Another chainsaw dyno...

[huskihl]

What’s holding back the echo from making as much power as a 372 or hybrid? Great gain on the saw... just curious.

I’m not sure. I tried several different ways and in the end I decided that it looked sort of similar to a 372 inside and ported it like a 372. It was actually only one second behind a ported 500 and ported 385 with the same 28” bar and chain a couple days later.

 

[Bigmac]

What’s holding back the echo from making as much power as a 372 or hybrid? Great gain on the saw... just curious.

How much more are 372’s making?

 

[huskihl]

I’m not sure. I tried several different ways and in the end I decided that it looked sort of similar to a 372 inside and ported it like a 372. It was actually only one second behind a ported 500 and ported 385 with the same 28” bar and chain a couple days later.

I guess what I mean in that last statement is that there there’s more to how a saw cuts than what we are perceiving as good in the dyno sheets. I hung out with Joe yesterday for a few hours and he is starting to pick up some things on what he feels in a saw when you compare the horsepower line to the torque line.

 

[cuinrearview]

I guess what I mean in that last statement is that there there’s more to how a saw cuts than what we are perceiving as good in the dyno sheets. I hung out with Joe yesterday for a few hours and he is starting to pick up some things on what he feels in a saw when you compare the horsepower line to the torque line.

Does this mean you guys are collaborating on a half rotten elm port n' tune?

 

[jacob j.]

Does this mean you guys are collaborating on a half rotten elm port n' tune?

I think Joe only cuts straw bales and the occasional roadkill wild hog
(>600 pounds).

 

[huskihl]

Does this mean you guys are collaborating on a half rotten elm port n' tune?

Silver maple, but yes

 

[RI Chevy]

I guess what I mean in that last statement is that there there’s more to how a saw cuts than what we are perceiving as good in the dyno sheets. I hung out with Joe yesterday for a few hours and he is starting to pick up some things on what he feels in a saw when you compare the horsepower line to the torque line.

And I got my balls busted when I said go from Dyno right to wood to confirm the results with a given saw.
A saw that performs great on a Dyno may not perform great in wood. And vice versa.
There may be saws that perform great in both.
In the end, the only thing that matters is how the saw performs while doing the task that it was made for. Cutting wood.
Saws perform differently in hard wood and soft wood. Saws perform differently with long bars and short bars.
It would just be nice to get confirmation from both a Dyno AND real world testing.

 

[cuinrearview]

And I got my balls busted when I said go from Dyno right to wood to confirm the results with a given saw.
A saw that performs great on a Dyno may not perform great in wood. And vice versa.
There may be saws that perform great in both.
In the end, the only thing that matters is how the saw performs while doing the task that it was made for. Cutting wood.
Saws perform differently in hard wood and soft wood. Saws perform differently with long bars and short bars.
It would just be nice to get confirmation from both a Dyno AND real world testing.

But...this..is the....dyno thread.

 

[Red97]

And I got my balls busted when I said go from Dyno right to wood to confirm the results with a given saw.
A saw that performs great on a Dyno may not perform great in wood. And vice versa.
There may be saws that perform great in both.
In the end, the only thing that matters is how the saw performs while doing the task that it was made for. Cutting wood.
Saws perform differently in hard wood and soft wood. Saws perform differently with long bars and short bars.
It would just be nice to get confirmation from both a Dyno AND real world testing.

The conversation was more along the lines of what people "feel" while running a saw. Vs what the dyno shows.

Most of the old comments were always ported saws "lose low end tq"

Out of all the saws I've seen only 1 or 2 have had less tq than stock once ported.

It is in the shape of the curves, and the power delivery that makes saws feel a certain way.

Along with cutting style, and chain style.

Some need to be dogged in and pulled down to 8k rpm to cut best, others need 11k.

But I am starting to see a trend in these graphs that seems to correlate with what people say they are feeling in certain saws.

So far most every saw with more power has cut faster than the ones with less. As seen by the stock videos vs the dyno runs of the stock saws. Along with the hand full of ported saws that have been run before/after on the dyno and in the wood

Kevin had close to 38% gains in the wood, and it is around 40% on the dyno. With that 7310

 

[RI Chevy]

But...this..is the....dyno thread.

Aye!!! You can lead the horse to water, just can't make him drink...‍

 

[RI Chevy]

@Red97

If a porter ported a saw and it produced less torque than stock, then something is wrong...
Time to find a new porter...lol

 

[cuinrearview]

Aye!!! You can lead the horse to water, just can't make him drink...‍

Can't lead him away from the dyno thread to the chain thread or the video thread or the wood species discussion thread either.

 

[Red97]

@Red97

If a porter ported a saw and it produced less torque than stock, then something is wrong...
Time to find a new porter...lol

That was always the saying I heard when I was getting into saws.

If you port them, they can/will lose some low end tq. Etc.

 

[cuinrearview]

That was always the saying I heard when I was getting into saws.

If you port them, they can/will lose some low end tq. Etc.

I know how to make them lose low end ass. I've done it.

 

[huskihl]

And I got my balls busted when I said go from Dyno right to wood to confirm the results with a given saw.
A saw that performs great on a Dyno may not perform great in wood. And vice versa.
There may be saws that perform great in both.
In the end, the only thing that matters is how the saw performs while doing the task that it was made for. Cutting wood.
Saws perform differently in hard wood and soft wood. Saws perform differently with long bars and short bars.
It would just be nice to get confirmation from both a Dyno AND real world testing.

You got your balls busted because sometimes you say dumb *s-word and people like giving you a hard time for it.


It doesn’t really matter how they perform in wood compared to the dyno. This dyno exists so you can see the numbers that your saw produces. I’ve never looked at it as a competition of any sort, it’s to satisfy my curiosity about what I felt in a log vs what the contraption says. What good are bragging rights when somewhere out there there are thousands of other saws that are faster or perform better on the dyno? That’s just setting yourself up for certain eventual failure. All we are is ants on a hill in the world of performance chainsaws.


When I want confirmation of how a particular saw runs in a log, I have Joe run it on the dyno. Some of my customers have asked for “spicy” 7900’s and some have asked for a more forgiving saw that they can lean on more. Spicy curves are narrow and high. Forgiving curves are lower and flat. Both are acceptable for a worksaw, depending whatever the owner wants. Even though there is nearly a horsepower difference between the two styles, the spicier one only cuts about 5% faster.

 

[wcorey]

@Red97

If a porter ported a saw and it produced less torque than stock, then something is wrong...
Time to find a new porter...lol

While I know what you probably mean, if you wanna get technical...
Actually it's quite possible to have 'less torque' while producing more power, just depends where the torque is on the rpm scale.
Torque is a very misused/abused term in these types of discussions...

 

[Red97]

Not huge gains, but should be a nice work saw.

I am going to try a couple other things on the other one...


The hp/tq numbers listed are taken at the thin red line (8400rpm)

 

[MustangMike]

Nice gains Joe, but it makes me feel good about my Asian 660 making 8.6 Hp.

Re the discussion: Higher HP #s are always good, but a broad powerband is very desirable. When you can combine the two, it is a saw that almost everyone likes. A saw that does not feel like it looses power when there is a slight decline in RPM will be perceived as having good torque.

The feel, and the actual torque #s do not always jive.

 

[Sawrain]

While I know what you probably mean, if you wanna get technical...
Actually it's quite possible to have 'less torque' while producing more power, just depends where the torque is on the rpm scale.
Torque is a very misused/abused term in these types of discussions...

Possible but unlikely here, given the inherent constrains of porting/modifying chainsaws I don’t think we will see too many saws with dyno charts that are completely unrecognisable before/after, that is not to say they don’t have have amazing gains, but that just that you can still see their DNA if it were.

Much more possible with engines built for performance as the scope of modification is just so much greater, but still, torque correlates well with volumetric efficiency, and chasing horsepower normally means chasing volumetric efficiency, which means more torque.

 

[Sawrain]

Most of the old comments were always ported saws "lose low end tq"

And they are still saying it, this is a screenshot from the shack, it is the party line on ported saws and opened up mufflers, that they lose torque.

From this video comes proof that opened up mufflers don’t work, of course there is also a test here that shows they do work, but it was ignored.

I’d rather modify a standard muffler than run a bark box, but I imagine they do perform the intended task.