actual HP gains with a muffler mod

[o8f150]

A 372 muffler has nothing more than a small slit for exhaust area, a long ways from very open and non-restrictive.

i run my 372,,not in wood,, before i did the MM on it, the throttle responce was good but not fantastic,, i did the MM on it with an additional 3/4" pipe and it really improved the responce,,, to me it made a big difference,, like some said about the echos it wakes them up because of the cats in them,,, i know it really woke my 361 up when i opened it up

 

[rutterb]

my echo cs 400 has really impressed me with a muffler mod. mind you I had to gut the cat that it came with and richen it up a bit but the difference in the performance night and day. I own three stihl chainsaws and I am a stihl guy and I know that most on this site bash echo saws but this 40cc saw kicks butt. I went from the 18in bar to a 16in oregon pro lite with a 3/8 lp chain and this saw will cut without bogging down using full bar length in white oak the saw has really good torque. When I first bought this saw I was very disapointed with it's performance but with the mods it's a runner .Of all the saws that are sold Echo is the only manufacturer that does not post HP ratings but regardless this is one good little saw.

 

[Axlerod74]

My post was less than serious, and I meant no mockery to the performance of muffler mods. I noticed quite the difference on my saw when I completed the mod - more than just sound :msp_wink:

Not only does opening up the outlet help, but an additional outlet in a more strategic position to benefit flow should also produce gains. I couldn't tell you how much truth there is to that, but it sounds good in my head.

I can see the logic in placing a bigger opening in a more strategic place. I did not mean to imply that you were only intrested in sound. This is just a topic of intrest to me as I have considered a mm but was unsure how much benefit it would make in end performance. Thanks for the insight, makes sense.

 

[Axlerod74]

A 372 muffler has nothing more than a small slit for exhaust area, a long ways from very open and non-restrictive.

By open and non-restrictive, I ment in comparison to cat mufflers and most other saws I see with baffles and cross tubes. Compared to 85% if the mufflers I have looked at..........this one is pretty open inside but you are right, the narrow, outside opening is right in line with most other stock saws.

I would consider a mm for my 372. What do you recommend, from your experience, to get the most out of the saw as striclty a firewood and tree service saw. Nothing competative, just improved performance without compromising engine life.

 

[Ambull]

By open and non-restrictive, I ment in comparison to cat mufflers and most other saws I see with baffles and cross tubes. Compared to 85% if the mufflers I have looked at..........this one is pretty open inside but you are right, the narrow, outside opening is right in line with most other stock saws.

I would consider a mm for my 372. What do you recommend, from your experience, to get the most out of the saw as striclty a firewood and tree service saw. Nothing competative, just improved performance without compromising engine life.

I think Baileys has a pretty nice aftermarket muffler for the 372. I have been to two GTG's where Baileys donated a bunch of those things to the raffle. Seem to be pretty well put together. Since Baileys was kind enough to make the donation, they deserve the plug!!!!

 

[Ambull]

20% on the 395 would be about 1.5hp Which is a fantastic gain

Yeah I am probably exaggerating, but it is a big difference. the 90cc plus saws move a lot of air, and will benefit greatly when the exhaust is opened up. I noticed a big difference in my Jonsered 2094 too.

 

[o8f150]

By open and non-restrictive, I ment in comparison to cat mufflers and most other saws I see with baffles and cross tubes. Compared to 85% if the mufflers I have looked at..........this one is pretty open inside but you are right, the narrow, outside opening is right in line with most other stock saws.

I would consider a mm for my 372. What do you recommend, from your experience, to get the most out of the saw as striclty a firewood and tree service saw. Nothing competative, just improved performance without compromising engine life.

i welded a 3/4" id tube to the top right corner of my 372,, it really made the throttle responce better

 

[himiler]

Madsens advertises some pretty sophisticated devices to measure the output of saws they work on, but as far as I know they don't publish any data on any mods be they mufflers or porting, etc. .
My guess is if that info were published for the sake of selling mods or muffs, the EPA would promptly shut em down! Not to mention Stihl, Husky, et al would probably have a fit. So, either someone has access to a dyno of some sort to test their personal saws or it's seat of the pants cookie cutter comparisons.
Steve W.

 

[MacLaren]

I have heard that putting a Dual Port Muffler cover on a Stihl MS660 will increase h.p. by 8/10th. =7.0 to 7.8.
I also understood it was dyno'd and proven. That may be total b.s. I could really care less, but thats what I have heard.

 

[sh33pl3dog]

Hello all, not sure if anyone is still wondering about this but if on a Stihl ms660 on Dyno stock hp. 7.01 torque 4.92
a 3/4" pipe mod with a 45 degree angle produced 7.75 HP and 5.25 torque
A 1" pipe mod curving down like an elephant trunk put out 8.02HP and 5.33 torque
I'm sure the results would differ on an 024 but those kinda gains are enough to make me mod my 024 super right now lol.