I race on carpet and high bite clay with a gear diff (usually 20k on carpet and 1k-5k on clay). I'm certainly not the fastest guy but I can hold my own. I've never really experimented with ball diffs because ....... well to be honest, I was sort of afraid of them. I did race a B4.2 back in the day but I was still a noob and had my buddies set everything up for me.
Anyway, I just recently purchased a dirt edition buggy (with a ball diff) and plan on forcing myself to learn. There is a great thread at the top of this section (
https://www.rctech.net/forum/electri...er-clutch.html) that shows you how to build and break in a ball diff. I followed this process on Monday and my diff feels buttery smooth.
I'm excited to compare the carpet buggy vs. the dirt buggy sometime.