captain
ArboristSite Lurker
I have a jonsered 2159 with a 20" bar and a non cat muffler. Been checking out AS for some time now and have done a pretty thorough investigation with the search function on the 359/2159 muffler mod but still have some unanswered questions. I currently only plan to modify the muffler, no porting yet. Hopefully someone can help.
1) I have read that the size of the exhaust outlet(including the stock opening) should equal anywhere from 85% to 150% of the size of the exhaust port....... That is a very wide range.....Is there any consensus of what is ideal and what can be expected besides it being louder with a larger opening, at what point does torque drop of....
2)Actual quantitative performance gains???? In reference to my first question, is there any data on actual HP, torque, or cut time gains per the size of muffler opening?
3)Spark arrestors effect on opening size? I understand that the average spark screen covers approximately 40% of the opening. When calculating opening size should you +or- 40% depending on if you have a spark screen or not?
4) When calculating the size of exhaust outlet opening, I understand one should include the stock opening. Mine has a deflector over it, How big is the stock opening????
I think that about covers it, any help would be great
1) I have read that the size of the exhaust outlet(including the stock opening) should equal anywhere from 85% to 150% of the size of the exhaust port....... That is a very wide range.....Is there any consensus of what is ideal and what can be expected besides it being louder with a larger opening, at what point does torque drop of....
2)Actual quantitative performance gains???? In reference to my first question, is there any data on actual HP, torque, or cut time gains per the size of muffler opening?
3)Spark arrestors effect on opening size? I understand that the average spark screen covers approximately 40% of the opening. When calculating opening size should you +or- 40% depending on if you have a spark screen or not?
4) When calculating the size of exhaust outlet opening, I understand one should include the stock opening. Mine has a deflector over it, How big is the stock opening????
I think that about covers it, any help would be great