Mr. Christopher beat me to it. Forgive my frustration when people say things without checking their facts first...
BRCA 12th Section members have grasped this nettle and sorted it - ProductionCup is now the same chassis as SuperCup but with a 17.5 motor. This was in response to the recommendation from people who race at clubs to give a slower car, not a cheaper car.
The point raised was that it was speed that was the requirement, not having a chassis with very tight restrictions that didn't handle that well - having ProductionCup as a kit-standard class with no leeway on parts and no diff.
This has been answered by having ProductionCup as a kit chassis with mods and a diff allowed. This means clubs can adopt this class and drivers wanting to progress can g to SuperCup by just changing their motor.
As Mark says, clubs can also pick and choose the BRCA Construction rules why want to adopt and then add their own variations. I hope that answers the point. Your drivers can all run in ProductionCup with a change of motor which you could phase in as I suggested in an earlier post. HTH
