Expansion chamber modification

[A.Holley]

Apart from fitting my 4LS front brake, I decided to try and take the sting out of the noise from the chambers on my T500
Yes, I am getting old.
Have done some research over the years on moving the stinger pipe up inside the chamber so that it starts at largest diametbof chamber., people such as Gordon Jennings recommend the idea.
I bit the bullet and decided to try it.
Same diameter ( 25mm) but had to lengthen a bit to get it into the belly of pipe..
Apparently, by doing this, the gas is bled off from an area of much lower pressure which decreases the noise level
The stinger is only a pressure bleed so doesn’t really care .
Despite being a bit skeptical , I was delighted with result. Without the end muffler it was quieter than original set up with muffler. And with muffler fitted it is barely louder than a standard set of factory mufflers.
The seat of the pants dyno has detected no difference in power.
Don’t need to wear ear plugs on longer rides now, so acwin all round

Andrew Holley
Dubbo
Australia

[badgereng]

Great info! Glad it worked out for you.