Another chainsaw dyno...

[sawmikaze]

So are ported echo's the new forum saw to have ?

 

[Philbert]

VERY nice!

Love to see what some electric saws would do. All of the warning labels on chaps mention the 'constant torque' of electric motors. Some of the big STIHL electrics run 3/8 chain, but most run 3/8 low profile.

Philbert

 

[Lightning Performance]

Wow, using something like that would make carb mods SO much easier. Mod a couple of carbs, make a run, change carbs and check out the torque and HP. See where the mods are going. When you go too far, you know where to go back to.

The big carb will give your best peak and more than likely drive like *s-word. The cool factory here is the long load times. No limits on a full tank pull.

 

[Philbert]

Graph on . . . 620 hybrid

OK, I had to look up the difference between 'Horsepower' and 'Torque'. This explanation might help others as well.

Philbert

 

[Red97]

So are ported echo's the new forum saw to have ?

I'm certain once I get my hands on some other ported 70cc the echo will get beat.

But that chassis is rated at 4.45hp stock.

And the stihl is very close to the rated hp.

 

[sawmikaze]

I'm certain once I get my hands on some other ported 70cc the echo will get beat.

But that chassis is rated at 4.45hp stock.

And the stihl is very close to the rated hp.

It's impressive for sure buddy.

 

[Fruecrue]

 

[mgr1]

There are others saws i want to see on the dyno.

Dolkivarna
Scar stroked 395xp
The piped 9010 with 60mm topend
Lee's 60mm 166

 

[CR888]

Everyone needs a saw dyno, very few have the skill & patience to build one properly. Great accomplishment.

 

[srcarr52]

There are others saws i want to see on the dyno.

Dolkivarna
Scar stroked 395xp
The piped 9010 with 60mm topend
Lee's 60mm 166

Lets not break the dyno right away!

 

[Wilhelm]

Always cool to see dyno run graphs, although I read them wrong till You wrote they need to be read right to left.

You need to do a dyno GTG, clock as many saws as possible and make a spreadsheet with stock/ported data.

I want to see a stock PS-7310 with the SLR removed on the dyno, those units are greatly under rated.

Did You get a life insurance policy for Your Dyno?
Somehow all dyno's that I have read about seem to have met a tragic death.

 

[Red97]

There are others saws i want to see on the dyno.

Dolkivarna
Scar stroked 395xp
The piped 9010 with 60mm topend
Lee's 60mm 166

Sounds fun.

Lets not break the dyno right away!

Says 30+ hp might as well test it.

Always cool to see dyno run graphs, although I read them wrong till You wrote they need to be read right to left.

You need to do a dyno GTG, clock as many saws as possible and make a spreadsheet with stock/ported data.

I want to see a stock PS-7310 with the SLR removed on the dyno, those units are greatly under rated.

Did You get a life insurance policy for Your Dyno?
Somehow all dyno's that I have read about seem to have met a tragic death.

Just the saw are right to left. High rpm no load right to lower rpm more load left.

I do plan to have a dyno day.

Eventually do some build offs etc.

I ordered a printer for my current setup. Will print off all the data points. To make graphing easier.

Trying to get this thing all legit.

Chainsaw dyno services lol

Might have to look into dyno life insurance.

 

[Lee H]

Awesome job, Not sure how i missed this thread, like to put one of my Kart saws on it but they
run larger than 7 pin. Suppose i could change that. Also like to see the numbers on my 166
big bore saw.

 

[Red97]

Awesome job, Not sure how i missed this thread, like to put one of my Kart saws on it but they
run larger than 7 pin. Suppose i could change that. Also like to see the numbers on my 166
big bore saw.

I am going to get a 404 sprocket for the bigguns... some are hard to find and only have spurs.

Can you run a 404x7?

All the calculations are on a 2:1 ratio so I will be getting a 404x14 for the jackshaft.

 

[Lee H]

I am going to get a 404 sprocket for the bigguns... some are hard to find and only have spurs.

Can you run a 404x7?

All the calculations are on a 2:1 ratio so I will be getting a 404x14 for the jackshaft.

The one Kart saw i would really like to see the numbers is running a 3/8 11, I can change it at any
time if need be. The 166 is running a 3/8 8 but that can be changed easily enough. Most of my saws
can be altered in any direction.

 

[Lee H]

I can run 404 7 and 404 8, I think i have some Dansco 404 larger but not sure what size.

 

[Red97]

The one Kart saw i would really like to see the numbers is running a 3/8 11, I can change it at any
time if need be. The 166 is running a 3/8 8 but that can be changed easily enough. Most of my saws
can be altered in any direction.

If they are already set up to run the std spline rim. And can run a 3/8×7 That would be great. It is going to read the same power regardless of the ratio by the time I change all the ratios to compensate.

That is where the dyno is only a tool for one part. It can tell the hp/tq and if any changes work.

But in the end it comes down to how well the user can match the chain to the sprocket/power.

 

[Bigmac]

If they are already set up to run the std spline rim. And can run a 3/8×7 That would be great. It is going to read the same power regardless of the ratio by the time I change all the ratios to compensate.

That is where the dyno is only a tool for one part. It can tell the hp/tq and if any changes work.

But in the end it comes down to how well the user can match the chain to the sprocket/power.

That’s so true, have done atv dynoing and for the fun of it we try dyno pulls in different gears and the numbers were nearly identical. In general the chassis dyno guys like the tallest gear so the pull is smoother, from what I’m told, but I also think that is because of wheel spin too,

 

[MustangMike]

Awesome job on both the dyno and the saw, very impressive!

However, the auditor in me has to ask a question. Why is 8.18 below the 8 line on the graph, and likewise 7.2 below the 7 line? Shouldn't they both be a bit above those marks??? Seems like the graph is not perfectly mated to the grid.

Your dyno is awesome not for just showing the peak power of the saw, but also for showing the broadness of the power curve. Very important (IMO) for both work saws and for milling.

I sure wish you lived closer, lots of things I'd like to test! (Various saws, various air filters, various mufflers, etc).

 

[Red97]

That’s so true, have done atv dynoing and for the fun of it we try dyno pulls in different gears and the numbers were nearly identical. In general the chassis dyno guys like the tallest gear so the pull is smoother, from what I’m told, but I also think that is because of wheel spin too,

1:1 Is typically best. But these saws don't have a ton of tq so I doubled it to help smooth the run.