Silencer repack and modification

I've been into mine recently, and I was pretty conservative about it. I have a 2011 FE 570 S, and the factory exhaust reminded me of a sewing maching. I could tell by listening that it wasn't breathing right, so I resolved to incrementally make modest modifications until I got what I wanted.

The first challenge was to get the end cap off. It's silicon-glued in place very thoroughly at the factory. I removed the five screws and ran an ex-acto blade around the bead in an effort to get break it free, but that wasn't enough. Bergman suggested a broomstick up the tailpipe to provide more leverage. I had a dowell the proper diameter, and it worked like a charm.

Once I got inside and examined it, I found that the tailpipe (which comes off with the end cap) sticks into a concave pocket in the inside of the can. The result is that the gasses have to make two 180 degree turns to exit the can. I measured how much the tailpipe sticks into the can, and decided that for the first increment I'd only remove 1/8 inch of tailpipe. That's easily done with a hacksaw. Then rather than leaving the end of the tailpipe blunt like that, I rounded the end inside and out to promote smooth gas flow.

When I put it back together and rode it, it seemed like a good improvement. The engine responded well to throttle inputs, the change in sound indicated that the the gasses flow more easily, and it was a little louder and throatier. I can easily cut off more of the tailpipe in the future, but I think I'm reasonably happy with what I've got at the moment. I don't want it to be so loud that it calls attention to itself during road sections.

Hi

I did this

viewtopic.php?f=5&t=14014&p=117370#p11737

:cheers:
ZAGA

the link to my pic is broken in that thread

here it is

its a bit of stainless tube with holes drilled in it you could also just use some perforated exhaust tube or even gut the whole can insides and run a new perforated tube right down the middle.

FWIW my comments regarding the cans performance and cams etc in those threads were for the 100mm bore. the 105mm bore likes big valves a nicer cam and the lighter less restrictive Ti Akra muffler