My internal frequency monitoring device told meThen how do you know you found more rpm?
MS661C Muffler Mod Testing
- Thread starter blsnelling
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SquareFile
ArboristSite Guru
Chris-PA
Where the Wild Things Are
It looks like you did 4 cuts each video, pushing harder each time? For consistency which cut do you want the rpm on?
Highest and lowest RPMs.
Chris-PA
Where the Wild Things Are
OK, here's what I did: I watched each video to try to find cuts that sounded consistent and steady. Then I picked a light and a high load section from each video to plot. I noticed when listening that the high load cuts varied a lot more, and this showed in the plots where the width of the spike was much wider than for the light load. And I had to pick a section carefully to get a clean a plot as I did. But then this is not a surprise with a powerful saw pushed through...what the hell was that anyway?
I had to put the cursor somewhere on the high load plots so I mostly picked the middle. Given that, the results were remarkably consistent. Here are the plots (you can see the name at the top) - the area that is shaded on the time plot is the area that is plotted in the frequency analysis, with the heavier loading being later in time:
Here are the numbers I came up with (wish this thing did tables, and it removes extra spaces):
Config--- Load--Freq---RPM
BISI-------Light---167----10020
BISI-------High---141-----8460
BOSI------Light---172----10320
BOSI------High---141-----8460
BOSO-----Light---166-----9960
BOSO-----High---140----8400
BOSODP--Light---167----10020
BOSODP--High---144-----8640
Of course this is just rpm, and you have to combine it with times to have it mean much.
I had to put the cursor somewhere on the high load plots so I mostly picked the middle. Given that, the results were remarkably consistent. Here are the plots (you can see the name at the top) - the area that is shaded on the time plot is the area that is plotted in the frequency analysis, with the heavier loading being later in time:
Here are the numbers I came up with (wish this thing did tables, and it removes extra spaces
):Config--- Load--Freq---RPM
BISI-------Light---167----10020
BISI-------High---141-----8460
BOSI------Light---172----10320
BOSI------High---141-----8460
BOSO-----Light---166-----9960
BOSO-----High---140----8400
BOSODP--Light---167----10020
BOSODP--High---144-----8640
Of course this is just rpm, and you have to combine it with times to have it mean much.
Thanks Chris. Very cool. Thanks for the effort.
I forgot I hadn't uploaded this one. What's it making at 0:16, and 0:39?
Actually, a lot of big saws don't show their power unless they are running longer bars. In 20" wood, I'll put my stock 044 up against a stock 660 any time, although the 660 would win in bigger wood.
The 661 and ported big saws are different, they generally cut very fast with smaller bars.
Deets066
Firewood hack
Moparmyway
Its just a saw
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Chris-PA
Where the Wild Things Are
Well, it's screaming at 16s - 12,000rpm:
Around 39s it's varying a bit, from 7,440 to 11,100rpm. The center is around 9,000rpm:
7,400-12,000. I'll take that!
Bingo...you beat me to it..thanks dawg
Mike , if you gear a 90cc saw properly its gonna pound a 70 cc saw in 20" wood.
And i hope a 660 beats a 044 in bigger wood...its 20cc bigger..it better beat it...i know what all these saws do mike , you really dont have to point out the obvious to me..but thank you for the contribution.
The fastest combination is no baffle and as much exit area as your ears can tolerate.
Brad, is that on ported saws, or all saws? I think in some of his previous tests, the baffle helped the stock saw, but not the ported one.
I don't test stock saws to that level, but would be very surprised to see it any different.
Trx250r180
Saw polisher
My ms460 seemed to like the baffle when it was stock vs gutted ,stock baffle ,rh opening enlarged ,and dual cover it was happy on my particular saw ,once ported ran better gutted .
Go big or go home!![emoji6]
Squad_Boss
ArboristSite Lurker
What purpose does a 20 inch bar serve on a 90cc class saw? Just curious.
I recently picked up a 661 and it doesn't cut any faster than my 362 until it's buried in bigger wood.
661 36 inch bar
362 28 inch bar
I recently picked up a 661 and it doesn't cut any faster than my 362 until it's buried in bigger wood.
661 36 inch bar
362 28 inch bar
