You need to put one like this on the dyno
First tank of fuel too.
First tank of fuel too.
I call B.S. on Stihl. My dyno doesn't lie. MS 461 is king over MS 660
- Thread starter chadihman
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Is that a genuine Bjorn Borg commemorative sweat band?
That's an "I sweat like a pig" king of sweat band
chadihman
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Got another test of the Stock 461 vs stock 660 and i'm calling the 660 broken in. 461 still looks better most of the rpms
chadihman
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This makes a difference. Here's the stock 461 vs the 660 with a dual port muffler. Dp makes the 660 king again.
chadihman
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Here's the 660 vs 660 DP. Some really nice gains with a dual port. This DP was a complete Hyway dual port muffler with the screens removed from both ports and the stupid baffle thing removed from the inside.
Looks like the DP smoothed the curve in addition to the bump in power.
Ron660
Addicted to ArboristSite
This makes a difference. Here's the stock 461 vs the 660 with a dual port muffler. Dp makes the 660 king again.
I'd like to see the results if both saws were ported.
Terry Syd
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Great thing about the dyno is it lets you see what is happening along the curve. Take a look at the dip in power of the 461 at 8,000 rpm. What's causing that? With the dyno, someone could try a few things and find out why that dip is occurring - and fix it.
Cutting cookies off a log isn't going to give you the same insight that the dyno will.
Cutting cookies off a log isn't going to give you the same insight that the dyno will.
WOW, almost 1.2 HP at 10,000 RPM, that is a lot! Any idea how much difference removing the baffle made?
I was not going to remove that on the 046, but now ..... I don't know.
Do replacement 044/440 mufflers have the baffle? If they don't I could just get one of them and put the dual port cover on it.
I was not going to remove that on the 046, but now ..... I don't know.
Do replacement 044/440 mufflers have the baffle? If they don't I could just get one of them and put the dual port cover on it.
Terry Syd
Addicted to ArboristSite
In regards to the dip in power at 8,000 on the 461, here's the first test I would do to see if it was a carburetion problem.
In the past I have found that the low speed circuits have been set lean to get around EPA limits. I don't know when the situation started, probably some of the old hands will remember when the 'emission' carbs came in. The difference in carbs is quite significant, the low speed circuits were set lean and the high speed circuit was required to do most of the fuel flow in the carb.
That 'dip' could well be a result of the low speed circuit fuel flow flattening out and then the high speed circuit coming in and bringing the power back up.
So you get the 461 on the dyno, get the rpm at 8,000 and then start increasing the fuel flow on the high speed circuit. If the power comes up at 8,000, then you got a fuel flow problem - and the problem is probably a lean low speed circuit.
Of course, increasing the high speed circuit will kill the power up higher in the powerband, but you don't care, you are trying to find out why the dip is happening. Now you know and you can start modding the carb to get more flow in the low speed circuit to bring the two fuel curves together at 8,000.
In the past I have found that the low speed circuits have been set lean to get around EPA limits. I don't know when the situation started, probably some of the old hands will remember when the 'emission' carbs came in. The difference in carbs is quite significant, the low speed circuits were set lean and the high speed circuit was required to do most of the fuel flow in the carb.
That 'dip' could well be a result of the low speed circuit fuel flow flattening out and then the high speed circuit coming in and bringing the power back up.
So you get the 461 on the dyno, get the rpm at 8,000 and then start increasing the fuel flow on the high speed circuit. If the power comes up at 8,000, then you got a fuel flow problem - and the problem is probably a lean low speed circuit.
Of course, increasing the high speed circuit will kill the power up higher in the powerband, but you don't care, you are trying to find out why the dip is happening. Now you know and you can start modding the carb to get more flow in the low speed circuit to bring the two fuel curves together at 8,000.
I can tell you how to get rid of that dip. PORT IT!!!
KG441c
Keith
I like that idea better!! lolI can tell you how to get rid of that dip. PORT IT!!!
CapitaineHaddoc
European Westcoaster
Thank's for your work, Chad, your graph is awesome. I think i'll gring the baffle inside my 064's dual port muffler!
What about the torque with the DP muffler? I feel that my 562 gains a lot of torque with a muffler mod...
What about the torque with the DP muffler? I feel that my 562 gains a lot of torque with a muffler mod...
weedkilla
Ain't no guru of nuthin'
What is commonly described as "torque" is power lower in the rev range, or how low in the rev range a saw can go before the power drops off.
It's shown in these power graphs as well as if he had graphed raw torque figures.
See how the 660 dp is still making as much power at 7000rpm as the standard one does at max? That's what you feel as "torquey".
Although, looking at the graph for the 660 I think you'd just feel like it gained everywhere. Because it would achieve higher revs in the cut, as well as hold on lower without bogging it would feel like a much bigger gain than the 10% increase in max power.
Sorry for the "" rubbish, it's just that I don't want to confuse the way these terms are used with their correct meaning, even when that only varies slightly.
It's shown in these power graphs as well as if he had graphed raw torque figures.
See how the 660 dp is still making as much power at 7000rpm as the standard one does at max? That's what you feel as "torquey".
Although, looking at the graph for the 660 I think you'd just feel like it gained everywhere. Because it would achieve higher revs in the cut, as well as hold on lower without bogging it would feel like a much bigger gain than the 10% increase in max power.
Sorry for the "" rubbish, it's just that I don't want to confuse the way these terms are used with their correct meaning, even when that only varies slightly.
MCW
Somebody's talking crap here & it ain't the tree!
Awesome graphs. Goes to show why guys in Australia have been somewhat disappointed with their MS461's against their dual port MS660's.
The single port cover really does choke it up - more than I thought it would actually.
The single port cover really does choke it up - more than I thought it would actually.
Here's the 660 vs 660 DP. Some really nice gains with a dual port. This DP was a complete Hyway dual port muffler with the screens removed from both ports and the stupid baffle thing removed from the inside.
23% more power at 10,000 rpm. Not too shabby for a bolt on.
I wonder if muffler mods will have a similar effect on the 461. Something tells me we are going to find out.
I also wonder how much difference removing the baffle makes.
The muffler mod made as much difference as going to a larger saw!
I also wonder how much difference removing the baffle makes.
The muffler mod made as much difference as going to a larger saw!
I am surprised that peak HP for both 660s remained at 9,000, I would have thought the dual port would have moved it higher.
That said, it is very impressive that the dual port has more power than the "Stock peak HP" from 7,000 - 10,500 RPM.
That said, it is very impressive that the dual port has more power than the "Stock peak HP" from 7,000 - 10,500 RPM.
