drive on lower-grip tracks, or if the back isn't sticking enough.

I was having problems like you described yesterday, and it turns out I forgot some shims on the back arm mounts, so I only had about 1.5* toe-in! I went up to 3* and the back became too stuck!

Hope this helps!