Inside the stock exhaust-a few pictures

[Jimmer]

I entered from the head pipe with a borescope.After the mid section 90 is a "funnel" that attaches to the internal stinger.It is supported by the round plate with several large-ish holes at the convergence cone.The middle [3rd] picture is looking at the stinger through the support plate holes.In the last picture you can see some of the silencer packing/perforated steel.Gordon Jennings was one of the first to experiment with the internal stinger.He found out it knocked down a lot of noise without killing performance.

 

[Jimmer]

I thought there would be WAY more interest in this! I had a hunch there was a lot going on inside the stock exhaust.Sure enough,there is.I have two mods I will do to the stock exhaust and try it.I may find a neat combo and learn something.Or I may waste my time and energy.Only one way to know for sure........

 

[Blaaster]

I am interested to see if you can modify it for some power gain!

 

[bansheedave]

Personally, I would gut the stock pipe and call it a day. Any noise increase will be nominal and the sonic wave inside the pipe would increase causing better overall performance. All that garbage inside reduces the sonic wave making the motor performance low for beginners. Couple that with the high squash band and poor head design.

 

[Larry's Shee]

I thought there would be WAY more interest in this! I had a hunch there was a lot going on inside the stock exhaust.Sure enough,there is.I have two mods I will do to the stock exhaust and try it.I may find a neat combo and learn something.Or I may waste my time and energy.Only one way to know for sure........

What? Been 115 views. I'd have kept my stock pipe to "experiment" on if it weren't for a crack on the curved headpipe. Can't tell from pics, but there is also perforated metal inside. My thought would be to gut that out, cut the portion that necks down between front and rear cone and replace with straight or shorten it that amount.
Would be lots of work and welding tho.

 

[Surrey blaster]

I have my old stock exhaust just sitting in th shed so might try and open her up at the weekend and gut her out

 

[Jimmer]

I cut mine open yesterday.Good picture of inside stinger located at the convergence cone 90 degree and double wall perforated sections.

 

[Blaner]

Interesting thanks, now to cut up some aftermarket ones and compare...

 

[Surrey blaster]

I was going to cut down the seam, gut it and get it welded back together and see how she performs

 

[jus_me]

No need to cut up a good aftermarket pipe. There is nothing inside of them.