Everything explained by Madulla, I would say!

@Madulla: When running the 3Racing diff, how do you built it up?
Leave out 2 shims, maybe? Any recommendation on the oil?

From my first use, I guess mine was still too locked. I had problems on a large high speed curve simply spinning out at full speed at the middle of the curve, nearly 6 meters after turning in.
Run the same track before with ball diff a month ago without problem...

BR,
Matthias