No matter what the HP numbers say, no way will the 3.8 hp MS290 cut any where near as fast as the simular or less HP MS261, 346xp or a Dolmar 5105 or any of my Echo Cs510-520 saws. Number are just that. Steve
Dyno #'s for Husq Stihl Dolmar Solo
- Thread starter one.man.band
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one.man.band
ArboristSite Guru
realize that peak power and torque figures do not tell the whole story, a graph would tell the tale. no way to compare the areas under the curve on those 50cc saws. asked about the performance of the saws listed to get some kind of idea if any conclusions could be made.
i know what kind of curves work for heavy v twins. a dynojet dyno vs. a superflow are different. superflow will read less every time. shops fudge barometric pressure, tire air pressure, seated or unseated during runs. bikes can easily be made "dyno queens." spinning a drum around can give an good indication of what to expect when putting on a helmet. bikes that perform well on a dyno will still require tuning after test riding. the difference between dyno tuned and test rode is adjusting a more few more degrees advance timing. the drum does not simulate a load a 200 pound rider well. a cool feature of the dynojet would let you simulate a drag race between any saved runs from different bikes.
as Stumpy says ......(dyno) as a tuning tool....they would work very well. if i had a saw that was actually worth a mod, i would send it to him in a heartbeat!!!
the peak RPM power and torque figures looked very close for the 346XP, and Dolmar PS 4605. the Dolmar 5105 was similar but with more power and torque. the Stihl 260 had #'s the same as the 5105, but at lower RPM. there must be some kind of difference between how these saws cut wood. i don't own or have i used any of them.
i know what kind of curves work for heavy v twins. a dynojet dyno vs. a superflow are different. superflow will read less every time. shops fudge barometric pressure, tire air pressure, seated or unseated during runs. bikes can easily be made "dyno queens." spinning a drum around can give an good indication of what to expect when putting on a helmet. bikes that perform well on a dyno will still require tuning after test riding. the difference between dyno tuned and test rode is adjusting a more few more degrees advance timing. the drum does not simulate a load a 200 pound rider well. a cool feature of the dynojet would let you simulate a drag race between any saved runs from different bikes.
as Stumpy says ......(dyno) as a tuning tool....they would work very well. if i had a saw that was actually worth a mod, i would send it to him in a heartbeat!!!
the peak RPM power and torque figures looked very close for the 346XP, and Dolmar PS 4605. the Dolmar 5105 was similar but with more power and torque. the Stihl 260 had #'s the same as the 5105, but at lower RPM. there must be some kind of difference between how these saws cut wood. i don't own or have i used any of them.
Stumpys Customs
Stumpbroke
FATGUY
Addicted to ArboristSite
area under the curve boys, albeit less important than in automotive racing and certainly over a more narrow band.
-oops, somebody aleady brought this up, sorry.
-oops, somebody aleady brought this up, sorry.
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The facts are what they are and can't be disputed, to a point. I'm sure every saw in the test was ran with factory carb settings. This gives us a good indication of how a saw will run out of the box, but necessarily the saws true potential. I also doubt any of the saws in the test were broken in. Nevertheless I go by what my hands and cut times tell me, not just buy a number on paper.
tuning by dyno
A dyno is a tool;I can't tell you how many time I have heard you can't race a dyno.I believe you cant race without a dyno.All also would hear same thing about a flow bench.All I am saying is dyno testing before and after porting will give you better insight on how you are affecting the tork & hp curve on your saw.The more knowledge gained the better.Steve
A dyno is a tool;I can't tell you how many time I have heard you can't race a dyno.I believe you cant race without a dyno.All also would hear same thing about a flow bench.All I am saying is dyno testing before and after porting will give you better insight on how you are affecting the tork & hp curve on your saw.The more knowledge gained the better.Steve
one.man.band
ArboristSite Guru
my friend who has cut wood for a living for the last 27 years gives me a puzzled look when i talk to him about getting gains in power. he says "i just grab a bigger saw." he's a big guy, so his small saw is a 44.
some folks just don't feel the need for more.
for the 50cc saws i keep talking about: the one with the most power, has a 0.54 HP advantage over the one with the least. that's 13.9% better. the one with the most torque, has a 0.37 ft/lb. advantage over the one with the least. that's 15.7% better. is that enough to switch to the next bigger bar and bury it?..... i don't know.
just a lot left on the table, even with smog regs being the same for each manufacturer. the dyno tests were from germany, maybe things there are different.
dealer support while its under warranty and parts availability are my picking points, but i do seem to like the bonus sway that power has.
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50cc saw graphs. before anyone says that you can't do this for peak power and torque, take a look. each saws peak power and torque were graphed using two data RPM's given in the dyno test. real dyno graphs use many more points and are typically not just a straight line.
the first page lists the data. metric power (k Watts and Nm), and to the right english units (HP and Ft./lbs). i converted the english from the metric data by formulas.
the page 2 graph shows saws and peaks for metric lovers. the crossover point is different using metric.
the page 3 graph shows english data. the heavy (bold) lines are from the actual dyno data. the thin blue lines, are a projection which i drew in. (i did not have the time or patience to calculate these slopes, so a just extended them). the 3rd point is "plotted" to the point where all english HP and TQ curves intersect at approximately 5250 give or take a few RPM with my line extension ability).
all in all the saws are generally similar.
see attachment.
some folks just don't feel the need for more.
for the 50cc saws i keep talking about: the one with the most power, has a 0.54 HP advantage over the one with the least. that's 13.9% better. the one with the most torque, has a 0.37 ft/lb. advantage over the one with the least. that's 15.7% better. is that enough to switch to the next bigger bar and bury it?..... i don't know.
just a lot left on the table, even with smog regs being the same for each manufacturer. the dyno tests were from germany, maybe things there are different.
dealer support while its under warranty and parts availability are my picking points, but i do seem to like the bonus sway that power has.
-----------------------------------------------------------------------
50cc saw graphs. before anyone says that you can't do this for peak power and torque, take a look. each saws peak power and torque were graphed using two data RPM's given in the dyno test. real dyno graphs use many more points and are typically not just a straight line.
the first page lists the data. metric power (k Watts and Nm), and to the right english units (HP and Ft./lbs). i converted the english from the metric data by formulas.
the page 2 graph shows saws and peaks for metric lovers. the crossover point is different using metric.
the page 3 graph shows english data. the heavy (bold) lines are from the actual dyno data. the thin blue lines, are a projection which i drew in. (i did not have the time or patience to calculate these slopes, so a just extended them). the 3rd point is "plotted" to the point where all english HP and TQ curves intersect at approximately 5250 give or take a few RPM with my line extension ability).
all in all the saws are generally similar.
see attachment.
one.man.band
ArboristSite Guru
Thanks for the comment.
Any saw is worth modifying.
stumpy....since i have been on this site, i read the helpful advice you have given to others. sure don't mind giving a plug for a stand-up guy.
OMB
Stumpys Customs
Stumpbroke
My thought's exactly.
Thanks agian, I do what I can to help.:msp_biggrin:
husq2100
Addicted to ArboristSite
chain speed!.............that is all
one.man.band
ArboristSite Guru
agree....and that is all done in the wood with torque over time ... HP.
ECHO-Echo-echo
ArboristSite Operative
Selecting a saw is like picking a spouce. We all look at the numbers (36-28-36) when trying to decide on a new saw(hp, weight,b/c,rpm). After selecting several in the same ball park then it comes down to dealer service(inlaws), does some one you know have one (sister), are you a contrarien, go against the flow. It comes down to a pretty face....when you sit at the dining room table every day you have to look at her....All the other numbers you can live with. I want robust, dependable, easy start, a women/saw that will last a lifetime....and beautiful.
I ordered my new dolmar 420 because she is beautiful to me. I love the color, a redish orange and black. I can make it work for me, what ever the numbers.......But i'm a casual user, 1 or 2 cords a year.
But it is nice to see the numbers.
I ordered my new dolmar 420 because she is beautiful to me. I love the color, a redish orange and black. I can make it work for me, what ever the numbers.......But i'm a casual user, 1 or 2 cords a year.
But it is nice to see the numbers.
