Do you think a 670 cc 2 stroke would be able to breathe through a e series muffler with 18 discs ? How would that effect the pipe reversion ? has anyone tried it ? Goal is to make a 2 cyl. 2 stroke forestry approved and below 98 db . I also thought maybe the stock ds can with a 1.5 in hole outlet , but retaining the stock spark arrester inside . Any suggestions would be appricated !

 

any ideas ??????????????? input ???????????????????

 

What was bolted on that thing in its past life? Think that way for an answer.

 

It is a snowmobile engine with a muffler the size of a small duffel bag . Thats why I would like to try to put an atv silencer on it .

 

Hey Ben
Try talking to Eric over at EJR technologies.
He is AKA "The Boss" on our forum.
He might be able to point you in the right direction.

 

Bell,
The pipe on a 2 stroke plays an important part in the power curve and the power output. There are websites dedicated to this theory that can help you understand where you want your power band and how to design a pipe to put the power band in that range. Exhaust porting plays an important part there as well and the pipe must match the exhaust porting to maximize power in a given range. It is a science and short cutting it will result in unhappiness with your ride.
The snowmobile conversions that I have seen in the past have used custom made pipes or altered pipes from other bikes. Considering the volume of exhaust flow from a motor that size, I can see why the original pipe was so big.

 

Bell,

Where your running a dual cylinder, I am assuming you are also running a dual exaust and not the 2 into 1 type of exausts. If you are running duals you might could finagel a Toomey hush kit 2.5 . They are made to fit there banshee pipes but it sounds like your a fabricator if your doing this custom bike so you might be able to make it work. try toomey.com

 

670cc Ski-Doo motor needs to run in the pipe that came with it OR a pipe manufactor for the sled. Try Crank Shop pipes, Jaws pipe, or Dyno Port. I had a Summit 670 X back in 99'

 

AAen is gonna make me a single pipe , just reconfigured to fit the polarass chassis , and to the same dimensions as the stock pipe . my problem lies in how to make it quiet and sparkarrested and not loose alot of flow . the stock sled outlet is only about 1 1/2 -2 in dia . With the supertrap style and use 18-24 discs it might work , but my concern is in the backpreasure and altering the pipes reversion .

 

I like the toomey idea .that would work , but twin pipes are very expensive !