Kawasaki Sportsbike Riders Club - Australia - Online Forum

G"day I have just bought a 2009 z750 and wanted to know why kawasaki have spent so much time on designing the muffler with that power valve and the rest of it, and would it really make any more proformance if i fitted a after market one. I feel that the std would be the way to go but would like to know what doe's the std muffler really do with that valve set up, it has to work?
Regards Darren first timer on site

Darren,

In a lot of ways you're right in as much as the bike is designed to work with the stock muffler and will work well. As I understand it the valve is designed to improve low-rpm torque, although often such valves are also used to create a "dip" in noise and emissions at the appropriate revs where these things must be measured. The reason most of us remove the stock pipes is that they don't sound as good (loud!) as an aftermarket pipe, and often look rather ugly. We like to claim that the extra hosrepower available by freeing the engine up is all utilised, but alas on the road most of us would never get close to taking advantage of the extra power.

If you don't mind the look and sound of the stocker I'd stick to it and spend your hard-earned on rider training instead.

BTW, welcome to KSRC!

It's also not always true that a stock pipe will add power, it can sometimes reduce power (especially if not getting it mapped afterwards, but I think this is not much less common with newer bikes?) and can move power around. My pipe lessened my low end and slightly improved my high end.

Thank you for that I think I will leave it std and just enjoy the bike for what it is and yes it is a bit ugly , the power it makes is a lot different to a vee twin I will have to get use to riding in the higher rev range I found that above 5000 rpm it starts to really have ago and is where the fun starts. Any way thankyou for the info its what i wanted to know.
Darren