I believe its called a SET valve.

I am pretty sure if you replace the CAT with a straight pipe it goona be stupidly loud, will probably run worse (lean) without a remap. Look through the exhaust options post for more info.
You should be aware that most race teams are using a convential style muffler.

 

so basiclly if i was to run with no cat, i would need to get the bike dynoed?
not sure how bikes work but if the put the wideband sensor after the cat its going to read a little higer the if the but it before the cat


also what is the purpose of the set valve?

richie

 

According to the seasoned racers on here, the SET does nothing but keep noise and other emissions down to the legal limit. Suzuki claims it helps mid range torque... but no one has seen a dyno to prove it. 600's already run very lean so.....

 

Dont quote me on this but I think the SET is used like a EXUP valve and helps to pass emissions tests.
Also, I think the bike runs a lambda sensor to help adjust the fuelling again for emissions tests.

 

how can you make the set valve open all the time?

 

A SET valve is designed to physically alter the characteristics of the exhaust system. The valve is essentially a flap and is rotated to reduce or increase flow through the system. When closed or reduced, back pressure increases within the header portion of the exhaust system, changing the dynamic of the wavefront travelling from the exhaust ports, ultimately aiding in exhaust gas extraction from the cylinders. Your CDi is calculating the position of the SET based on your throttle position sensor and a host of other inputs to optimize the air-fuel mixture which should, in theory, maximize power at any given rpm.