Just before you run off thinking you've done the best thing by buying the Just Engines cheapo Hatori copy pipes instead of the original... there is a difference.
I bought the 1.40 pipe... it looks very similat to the original Hatori... infact some people can't tell it apart. I can tell you one thing... it's doesn't perform anywhere near as well.
It costs half the price of the original... The problem is that the original performs 250% better. It isn't just a RPM thing, it's about throttling and a smooth flat response/power line and finesse! The copy is far more on and off... sure you can play with the lenth for the season... but it's to avail... it isn't a class act.
Not that 99% of JE market cares... one presumes they just want on/off power!