Having the same issues with same set up as your's , blowing the tyres away on launch , next time out i'm gonna change front shock to 70/30 , maybe the front end is coming up to fast & not allowing the rear end to work hard enough , bit like the guy on the scales holding a 20ft scaffold board with his mate supporting the other end , when he tries to lift the board on his own the scales read his weight plus the board , when his mate helps him lift the board the weight on scales does'nt alter much........i read this somewhere before so it stuck in my mind , the guy was talking about higher hp motors sometimes need a slower rebounding shock on fronts.