I can run that, I have a stock 241c here too. Believe I just swapped the stihl small spline onto it. Or ran the full 3/8 for a couple pulls. Don't remember which I did.
Chainsaw Dyno?
- Thread starter Red97
- Start date
I can run that, I have a stock 241c here too. Believe I just swapped the stihl small spline onto it. Or ran the full 3/8 for a couple pulls. Don't remember which I did.
Nutball
Active member
Can I have a copy of my 064 results in this format? I prefer it, more to look at.
Just a picture will do if you still have the data to generate it.
Just a picture will do if you still have the data to generate it.
Fabz
Active member
It’s got torque Roosevelt, fuzz quicker more than a Tennessee ported 395xp. If @Red97 has the Dyno results of a ported 395xp I’d be willing to wager the hp is about the same but the 064 is going to have more at a lower rpm. It will outcut with 20”,25”,28” and is dead even with a 32” ... we are only talking about a second here so ......
I'll try and print one tomorrow
That would be opposite of most 064/66 vs 395
The 395 puts out more down low torque the stihls better hp up top.
Fabz
Active member
Well , after running both of saws head to head many times using the Ghetto-tech “in the wood Dyno” the 064 out-pulls the 395xp down low and everywhere. You can actually hear the tone of the 064 cutting at a lower rpm , a Dyno simply won’t give you this musical experience 
... This is also with an 8pin on the 064 vs 7pin on the 395xp ......
... This is also with an 8pin on the 064 vs 7pin on the 395xp ......
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Fabz
Active member
I
I just looked up the factory specs for the 064 ... lists it at 6.5hp and 4.0ft/lbs torque stock. That saw according to the Dyno is 9+hp and only 4.3ft/lbs of torque. She’s gonna struggle to pull into the higher rpms where the power is. Curious @Red97 , how much of a correction factor is being used here? In other words STIHL says 6.5hp stock, I can see a guy getting maybe 8-8.5hp with a good woods port - maybe a bit more with a Hotwoods port but 9.76hp? I seriously doubt that saw would pull 6.5hp stock then 9.76hp on the STIHL Dyno unless it was piped .... which obviously it’s not. I’ve heard thru the grapevine that the 572xp (5.8hp factory rated) come in around 7hp on your unit so if it’s reading about 1-1.2hp higher than factory we should subtract that amount to compare apples to apples, trouble is , if ya do that then that 064 wood be making less torque than the stocker after being modded!
Nutball
Active member
As a personal rule of thumb, a 2 stroke should easily make .1HP per CC in the common 8-10krpm range if ported well, more is likely possible if ported very well, especially above 10,000rpm.
Testing in wood & the dyno would be a good way to confirm results, as I'm sure Joe has done before. That being said, I have run a stock 572 against a torquey Echo 590 I did, and I think they are pretty close to each other, roughly 5.8hp is very believable on both. The owner feels like the Echo is overall faster, but the 572 comes out ahead in big wood. He runs a 28" on the 590 and 36" on the 572.
I have had concerns that loading a saw too fast will artificially inflate the power output, but again, Joe should already know how fast it is safe to load them without loosing accuracy.
And don't forget, this is a later Tree Monkey saw, he's been at it a while, and should have the 064 recipe dialed in very well. You can tell in the video that it does very well for running a 9 tooth rim.
Testing in wood & the dyno would be a good way to confirm results, as I'm sure Joe has done before. That being said, I have run a stock 572 against a torquey Echo 590 I did, and I think they are pretty close to each other, roughly 5.8hp is very believable on both. The owner feels like the Echo is overall faster, but the 572 comes out ahead in big wood. He runs a 28" on the 590 and 36" on the 572.
I have had concerns that loading a saw too fast will artificially inflate the power output, but again, Joe should already know how fast it is safe to load them without loosing accuracy.
And don't forget, this is a later Tree Monkey saw, he's been at it a while, and should have the 064 recipe dialed in very well. You can tell in the video that it does very well for running a 9 tooth rim.
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I
I just looked up the factory specs for the 064 ... lists it at 6.5hp and 4.0ft/lbs torque stock. That saw according to the Dyno is 9+hp and only 4.3ft/lbs of torque. She’s gonna struggle to pull into the higher rpms where the power is. Curious @Red97 , how much of a correction factor is being used here? In other words STIHL says 6.5hp stock, I can see a guy getting maybe 8-8.5hp with a good woods port - maybe a bit more with a Hotwoods port but 9.76hp? I seriously doubt that saw would pull 6.5hp stock then 9.76hp on the STIHL Dyno unless it was piped .... which obviously it’s not. I’ve heard thru the grapevine that the 572xp (5.8hp factory rated) come in around 7hp on your unit so if it’s reading about 1-1.2hp higher than factory we should subtract that amount to compare apples to apples, trouble is , if ya do that then that 064 wood be making less torque than the stocker after being modded!
That 4.3 ftlb is made at 11,900
Max tq is made closer to 8500 and is just at 5 ftlb.
The stock 4ftlb is prolly made closer to 6000 rpm too. So in fact the ported saw makes more he all the way to 12,000 rpm than stock. Just pushed the peak tq rpm tight, thus pushing the max power higher.
Higher rpm tq is made the more horsepower an engine puts out. Also part of the reason this one wants to spin.
They are all apples to apples on my dyno. Everything gets a baseline run and after.
Anything that is mailed in for testing uses all the same correction factors as every other saw.
The factoy numbers don't mean much. Because I can't always duplicate factory numbers.
But sometimes they are very close..... like the 660 I have here have been within a few percent of factory numbers.
No need to subtract anything. Can only compare the numbers off of my dyno.
It would be unfair for me to use stock numbers.
Oh yeh this 572 makes 5.8 hp and after I port it makes 8hp on my dyno..... look at these huge gains..... nope not the case.
I get a shocking baseline of 7hp and 8hp after porting for real world gains that are shown.
Would only muddy the water trying to compare to stock factory numbers.
And no telling which numbers are posted. Factory Measured? 3rd party epa numbers? Theoretical calculated numbers?
I know the epa tested hp numbers is a bit different than the published numbers on some saws...
Any Echo horsepower numbers are from epa testing. Not echo themselves.
All of my runs are in the 8-11 second range. At my inertia will be the same from run to run..
I try and dial out 10 second runs, and I can match that pretty close if all the saws have the same powerband. But going from an 881 to a 2511 takes a couple practice pulls.
Well , after running both of saws head to head many times using the Ghetto-tech “in the wood Dyno” the 064 out-pulls the 395xp down low and everywhere. You can actually hear the tone of the 064 cutting at a lower rpm , a Dyno simply won’t give you this musical experience
Did you port both of those?
Very hard to make statements about the "type" of power a saw puts out if they were built by different people.
Some build for top end, some for low and others for the middle.
Just depends what was asked of the builder.
Fabz
Active member
I built the 064, that 395xp featured in that particular video was originally built by Terry Landrum from Tennessee in 2015- I also have 2 saws built by Hotsaws101- 241c insane-0 and a 461R extreme. Both builders are known for building strong saws. I don’t think Terry is STIHL running his operation anymore but Jack most certainly is. While not really a competition I figure if I can get close to, match or exceed known builders and the saws last then my builds are commercially viable. I build for torque , the rest takes care of itself ... I asked you what the correction factor was on your Dyno because most guys are getting about 20% gains. My 462c is 5.9hp stock and around 7.5hp modded. On your Dyno it would probably read 8.5hp+ .... I’ll take it 
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I built the 064, that 395xp featured in that particular video was originally built by Terry Landrum from Tennessee in 2015- I also have 2 saws built by Hotsaws101- 241c insane-0 and a 461R extreme. Both builders are known for building strong saws. I don’t think Terry is STIHL running his operation anymore but Jack most certainly is. While not really a competition I figure if I can get close to, match or exceed known builders and the saws last then my builds are commercially viable. I build for torque , the rest takes care of itself ... I asked you what the correction factor was on your Dyno because most guys are getting about 20% gains. My 462c is 5.9hp stock and around 7.5hp modded. On your Dyno it would probably read 8.5hp+ .... I’ll take it
I built the 064, that 395xp featured in that particular video was originally built by Terry Landrum from Tennessee in 2015- I also have 2 saws built by Hotsaws101- 241c insane-0 and a 461R extreme. Both builders are known for building strong saws. I don’t think Terry is STIHL running his operation anymore but Jack most certainly is. While not really a competition I figure if I can get close to, match or exceed known builders and the saws last then my builds are commercially viable. I build for torque , the rest takes care of itself ... I asked you what the correction factor was on your Dyno because most guys are getting about 20% gains. My 462c is 5.9hp stock and around 7.5hp modded. On your Dyno it would probably read 8.5hp+ .... I’ll take it
Correction factor on the dyno refers to weather corrections
I will have to check but all hp readings are calculated to the same "correction" which I believe is 70* temp and 50% humidity and 29.92" inch barometer.
Has the elevation figured in as well.
The weather station records all of that in real time during each run. Then "corrects" back to that standard used for all past and future tests.
So, I don't have a "correction" factor for saying I am 15% off stihls 23% off husky and 2% off echo published numbers.
What I do have is 1100+ dyno pulls on saws from all sorts of builder at all levels of the game. Along with stock "baseline" numbers to compare saws thst are sent in against.
I don't think it is possible to try to figure any correction factor from paper specs to my dyno specs.
No setup is perfect, I'm just getting rid of the chain and wood variables.
Fabz
Active member
So the echos are close , the STIHLS are off by 15% and the Husqvarner off 23%. Ok that makes sense now. So a Husqvarner 572xp wood be reading (5.8 x .23= 7.13hp) 7.13 hp stock and then with a decent woods port 7.13 (.20) approx 8.6hp or so if that’s what your getting... makes sense to me now. I was looking at it from the perspective of the 572xp saw putting out 5.8 stock and now ported its 8.6 and that’s approximately a 50% gain from published numbers... my mistake
That is what I am getting at, but the % I said were made up lol