Exhaust End Caps - Ktm Supermono

[agent34]

Gents,

I must commend you on your website it is full of great info. I have a few questions relating to the KTM 640.

Presently i run a supermono factory exhaust, does any one know if the end cap ( thats the hole size at the back) is changeable to a bigger size diameter? - if so where can i get it ?- how does it change the power delivery ?

Most of my racing is done on the road race circuits where the engine revs are consistently in the high rev range for extended periods.

Also is there any dramas with fitting the Flat Side yourself and do you have to get it jetted/ dyno, or just a matter of this goes with that and that's it.

Also has anyone popped the forks up through the top triple clamp to change the weight/steering of the bike and how much is that measurement? and what happened - high speed wobbles, faster turn, loosing the front end.

Santa is bringing a Fat Flat Side for Christmas. :)

[Sibbo]

Presently i run a supermono factory exhaust, does any one know if the end cap ( thats the hole size at the back) is changeable to a bigger size diameter? - if so where can i get it ?- how does it change the power delivery ?


I am assuming the perferated pipe is the same diameter as the end cap. So by changing the end cap, you would not do much, as you are only affecting a few cm of pipe. You would need to change the perferated pipe as well, then you will change where the power is delivered, either high/mid/low. But if you go too much larger, you will create some bad things with the flow from the header into the muffler.

The easy way to know what to do, is copy a name brand aftermarket pipe/muffler for your engine.

[discobob]

Droping the forks through on the KTM is not a great idea, you will get more chatter than you maybe getting now. The best thing for these is a different triple clamp with differentt offset around 14mm worked well for me. KTM make that clamp for the EXC450 etc but not sure about 640. If you can get these clamps the bike will be more stable in a straight line and generally handle better in the corners

[agent34]

Thanks for the info, on the pipe it makes sense i just needed somone to tell me that prior to tearing it apart, looking down the end and then going what the F@@K did I do that for, you have wrecked a perfectly good slip on, you idoit, DOH! :x

At the moment I am considering the options of a suspension upgrade, valves, and settings. I have experience the chatter you talk about and it was one of the things that led to the question on suspension. I rode with a guy at Oran Park who had done this dropping of the suspension through the forks.

Do you know how much the triple clamps are that you mentioned. ? :D

[discobob]

I think the KTM hard parts triple clamps are aout $1200 from memory