Michael,
The class is in theory to be run to the rules of the new BRCA Clubman series, whenever they get published

With that in mind, and especially if anyone intends taking part in that series in the Summer, I would recommend getting a motor that appears on the BRCA homologation list of 17.5t motors (
http://domain3190026.sites.fasthosts.co ... %20pdf.pdf). Currently there are only 4 motors on the list and all allow (I think) adjustment of the timing, although speaking to Roger on Saturday it seems that some other motors have now been submitted to the BRCA Electric Board for inclusion in the list.
Currently, I am running a cheap (£45) Speed Passion UltraSportsman unit that has fixed timing (and not on the BRCA list), and it would be interesting to see how it performs against higher spec (and more expensive) motors, although the speedo will probably have more of an effect. Chris Forest has an LRP motor on a Tekin RS on "Spec" or "Stock" mode, and when we compared RPM of our respective motors he had the edge of just a few hundred RPM (mine was in the 19,000's his in the 20,000's), which probably won't make a blind bit of difference on a 3 to 4 second straight
Ian