Hi folks, it's been a while since I last posted any technical content, so here's an update. I was contacted by Matt of Gearhead Performance about testing some new custom machined outlet deflectors for Echo Chainsaws. Here's his contact info:
Gearhead Automotive Performance
979-703-7338
https://www.ghtuning.com/product/cnc-machined-and-upgraded-chainsaw-parts/
Testing was performed on my SuperFlow SF-110 Flow bench. It's been upgraded a bit since I last posted CS-590 muffler Flow numbers in 2016.
Here's the really nicely designed exhaust outlet deflector that Matt has created. It has been designed to maximize the exhaust flow/volume yet still fit under the stock plastic and exit in the stock direction. It is CNC machined from 6061 alloy and it is a bolt on direct replacement for the OEM sheet metal deflector.
Matt did a nice job with the engineering on this part. He's even done some Computational Fluid Dyanmics (CFD) modeling and we are continue to collaborate on the 590 muffler as I believe there is a way to re-engineer the stock muffler in such a way to really uncork some more performance on this saw.
I flow tested the stock muffler he sent me, to obtain a baseline. I then tested a "modified stock" deflector, modified in the common way, and as I spelled out in my original thread flowbench testing these mufflers:
https://www.arboristsite.com/thread...f-muffler-mod-flow-bench-measurements.299923/
The test sequence for this round of testing is as follows:
1. stock
2. modified stock deflector with screen
3. billet deflector with screen
4. billet deflector no screen
5. no deflector, no screen (not possible to operate this way on the saw....would exhaust directly into the plastic)
6. billet deflector with screen and (6) .125 holes drilled
7. billet deflector no screen and (6) .125 holes drilled
8. billet deflector with screen and (4) .1875 holes and (2) .125 holes
Relative to the rest of the engine (the carb), The muffler is airflow limited in stock form. Drilling the extra holes significantly changes the airflow, both by redirecting air bypassing the internal baffle, and by increasing the total exit flow area. Of the 6 holes drilled, the four that are closest to the exhaust port are in the first chamber of this muffler.
Pictures of each test setup:
1. Stock
2. modified stock deflector (shown with no screen installed)
3. Billet deflector (looks bad-ass!):
4. (6) .125 holes and their locations (they have been deburred but the photos magnifies some paper towel residue on them):
5. And the Final hole configuration, (4) .1875 and (2) .125:
The purpose of the testing was to
a) re-validate my 2016 flow results
b) determine the benefit of the new deflector on a stock (non drilled) muffler and
c) determine how much additional flow gains can be achieved when using this new deflector with a drilled muffler.
Since this post is getting a bit long, I will put the results in a separate post.
Gearhead Automotive Performance
979-703-7338
https://www.ghtuning.com/product/cnc-machined-and-upgraded-chainsaw-parts/
Testing was performed on my SuperFlow SF-110 Flow bench. It's been upgraded a bit since I last posted CS-590 muffler Flow numbers in 2016.
Here's the really nicely designed exhaust outlet deflector that Matt has created. It has been designed to maximize the exhaust flow/volume yet still fit under the stock plastic and exit in the stock direction. It is CNC machined from 6061 alloy and it is a bolt on direct replacement for the OEM sheet metal deflector.
Matt did a nice job with the engineering on this part. He's even done some Computational Fluid Dyanmics (CFD) modeling and we are continue to collaborate on the 590 muffler as I believe there is a way to re-engineer the stock muffler in such a way to really uncork some more performance on this saw.
I flow tested the stock muffler he sent me, to obtain a baseline. I then tested a "modified stock" deflector, modified in the common way, and as I spelled out in my original thread flowbench testing these mufflers:
https://www.arboristsite.com/thread...f-muffler-mod-flow-bench-measurements.299923/
The test sequence for this round of testing is as follows:
1. stock
2. modified stock deflector with screen
3. billet deflector with screen
4. billet deflector no screen
5. no deflector, no screen (not possible to operate this way on the saw....would exhaust directly into the plastic)
6. billet deflector with screen and (6) .125 holes drilled
7. billet deflector no screen and (6) .125 holes drilled
8. billet deflector with screen and (4) .1875 holes and (2) .125 holes
Relative to the rest of the engine (the carb), The muffler is airflow limited in stock form. Drilling the extra holes significantly changes the airflow, both by redirecting air bypassing the internal baffle, and by increasing the total exit flow area. Of the 6 holes drilled, the four that are closest to the exhaust port are in the first chamber of this muffler.
Pictures of each test setup:
1. Stock
2. modified stock deflector (shown with no screen installed)
3. Billet deflector (looks bad-ass!):
4. (6) .125 holes and their locations (they have been deburred but the photos magnifies some paper towel residue on them):
5. And the Final hole configuration, (4) .1875 and (2) .125:
The purpose of the testing was to
a) re-validate my 2016 flow results
b) determine the benefit of the new deflector on a stock (non drilled) muffler and
c) determine how much additional flow gains can be achieved when using this new deflector with a drilled muffler.
Since this post is getting a bit long, I will put the results in a separate post.
