Originally Posted by
SteveP
Yes there is. In the case of the Sirio pipes, the 2013 on-road and off-road pipes are completely different. The on-road pipe is considerably shorter and has less volume. It's made for an engine that runs at much higher RPM and that has more advanced timing in all respects. I can't speak for other brands, but there's definitely a difference with the Sirio, Werks and Trinity pipes.
Since they are different why would they have the same EFRA number? That is what really gets me confused.
Wouldn't they have changed the number since the pipe is different?