PAST CT GTG 2016 May 7th

[malk315]

So I finally booted up the dyno electronics and laptop to start looking at data. We did a total of 34 different saws with 150 runs of data collected -- an average of about 4 runs per saw.
I checked load cell calibration on the bench to see if it held up after such a beating and it remains accurate to about 1/100th of a ft-lb. of torque and remains linear. Resolution is about 1 oz.

Since Randy didn't make it to the event and I think he really wanted to, I'm going to send the first graph to Randy which is a run of my 1991 262XP with 87 carb that he ported about a year ago.
I'll also send him the bone stock MS460 that we ran to help decide the numbers were reasonable because a bone stock MS460 is rated for 6HP at somewhere around 9000 or 9500 RPM if I remember right from Dan checking the Stihl specs. The data for that 460 shows right around 6.0 when you look at the points in the power band.

I'll also send along data to others -- I'd like to find a way to draw a trendline on there to help visualize the powerband as there is still quite a bit of variance since we have to deal with the brake pulsations creating this wild frequency in the data.
What is shown on the red/green/yellow displays is exactly what's in the graphs.

Note that the scales for graphs on left and right for torque and HP are chosen by the graphing tool -- at some point I need to find out what range to force the HP to be at versus torque to make all graphs look consistent. For now -- be careful to look at the scale for each graph the range it chooses for one might make you think another is lower or higher -- it's all relative to the scale on the side.

 

[SOS Ridgerider]

Didn't I say to get yer arse down here? I think that was you.
Once you go to one of these if the guys are anything like the group at NY or CT you won't miss again!

Guilty as charged! Instead of coming down for the fun, my arse was stuck at work.

 

[MustangMike]

Eric, you also get the video photography award! Great Job. FYI, any of the Stihl saws you see being run that have a band of white tape on the side handle are my saws. That is how I can find them across the lawn mixed in with a dozen others!

And if you and Randy don't mind, I would love to see the run results for that 262. They were all very strong.

 

[malk315]

Eric, you also get the video photography award! Great Job. FYI, any of the Stihl saws you see being run that have a band of white tape on the side handle are my saws. That is how I can find them across the lawn mixed in with a dozen others!

And if you and Randy don't mind, I would love to see the run results for that 262. They were all very strong.

No worries Mike -- once I get to your batch of runs I'll be sending you all of your graphs and I'll see what Randy says when he sees everything I posted on the PM thread we've had going since back in November when the Dyno idea was hatched
I included not only the MS460 bone stock but I also included Bill's stock 262 which is a more interesting comparison.

 

[MustangMike]

As much as I'd love to see that stuff ASAP, get some sleep Eric, you are going above & beyond!

I still almost can't believe we were able to do this, GREAT STUFF, looking forward to it. You guys are amazing!

 

[malk315]

I posted an update on the dyno thread I'd like you guys to have a look at.
It explains how we get from noisy data on the load cell to a usable curve.
With what we've got we have the graphs from this weekend which are not too bad and usable.
I want everyone to understand since we're starting with noisy data that is why some of the graphs have some variability that can be a little ugly to the eye.
It's the best we could do on short notice and I'm psyched we were able to get some usable data.
I hope it's consistent enough to tell the variability of for instance the several 350's we ran -- I'm thinking some can be so close it could be tough to tell.

One thing we did learn for sure -- a restrictive muffer will choke a 350 real well! Also learned no air filter at all can make a big difference -- we took that saw of Al's through 3 different filter scenarios from restrictive to none.
Also tuning and such clearly makes a big difference.

Hopefully when we spend more time we can get the dyno even better in terms of variability!

I'll keep working through sending the graphs we got to all saw owners.
I may make them available as web links so you guys can hover the mouse over points to see the point and what RPM it goes with.
If anyone wants the raw CSV file to play with plotting the data in excel or something similar just ask.
I haven't found a good way to overlay a trend line on the web graph tool I'm using but the line is pretty easy to envision on most graphs.

I think this will be about it for me tonight. Getting tired!

I really enjoyed this weekend -- was great to combine my nerd hobby of computers / hardware / software / electrical with a passion for chainsaws and making chips fly.
Thanks again.

 

[Moparmyway]

Here are the graphs that Eric sent to me for the no-decomp 066

 

[Moparmyway]

Here are the graphs from the 661

 

[paragonbuilder]

Eric, why in the 066 graphs and one of the 661 graphs does the torque scale change? It makes it look like there is more torque than hp.


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[mdavlee]

That's cool to see. The 066 made almost the same torque but not the top end hp.

 

[drf256]

Guys,

The torque is really what matters. The HP is calculated.

Bothe the torque and HP are dependent on the brake actuation. The smoother the brake was applied, the more accuracy.

 

[Moparmyway]

That's cool to see. The 066 made almost the same torque but not the top end hp.

I wonder if less compression would help the high end ?

You wouldn't happen to remember how much you cut off the base of that one ?

 

[RI Chevy]

Could be like the current trend in diesel motors. They are lowering the compression and gaining more Torque and Horsepower and getting cleaner emissions. Higher RPM's. Older doesel engines were 22:1 compression. Newer diesel engines are 16.5:1.
Maybe? I am just thinking outloud.
Really cool experiments with that invention though!

 

[paragonbuilder]

Guys,

The torque is really what matters. The HP is calculated.

Bothe the torque and HP are dependent on the brake actuation. The smoother the brake was applied, the more accuracy.

That's kinda true Al, but torque is unusable without rpm, hence the calculation that we call hp.
You can see this with the huge torque at the end of the Dyno run, but no saw cuts good at 5000 rpm that I've run.


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[paragonbuilder]

Could be like the current trend in diesel motors. They are lowering the compression and gaining more Torque and Horsepower and getting cleaner emissions. Higher RPM's. Older doesel engines were 22:1 compression. Newer diesel engines are 16.5:1.
Maybe? I am just thinking outloud.
Really cool experiments with that invention though!

I think that's more because of adding turbos. They are stuffing too much air in there for high compression.

 

[drf256]

That's kinda true Al, but torque is unusable without rpm, hence the calculation that we call hp.
You can see this with the huge torque at the end of the Dyno run, but no saw cuts good at 5000 rpm that I've run.


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I having a hard time putting it in words Dan.

I guess it's the HP in the usable range.

My leaned out 360 that made 8hp at 13,000 rpm was a useless powerband.

 

[mdavlee]

I having a hard time putting it in words Dan.

I guess it's the HP in the usable range.

My leaned out 360 that made 8hp at 13,000 rpm was a useless powerband.

With the right chain that wouldn't be useless. Maybe with some nitro it would be 10 hp there.

 

[RI Chevy]

I think that's more because of adding turbos. They are stuffing too much air in there for high compression.

True dat. But even stock OEM single turbo engines are improving and enjoying more HP and Torque through these advancements in technology.

 

[drf256]

With the right chain that wouldn't be useless. Maybe with some nitro it would be 10 hp there.

It's not real Mike. It was totally leaned out and made 16,000 rpm with no air filter.

The fuel couldn't keep up with the air with no filter. There was a lot of spitback that didn't get sucked into the motor.

But I now know that a stock 036 boot flows more than enough air for the saw.

 

[Definitive Dave]

I having a hard time putting it in words Dan.

I guess it's the HP in the usable range.

My leaned out 360 that made 8hp at 13,000 rpm was a useless powerband.

Lets get a balsa cant for the next GTG and let that sweet 360 sing through some wood with a race chain
regardless of the particulars getting an MS360 to 8hp is badass!!!
other opinions on this matter will be summarily disregarded