yeah wheel chatter can be quite an issue especially if your on a very tight circuit and thats the type of circuit we would sometimes would run the 0 degree caster on the FK05, to counter entry understeer and usually with a little kickup on the front to help weight transfer also. The narrow axles work well to counter that problem as well.
Good result in the UK last weekend for the FK05 at the last BRCA Mod National. Darren Stlyes finishing 3rd in a really competitive field, car was working really well. Top 4 was
1st Chris Grainger - Yokomo
2nd Craig Drescher - Associated
3rd Darren Stlyles - Xray FK05
4th Andy Moore - Hotbodies Cyclone