The price limit on Spec brushless motors for use in BRCA competition is £90 - EB Rule 2.1. To race in the GT12 Nationals you must have a motor that is on the EB homologation list - link in Mark's post above - for 13.5, or a G2 brushed motor that is marked as such.
The Thunder Power Z3R-S Part # TPM-540A135 is on the list, but no other model of Thunder Power motor. HTH
