jonsered 2159 muffler mod

[captain]

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

 

[StihlBoy440]

I have modded one muffler on a 359 and it worked well. I started off with a non-cat muffler and proceeded by taking out as much of the internal baffle as I could without sacrificing strength and then I made the extra port where the bracket that mounts the muffler to the body is. I cut a rectangular hole in the bracket in between the 2 bolts holes and then proceeded to match the muffler up to that hole in the bracket, you can mount a spark screen between the bracket and muffler using the bolts to secure it.

 

[captain]

C'mon Guys......there has got to be a little more input on this project. I want to start this thing and become a true "arboistsite purist" with a modded muffler!!!! but do not want to just drill random holes in this thing.

Any help would be greatly appreciated.

 

[manual]

what ever you do don't just drill holes.......
80, 85% is great gains on a stock saw.
IMO any more is just noise.
Now do some porting that would be a different story.

 

[manual]

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.


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)I think that about covers it, any help would be great

yes

 

[SawTroll]

85% of the exaust opening from engine is a good starting point, as far as I know (never felt the need to do it, so it is just theory to me)...

..not 85% more than the original opening (more in most cases, I believe).....


... but, I could be totally wrong, as I have no experience with it......

 

[sawinredneck]

Yeah, 75-85% and you are there.
Take the deflector off, open the hole that size, buy a stainless steel strainer, cut the wire to fit and use some small self tapping screws to seal it up if you are worried about things geting into the motor.
Find some thin wall tubbing the size, or close, you need, probably take two of them, cut you're holes and weld them on. Again, you can use the strainer and stainless wire to hold them in place for screens.
There are lots and lots and LOTS of ideas and ways to do this. Do a search again, don't look for you're saw, look for ideas!!!
Me? I'm lazy, I drill holes, but it works!!!!:hmm3grin2orange:

 

[manual]

Exaust opening from engine + 85% is a good starting point, as far as I know (never felt the need to do it, so it is just theory)...

..not 85% more than the original opening (more in most cases, I believe).....

OK 85% total opening of exhaust port.

 

[sawinredneck]

Expect 15-25% gains in power when tuned properly, maybe more on that saw.

There is a number for you, OK?

 

[SawTroll]

OK 85% total opening of exhaust port.

You quoted me before I corrected my post........:biggrinbounce2:

 

[manual]

Yeah, 75-85% and you are there.
Take the deflector off, open the hole that size, buy a stainless steel strainer, cut the wire to fit and use some small self tapping screws to seal it up if you are worried about things geting into the motor.
Find some thin wall tubbing the size, or close, you need, probably take two of them, cut you're holes and weld them on. Again, you can use the strainer and stainless wire to hold them in place for screens.
There are lots and lots and LOTS of ideas and ways to do this. Do a search again, don't look for you're saw, look for ideas!!!
Me? I'm lazy, I drill holes, but it works!!!!:hmm3grin2orange:

Good info.
Yeah drilling works. just no creativity.

 

[sawinredneck]

Good info.
Yeah drilling works. just no creativity.

Wasn't arguing that point at all:hmm3grin2orange:

 

[manual]

Wasn't arguing that point at all:hmm3grin2orange:

Naw, me neather.

However I do like a muffler mod to where you can remove the screen.

 

[captain]

Alright,

Thanks for the insight

I will stick with the 85%. The stock deflecter is welded on the top of the muffler. I don't know what size stock hole it is covering.
Does anyone know what size it is?

also, This muffler has a full baffle in it with one hole in the lower corner of it (guesing about 3/4 inch) that leads to the front chamber where the exit "straw" goes up to the stock exit on top.

When I drill a new exhast hole should I drill through the baffle????

Thanks

 

[StihlBoy440]

Well with your description of you baffle yours is not an E-tech style, that is a good thing!

 

[Vance in AK]

Bringing an OLD thread back to life...
I recently picked up a mid 2011 manufacture CS2159 C that I want to muffler mod. I just picked up a nice used non cat (I believe, it's the same design as in the next to last post) Husky 359 muffler to mod. Anyone have pics, videos, or details that would help?

 

[RedFir Down]

I just Modded the muffler on my friends 359. I used a Husky 266 Deflector with the factory screen. On the clutch side cover of the muffler I cut out a rectangular hole the SAME size as the deflector on the cylinder side of the muffler seam. (that way you dont have to cut out any of the baffling out of the muffler). I had to bend and shape the deflector to conform to the shape of the muffler (really easy a pair of needle nose works good).
To fasten the new deflector on I drill 2 1/4" holes in the muffler so I am able to use 10X32 rivet nuts to fasten the screen and deflector. I like to screw the deflector on in order to have access to the screen (for those that like to run there saws rich) .
Make sure you deburr all of your cuts and holes and wash out all of your filings from the muffler.
I would post pics but he has the saw, sorry.

To take it a step farther I measured the cylinder squish and was able to remove the base gasket (that gave me a squish of .022). Which increased the compression by a strong 10psi.

Im telling you that REALLY woke that saw up! Every time my friend shuts his saw off he has a grin on his face!:msp_biggrin:

It also had a Walbro 199 problem carb on it so I sent to Tree Monkey for him to work his magic. (before he posted his 199 fix video) Im happy though, im glad he helped me and I helped him!!

Good luck and Enjoy

 

[4492011]

This is what I have done to my 359's but I now use rivet nuts instead of sheet metal screws. http://www.arboristsite.com/chainsaw/172643.htm

 

[Homelite410]

Here's a 359 I did, its a racer little bit extreme but I use it all the time in the timber. Idle is a little bit raspy but I don't mind. View attachment 310937

Here's my 2159 that I did.View attachment 310938

 

[RedFir Down]

This is what I have done to my 359's but I now use rivet nuts instead of sheet metal screws. http://www.arboristsite.com/chainsaw/172643.htm

Nicely done! That is really close to the way I did one for a friend of mine.