Another chainsaw dyno...

[huskihl]

Need to get around to trying it.

But curious to find out the hp% gain vs the cut time % drop.

Is 25% more hp 25% quicker cuts?

Fun fun.

25% more power seems to be more than 25% faster times. Don’t know how, but it sure seems that way

 

[Red97]

Example

4.5 hp to 5.63 = 25% power gain


36 sec to 27 sec = 25% quicker cut

That 11 sec seems a lot harder to get than the 1.13 hp?

Sure would be nice to figure out the ratio.

 

[huskihl]

Example

4.5 hp to 5.63 = 25% power gain


36 sec to 27 sec = 25% quicker cut

That 11 sec seems a lot harder to get than the 1.13 hp?

Sure would be nice to figure out the ratio.

I was going more by cc’s than hp.

In my experience, 25% more cc beats up on 25% faster times

 

[Terry Syd]

Perhaps it has to do with the cutting angle on the chain. When you can produce more power, you can use a bigger cutting angle (lowered rakers) to take a bigger bite of the wood.

That's why the dyno is so good. You can eliminate the chain and wood and just look at the powerband. When you get the best powerband you can, then tweak the chain to the engine and the wood.

 

[Red97]

I was going more by cc’s than hp.

In my experience, 25% more cc beats up on 25% faster times

You talking both ported saws?

Ported 046 vs ported 660 that is roughly 25% cc jump.

 

[Ryan Browne]

Big T spinnin Wu TANG!!!!!!

I've never been at the intersection of yoga clothes and Wu-Tang Clan before. Gotta say, nice neighborhood.

 

[Deets066]

Example

4.5 hp to 5.63 = 25% power gain


36 sec to 27 sec = 25% quicker cut

That 11 sec seems a lot harder to get than the 1.13 hp?

Sure would be nice to figure out the ratio.

Just like cars at the drag strip. It’s not hard to get a car to a 10 second run. But it’s starts to take a lot more HP to gain time after that.

 

[Red97]

Just like cars at the drag strip. It’s not hard to get a car to a 10 second run. But it’s starts to take a lot more HP to gain time after that.

Exactly. Muffler mod and timing advance is good for a nice drop in cut times. Is it 1:1 For the first 20% then more like 20% more power to gain another 10% quicker cut time ?


I need to get a few more saws on the dyno.

The torque I thought I felt in some of these bigger cc hasn't been found on the dyno.

I know I don't pull a saw much if any below 8k in a bucking cut on purpose.

So far the smaller saws have had more hp, and tq across the board until under 7k.

I have a hard time seeing the power under normal in cut rpm making a difference.

Maybe if you start the saw in the wood it may make a difference. From idle to max rpm while dogged in.

From full throttle over the wood, I can't see the tq/hp made at 7k and below coming into play. On a saw tuned to 13k and working in the 9k + rpm in the cut.

 

[Bigmac]

The times when the lower end power is needed is falling cuts, were you would be off and on the throttle in the cut, and long bars were you needed to accelerate the chain in the cut from an idle. But they are minor.

 

[Red97]

The times when the lower end power is needed is falling cuts, were you would be off and on the throttle in the cut, and long bars were you needed to accelerate the chain in the cut from an idle. But they are minor.

I could see that.

I'll have to grab the tach and see where the clutch actually grabs with some load applied.

Like having the chain set and powering up from idle.

 

[CR888]

Often we see 'same bar/same chain' cut tests too compare powerheads & eliminate the variable of different chain. But...to get the most from a bigger or more powerful saw you really need to match the chain to the powerheads. Racing chains vary quite a bit from a 3cube chain to a 5cube etc. The dyno cares not one bit about this and purely judges a saw right off the crank.

 

[big t double]

bring tha muthafuckin ruckus

Big T spinnin Wu TANG!!!!!!

goddamn I got a nice rack. Killin the ones and twos.

outside of that...I have no clue what none of this *s-word is. Cept that joe built a cool machine.

 

[Red97]

This is a fun one.



Thoughts?

Any clear winner?

 

[Stump Shot]

Need to get around to trying it.

But curious to find out the hp% gain vs the cut time % drop.

Is 25% more hp 25% quicker cuts?

Fun fun.

Lots of wood variable there, I've gotten as much as 50% better cut times in a certain piece of wood, and there's no way power was increased by that much. Still would be interesting to see what you come up with.

 

[RalphK]

This is a fun one.

View attachment 243755

Thoughts?

Any clear winner?

No clear winner as I see when it come to in the cut power rpm.

 

[Philbert]

What would ideal curves look like for a work saw (and why)?
For a race saw?

Thanks.

Philbert

 

[Red97]

What would ideal curves look like for a work saw (and why)?
For a race saw?

Thanks.

Philbert

Going to imagine a race saw to look more like this...

Piped, 65cc motocross engine

 

[cuinrearview]

Are the little waves in the curve from you applying load?

 

[Deets066]

This is a fun one.

View attachment 243755

Thoughts?

Any clear winner?

That’s about as close as it gets there. What saws?

 

[Bigmac]

This is a fun one.

View attachment 243755

Thoughts?

Any clear winner?

Looks pretty even, going to guess the yellow curve is a larger saw, probably pick the lightest of the two as the winner! LOL