Exhaust

[Boneswig]

Before everyone shoots, I am asking because I don't know. So I mentioned before that I am opting for a 2-1 type exhaust system where 1 and 4 is connected and 2 and 3. Did a bit of reading and got all confused about everything, so turning to my more learned XS members. According to what I have read the muffler is the important part (No Sh*# sherlock) but then the move on and say the thinner the inner tube (perforated tube) the better performance and audio you wil get. WTF! So if I place a half inch innertube inside a 2 inch pipe with glass packing I will have both of best worlds? Not making sense because in the back of my mind it rings RESTRICTION! This I found on about four different sites. Then I found another site with what I have in mind but think the back compression might damage valves or something. They running on a four cylinder system. Going down from two to one, then through a muffler (small one) but then here comes the odd part. They split back to two pipes. One getting feed from the outer of the inner tube and one from the inner of the tube. According to them this will give you a deeper thump per stroke because one pipe will be louder than the other and this creates some accoustic magic. So please give advice or input here. In short I would like to have two (per side) 2 inch stainless steel pipes coming out just after my swing arm joint. I would like to have sound but not a killer sound where my neighbours start swearing etc, so a nice sound but not a screaming sound (if that is possible). Awaiting your input and advice. Maybe someone knows how much psi back pressure a stock system has and can calculate it further from there.

[DiverRay]

for my 4 to 1 muffler, I used a 1.75" bit of exhaust pipe, 18" long, for the insides. I had to cut and weld a bend, and then I cut slots in the pipe, and on the engine side bent them down to force the flow outside the pipe. after the bend, the slots allowed the flow to go back into the pipe and out the end. No packing and it's not too bad.
For a 2 to 1, I'd go with a 1.5" by 18" for the inside, drill 1/4", or 6mm holes along 10" of the pipe. Leave about 1/2" from the back solid, and in front of the drilled part cut three slots, spaced about 1" or 2.5cm from the end, and 2" or 5cm from each other. the slot should be about 1/3 of the way through the tube, and then push down the center so it flows the exhaust up out of the pipe. Pack the last 10" of the pipe with fiberglass cloth, and call it good.
I can try and take some photo's if you need them, pm me.

[DiverRay]

OK, took some photo's of my setup. This is a Kirker 4 to 1 system, with the stock muffler shell and end cap. I built the "insides" to fit, and try and keep the noise down to a reasonable level.
Here are the photo's:
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Hope this will give you what you need to try and build your own baffles. IF the pipes are shorter, I would put a fender washer in the middle of the pipe to keep the "strait through" noise level down just a bit.

[Boneswig]

Absolutely awesome. Thankyou very much. Will send pics from my side as I build it. Might need your advise during the build. Thanks

[TADracer]

I did a similar thing with my 4-1 as DriverRay did. The stock baffle seemed very restrictive so I cut it off at the rear plate and then took a length of 1.5" exhaust pipe (same size as the down tubes on the header) and cross drilled a host of 5/16" diameter holes and braised it onto the rear plate. Then I fashioned a front plate to help keep it centered in the muffler and to force all the gasses through the pipe. Wrapped the outside with a very light layer of glass insulation (kind of like the old Cherry Bomb mufflers). Gives a nice throaty sound with no restriction.

Sorry, I have no pictures.

[Boneswig]

Much appreciated. Any input on this is helpfull. The bending and shaping is the easy part the part that was doing my head in was the muffler part of it. If all goes well ill be picking up my stainless pipes and bends this weekend and start fabricating it. I am thinking I am going to make several mufflers because they look so easy to make until you stand infront of the drill press ready to dril the first holes.

[motoman]

Motor IS happiest as well as the CV carbs thru ALL cruisin' rpm ranges with the
stock system.

[DiverRay]

We know, but if the stock system is gone, ya need to improvise! This will give some back pressure to keep the motor happy.

[motoman]

We know, but if the stock system is gone, ya need to improvise! This will give some back pressure to keep the motor happy.

Yuppers.......and thanks for the addition to my short response
Ray.