[Graham]

For class B and C in the winter rally, is the motor based on the make body shell used or or can you upgrade the motor type?
For example: if I run a Scalextric shell with aftermarket chassis, am I stuck with using Scalextric s-can, or can I upgrade to any other make of s-can motor NSR etc?
Cheers

I think on reflection that I might change the "Modified " class to be either a standard or another of the same same brand or upgrade to a  Scaleauto Tech 1 type (20k rpm ) motor.  I don't want to give this class the same status as for open, but limiting an upgrade to the same Scaleauto motor (rpm) seems a good compromise.