Another chainsaw dyno...

[Dieselshawn]

Those are nice machines

 

[Red97]

Those are nice machines

I really like my first brake. With the updated electronics. It may take some time but I will do the same with this one. This also has the automatic load valve, where the electronics control the test. That should be fun.

 

[Dieselshawn]

Red97:

How does yours work? Just press start test on the computer screen and the machine makes the saw work?

 

[Red97]

Red97:

How does yours work? Just press start test on the computer screen and the machine makes the saw work?

I run the throttle and the load.

Have the program set to capture a "falling" window.
Max rpm, once i stsrt loading, computer sees the rpm drop and starts recording until they fall below 5k. Then the run is finished recording. Normally a 10-12 second sweep

 

[Dieselshawn]

Red97: My runs goes longer as I have to also verify between 3 gauges, adjust needle valve a tad and then write the numbers down. So it’s not as fast as yours.

The 661 and 660 for example will use about a 1/3 of a tank between runs.

 

[Red97]

Red97: My runs goes longer as I have to also verify between 3 gauges, adjust needle valve a tad and then write the numbers down. So it’s not as fast as yours.

The 661 and 660 for example will use about a 1/3 of a tank between runs.

If you can position all 3 gauges where they can bee seen. Could you take a video and do a sweeping run?

 

[Dieselshawn]

Red97:

Yes I can. Hopefully this week.

Gotta figure how to hold the phone

 

[Dieselshawn]

Here are my gauge locations....

 

[Dieselshawn]

I use both the pressure gauge as well as the scale.

I’ve got enough numbers put down that they’re always at certain psi for certain scale number.

Allows me to verify that the numbers are correct if the scale reading by chance is off.

This machine has been very consistent over many runs with the same saws.

 

[Red97]

Last saw before baby arrives.

 

[Nutball]

I'd like to see one dynoed with just a muffler mod.

 

[Dieselshawn]

Modding a muffler is a timely art. It must be perfect

 

[Nutball]

Modding a muffler is a timely art. It must be perfect

I believe it.

 

[Red97]

I'd like to see one dynoed with just a muffler mod.

5-8% is what the majority come out to.

 

[Nutball]

Sounds about right. I think mine gained about 12.5% in wood, but I expect gains in wood to exceed gains on the dyno. Is that your finding too? Mine is only muffler modded, and I'm quite happy with it that way as strong as it is, but it does feel quite lacking when burying the 24" bar, but it isn't supposed to be a 24" saw anyway. I wish they made a 24" Stihl light in Husqy small mount.

 

[farminkarman]

Last saw before baby arrives.

View attachment 311319
View attachment 311320

That thing has a nice wide powerband. Should make for a very nice saw!

 

[Nutball]

I'd like to see how stock & ported it compares to a stock 590.

 

[Dieselshawn]

On my machine, between a stock 661 and a muff modded triple port 661.

depending on what rpms people cut at.

At 11,000 rpms, 27% gain
At 10,000 rpms, 14% gain
At 9,000 rpms, 15% gain
At 8,000 rpms, 14% gain.
At 7,000 rpms, there is no % over the stock 661 as it won’t go this far.

Stock 661 vs Mastermind ported 661 with triple port muffler.

(I use pump psi when testing as it’s very accurate)

11,000 rpms, 25% 1,200 psi vs 1,600 psi
10,000 rpms 8%. 1,700 psi vs 1,850 psi
9,000 rpms 21% 1,650 psi vs 2,100 psi
8,000 rpms 29% 1,600 psi vs 2,250 psi
7,000 rpms vs 2,300 psi

In the wood, the stock 661 with 7 pin rim did 7.15 seconds in the cut.

The Mastermind 661 did 6.32 seconds. A gain of only 12%

After switching to a 8 pin for the Mastermind, 5.85 seconds was the result. a gain of only 18%.

I noticed the modified saw had to be leaned on harder so it definitely needed some more depth gauge filed off.

Which is why the 8 pin performed better.

We usually find the 7 pin as the best performing rim to use.

Overall, the Mastermind 661 is a powerhouse. It feels strong and has a nice broad power band.

The stock 661 is peaky. It is severely choked up because of the internal baffle.

 

[Dieselshawn]

If you can position all 3 gauges where they can bee seen. Could you take a video and do a sweeping run?

I attempted to do a video of a sweeping run today.

I need to find a stable platform for my phone to stand on.

I tried a metal pole that has weight on it on the floor.

The power pulsing in the garage made the phone shake even though it’s not attached to the dyno.

The phone was 2 feet away from the machine standing off the floor.

 

[Nutball]

Hang it from a couple strings. Or put a mini tripod on a block of air filter foam.