Originally Posted by
DS Motorsport
An engine will wear out faster in a lighter car, since it spends more time in high rpm's. And we all know rpm's kill engines. With a lighter car the engine has less resistance to spool up and spends a longer time at higher rpm's since you can accelerate earlier and brake later.
When you limit the size of the exhaust port you will automatically set the maximum amount of rpm's in a way, not exactly.
However the tricky part is, how are you going to police this rule?. It's not possible to disassemble every engine to check the exhaust port size.
In the past the 235mm had rules about a maximum height on the intake and exhaust ports. Due a different bore/stroke messurement, cutting edges of the piston and changing crankshaft timing there was still a way to get more performance out of the engine.
A different force will come up. A faster acceleration does give higher forces as wel. The faster spin up of the crankshaft does give more stress on the rod and not only the high rpm. (most engines do fail when they are in midrange accelerating to topspeed). This item will not be changed with limiting the RPM by a lower/smaller exhaust port although the lower top RPM can compensate the lifespan.