TM KZ2 exhaust differences

What are the differences between the exhausts (if any) that come with the generations of TM KZ engines?

For example, is there any difference between the K9 exhaust and the R1 exhaust?

More specifically, will there be any noticeable power loss if I put a R1 exhaust on a K9B engine, compared to the original K9B exhaust?

I would compare measurements between them all. Should be public information just search up the homologation sheet for each engine