haven't had it in the wood yet....we'll see. I've done my smaller saws with this method and have great results. There are pipes inside the muffler.
Muffler mod thread
- Thread starter Ronie
- Start date
tacotodd
Member
Have you ever heard of the spaghetti noodle trick? Take the dry noodles and fill the outlet on the cylinder or gasket or muffler inlet. Now for the math. Get between 60-75% of them and that will give you the idea for an outlet for whatever muffler you’ll be using. Multiple outlets are a leeetle harder to calculate.
Just sayin.
And I know I’m not Red
No, I've never heard that. From my own experiences, I've never had an outlet that was to big and I've put some big outlets on some small saws.
tacotodd
Member
tacotodd
Member
And remember, HP is a calculated measurement in relation to the MEASURED torque & RPM. I forget EXACTLY how to calculate it, but it’s amazing that we can get the ponies from a saw (and torque) that we do.
That's why I would like to hear Red97's thoughts on it, he's done a lot of dyno runs with different exhaust.
tacotodd
Member
10-4. Just throwing out what I DO know.
854tga+
New member
I was advised to watch out if your cutting really dry wood, potential for fire. I just love the sound of our XP390 piped muffler. Sounds like a 2 stroke dirt pipe. Haha
tacotodd
Member
All 2strokes should sound like that, or there’s something not quite right with them (box store variety for example)
That's why I try and put them coming out to one side or the other if I can. I think only one of my saws has the exit out the front, my Redmax g450.
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Fabz
Active member
I’m going to respectfully disagree. The chainsaw engine is far from a high performance engine, more like an outboard in that it gives good power and gets the job done but also lasts for 1000-2000hrs. Of course we can “enhance” the output by certain modifications , sometimes at the expense of longevity but the inherent design limits the amount of torque/hp that can be produced. You’ll never get a 70cc chainsaw to produce the HP a 70cc dirt bike will. Be lucky to get 1/2 lol
Some like big, some double medium. And some like even bigger.
Depends on the port arrangement and carb/filter. Lots of things at play for a given saw.
85% of the time 1/2-3/4" hole works well.
For my 372xt, I measured out the exhaust port size & opened up holes in the muffler (2) about the same size…as I run screens 100% of the time, I figured in the approximate obstruction from them and ended up @ ~ 70% of the intake opening for the exhaust outlets…seems to work well
Chris Paul
Member
Fabz
Active member
While there is more than just a simple muffler mod on this saw, it gives an example of everything working in concert (tuned intake , flow porting and tuned dual tube exhaust). There is No , I repeat NO machining work on this saw , timing is factory and the squish is stock (no base gasket delete). Iirc the squish was .030 from the factory ...
tacotodd
Member
It looks like you’re cutting in socks. Or did I see something else?
I will admit, on first view I thought the same, but I think it might be tennis shoes under the bottom cuffs of a pair of chainsaw chaps?
Or maybe he borrowed Grandma's slippers?
