v-twin exhaust

been thinking about making a chamber to replace the original muffler. then running a pipe to the back.

anyone know if the two short pipes dumping into the same small chamber would be a problem?

By small chamber what size do you mean? 2 liter bottle? Milk jug? Doc Sprocket  (Sprocket's Garage) on youtube has an interesting V twin exhaust. 2 pipes go full length into a chamber in the back. He has the option of removing two pipe caps to add some volume.



I think what you are talking about would definitely sound better than stock if you used no baffles and a large diameter pipe(like 2-3") going to the back. I think it would sound pretty badass, haha! Good luck!

Yeah like Rich said if you used a large diameter pipe as like a resonator it would sound pretty awesome. It would give it like a deep "thud thud thud" when it was idling.

RichieRichOverdrive wrote:

By small chamber what size do you mean? 2 liter bottle?

yes about 2 liter bottle size. have a old fire extinguisher thinking of cutting a section out of the middle just enough so it fits in the front some where and some how. then weld the two short pipes in the side and enlarge the hole at the end to what ever size the single pipe will be. don't want to go to big and loose low end torque. at the end thinking maybe another chamber for sound but may be over kill.

not sure if the chamber up front would be beneficial like a x-pipe on car exhaust or a problem because to close to the heads.

Mower engines don't need back pressure. They're not 2 strokes. This has been confirmed before. And if you could set up the pipes sort of like headers on a car, you will get a slight performance boost from scavenging. The exhaust pulses will pull each other along resulting in less work needed to push the separate pulses along. It doesn't really matter though. As long as the exhaust isn't really restrictive it'll be better than stock.

Should be fine. As Rich said back pressure is a preformance boost for 2-stroke engines only. This is because in a 2-stroke the incoming fuel/oil and air push the exhaust gases out after combustion, which results in some of it being wasted. If there is a bit of restriction -"back pressure" the fuel and air can be held in the cylinder and burned. This doesnt work for 4-stroke engines obviously becasue the piston is used to put the exhaust gases out on the exhaust stroke instead, so exhaust restriction will hinder performance. Im not a 2-stroke guy by any means so I'm not positive but I think thats correct haha. Either way a slightly larger diameter header pipe should work fine. I used a 1.5" header pipe for the 11hp flatty on my rat rod and it worked out fine.

Your 2 pipes dumping into your chamber/fire extinguisher would be fine. Even if you use your original pipes which would be 1 inch pipe I think.. The chamber would slow down the exhaust and as a result will quiet it some. Then the exhaust would speed back up going into the pipe to the back to a second chamber. When entering the second chamber in the back would slow down again and quiet it a little more. Then speed back up to enter the tail pipe and out it goes. The chambers will quiet the exhaust even without any baffling. The baffling would quit the exhaust more. Use piping that is same size or bigger then the original You don't want to go smaller at any point in the system, as it will choke the flow. By starting from original size and staying to that size, keeps it moving at the same pase. When you gradually go bigger on exhaust, It slows it down a little and ensures it will keep moving in the exit direction by expanding the gas, A good example would be- 1 inch off engine to front chamber, 1 1/4 inch pipe from front chamber to back chamber, 1 1/2 pipe for the tailpipe coming out the rear chamber to exit.

found this on youtube it is a series of videos.