exhaust splitter Harley Exhaust Discuss exhaust splitter in the Harley Tech & Harley How-to forums; Sometime in the last year, AIM, I think it was Tom Johnson, wrote an article on the advantages of an exhaust splitter. It was simply a bolt near the exit ...

[softail66]

Sometime in the last year, AIM, I think it was Tom Johnson, wrote an article on the advantages of an exhaust splitter. It was simply a bolt near the exit of the pipe to redirect the gases. I would like to install this in my current pipe, supertrapp 2:1. I previously had V & H 2:2 with the Big Thunder baffles, which was basicly the same thing. I liked the tone and performance of the BCT, but it was just too loud for my old ears. Does anyone remember which issue the splitter article appeared in? I have searched my old issues of AIM, but can't find it. Buzz?
Thanks

[eglidemike]

Hey softtail 66. The article you are looking for, I believe, is in the Sept 07 issue, page 188, Dyno Dilema. I have been considering the same thing for a set of straight pipes on my electra glide. Good luck!

[94flhtcu]

That supertrapp uses discs to add back pressure, doesn't it? I don't think this is meant for your system.. But, it'll help those straight pipes on that bagger, for sure.

[softail66]

Yes, the supertrapp has 20 discs on the endcap so you can vary the backpressure and the sound. I started with all 20 and now have 15 discs installed. I thought with the splitter in front of the discs, I could better fine tune the backpressure and the sound. I also would like a deeper tone, which I had with the BCT baffle, which is almost identical to a splitter.

[HarleyCruiser]

Originally Posted by softail66

Yes, the supertrapp has 20 discs on the endcap so you can vary the backpressure and the sound. I started with all 20 and now have 15 discs installed. I thought with the splitter in front of the discs, I could better fine tune the backpressure and the sound. I also would like a deeper tone, which I had with the BCT baffle, which is almost identical to a splitter.

The purpose of a splitter is to create turbulence on straight pipes to break up the sound wave, and help prevent reversion.
Reversion is when the sound wave go out the end of the pipe, and expands and the expansion creates another wave that goes back up the pipe. If it reaches the valve when it is open it traps the exiting exhaust inside the chamber.
If you have overlapping valves the reversion wave can even come out the intake and mist out the carb.
When you get this you get a flat spot on acceleration, it is like a bog, but there is a difference.
The splitter does not create back pressure, it does not quiet the exhaust.
It is of little value on pipes with baffles.
Creating back pressure does nothing but choke the sound wave, and quiets it, reduces flow, and you loose power.
Especially on drag pipes.
You need to break up the sound wave and still have good exhaust flow, this is why the best exhaust have an expansion chamber and baffles.

[47knuck]

I once read about an old Panhead Buzz had in Daytona with straight pipes (don't ask!) and he took it to a dyno tuner who drilled near the end and put in a simple bolt and nut in each pipe and picked up a couple of horsepower.

That was a long time ago but I still remember it.