I was wondering if anyone did a mod. that included saving their exhaust valve with a slip-on? (ex. cutting it off the stock muffler then welding it on the slip-on.)

 

No leave it on the stock exhaust and tuck your cables next to the battery box using a zip tie and dont worry, It wont hurt it except run a little rich (more). A power commander will help that.

 

I know that you don't use the valve with a slip-on, but what would happen if you incorporated the valve with the slip-on? Would mid-range be better than with just the slip-on?

 

i dont know i justdid my slip-on install today and i removed the cables from the servo totaly they are in the pile of parts i took off the bike. i dont like zip ties on anything if i can remove it. sounds much better now with the stock pipe gone in favor of a m4 slip-on!

 

i am sure if you were to "add" that valve to an aftermarket pipe it would work the same and your exhaust would be slightly quieter at low rpm,

Correct me if i am wrong but the valve is there to close off at low rpms to help build back pressure, giving your more torque from dead stops. so leaving it doesn't sounds likea bad idea, but it is these sort of factory items you are trying to get rid of by installing the aftermarket pipe because it is going to restrict your airflow on the top end where you want more response,

 

I know why manufactures put it in their bikes andthey wouldn't spend hundred of thousands of dollars on research and development and not implement it on their bikes if it didn't work. Almost all dyno runs I've seen has a lower power rating in the low rpm range with a slip-on compared to stock. I guess no one has left the valve on with a slip-on yet. I guess I'll be the first to try it. Thanks for the input.

 

to me it seems like all you gain by adding the valve back onto a slip on would be the low end torque, The rest of the power band will be lower, To me the pros of welding it back in won't outdo the cons? I think it is going to restrict to much air flow to get any real gains from the slip on, Basically it will just be a loud "stock pipe". the bikes run rich so adding the valve just means a little less throttle when moving from a dead stop.
But i am by no way an expert on the subject. But wouldn't it be the same as adding fancy chrome tips to a stock car exhaust?Change sthe look and maybe the sound but not the airflow?

 

How does the valve restrict air flow when the valve is the same O.D. as the I.D. of the pipe? and opens to a full 90 at 6000 rpm? Also the weight savings of a slip-on isof greater benefit being an under tail canister. Being that I have one of the sexiest bikes, It's all about the glam now, I'll never be above 6000 rpm all the time on the street, but having the most power the engine canproduce at the lower rpms would benefit me most.

 

Your kidding right? It may be open at 90ยบ but it doesnt disappear.

 

anything that doesn't allow air to flow in it's natural state will effect it, Thats one reason people polish headers and manifolds in cars, just creating a smooth surface will help over a tube in is natural state.

So removing a metal disk rivited to a rotaing bar and hinge will obviously help air flow, when you take off your stock pipe you will see it. It isnt very small. Picture air moving through a pipe almost the same as water flowing down a river, if it is rocky you will create turbulence, if it is nice an smooth, water (exhaust gases) will flow much easier and with less resistance. nice straightlines.