I have a 13.5 motor in mine with a stage 1 fast gear set .. I don't want it to be to quick, it may fall apart

after all its only a £80 tub chassis.
My only concern is being rammed up the derriere by the 7.5t lads
Not that i'm concerned because I don't cheat, but how will you tell if they are not running to the rules without scutineering the cars and checking?
Scott.