TOPIC:

Guys - I need some help to understand something better. Below are two aftermarket baffles, avalable at DennisKirk.com and others.

The first one, I understand. The exhaust enters the front of the device, is slanted across and pushed out the little holes back into the main section of the pipe. No prob. Some baffle, and the exhaust does not go straight through.

The second one I don't get. Is all that is does is just make a the outer edges of the pipe bumpy? It appears to not be blocked off at aither end, so I don't get how it baffles at all? Does it just let the exhaust stright through?

Thanks...





Post edited by: Biquetoast, at: 2006/12/17 23:23

The second one is pretty much free flowing yeah, but exhaust isnt a steady flow, it comes in pulses. what I believe happens is the pulse of air gets shoved through the holes into the can as well as straight out, so not all of the exhaust gas goes out at the same time. once the pulse passes through, the now pressurised can shoves out the air that was pushed into the holes, and it exits the pipe just after the original pulse, breaking up the pulse a bit to lower the "noise" level
my $0.02
Scott

77KZ650 wrote:

...pulse of air gets shoved through the holes into the can as well as straight out, so not all of the exhaust gas goes out at the same time...

Thanks for the reply.
You mention "can", but this is intended to work in a straight pipe, yes? So the air kinda' gets caught by the tabs, cycled back in the pipe a bit, and then released, right? Boy, that really doesn't seem like it would do much.... I would imagine it's pretty freakin' loud... almost pointless....

Biquetoast wrote:

77KZ650 wrote:

...pulse of air gets shoved through the holes into the can as well as straight out, so not all of the exhaust gas goes out at the same time...

Thanks for the reply.
You mention "can", but this is intended to work in a straight pipe, yes? So the air kinda' gets caught by the tabs, cycled back in the pipe a bit, and then released, right? Boy, that really doesn't seem like it would do much.... I would imagine it's pretty freakin' loud... almost pointless....

It really isn't the "air" that's important in this case, it's the exhaust pulse *waveform*. Essentially, it reflects a portion of the exhaust pulse energy (phase shifted) back against the original direction of travel, cancelling out some fraction of the incoming pulse's energy.

I'm using the second one in my bike which had a straight through silencer. Before it was pretty loud as you would expect but with the baffle in it just quietens it down enough to be sociable . Its still reasonably loud but im not likely to get pulled by the Nazi cops around here.
The first one would have an even greater effect on the noise but probably at the expense of power.

I'm using the second one in my bike which had a straight through silencer. Before it was pretty loud as you would expect but with the baffle in it just quietens it down enough to be sociable . Its still reasonably loud but im not likely to get pulled by the Nazi cops around here.
The first one would have an even greater effect on the noise but probably at the expense of power.

Opps I pressed the "back button which cause the double post. Sorry

Post edited by: GPzephyr, at: 2006/12/18 17:14