weedkilla
Ain't no guru of nuthin'
Obviously I am talking about using a dyno as a development and diagnostic tool. That's not what chad is doing here. He's giving a saw a run, not doing development work for someone else.
Dyno tested....Mastermind's ported 261cm vs Stock 261cm Gotta see this one.
- Thread starter chadihman
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Mastermind
Work Saw Specialist
Thanks Chad.......for all the hard work you have done. 
Terry Syd
Addicted to ArboristSite
"but without a wide band O2 sensor up the exhaust we just guess that mtronic is doing it's job."
That's why I'd like to get some schematics of what these systems are doing. There are too many assumptions about what is going on, perhaps there is fuel issue, perhaps there is a timing issue. In any case, these systems were designed to work around the EPA guidelines, they were not built for maximalising the horsepower. Perhaps we can do some tweaking if we knew what we were working with.
That's why I'd like to get some schematics of what these systems are doing. There are too many assumptions about what is going on, perhaps there is fuel issue, perhaps there is a timing issue. In any case, these systems were designed to work around the EPA guidelines, they were not built for maximalising the horsepower. Perhaps we can do some tweaking if we knew what we were working with.
Mastermind
Work Saw Specialist
You guys over analyze this stuff......just saying.
My guess would be that there isn't as much magic going on with these chips as we imagine. They are after all, Gen. 1. Processors. What are the claims? Temp, altitude, fuel quality. That's about it. I'm sure they went with reliability over sophistication for their first rodeo.
weedkilla
Ain't no guru of nuthin'
Well..... After we've gone "holy crap that's an amazing gain", there isn't much else to talk about. I've found dyno time addictive in the past, there is always one more thing to try. Perhaps we should have mentioned the bigger dip in the stock power curve.
Really looking forward to similar gains from my 362 in Aug. Stock it is a very fast limbing saw, but it does slow down in the bigger wood. It is a lot more noticeable since I put the dual port muff, etc on the 044.
Stihl says peak HP on the stock 362 C-M is at 10,000 RPM, wonder if Chad's dyno would confirm that.
Stihl says peak HP on the stock 362 C-M is at 10,000 RPM, wonder if Chad's dyno would confirm that.
KG441c
Keith
Do u think direct injection or efi on saws will be programmable?
I doubt the API or an interface will ever be made available.
Mastermind
Work Saw Specialist
When the discussion becomes too technical......the average member is gone.
But you are right.....there ain't much to say.
I'm pretty happy with the way our 261s turn out. I had someone send me a PM asking about how I knew I was done tweaking this saw. How I figured that out sorta. I have no secrets.....if you want to know what timing numbers, etc I use in a certain saw.....just ask. Lots of hard work is the answer.....
My method consists of going two degrees at a time, on a different port at a time, with no other changes, and then testing in wood. I video the cuts and time them to compare.
When I was testing this model I regularly had three or four of them here at a time. I would sometimes do all of them just a little different.....then test in popular cants.
What I post on the threads, and on YouTube is just a very small part of the testing I've done.
That's the reason there are times when I get even further behind. No way I can produce 5 - 6 saws a week and spend days testing a certain model. The testing is the most important thing we do though......without that, our saws would just be so-so....
I know this has to be a lot of work for you Chad and I for one very much appreciate it. Randy asked to see his 660 run in the other thread, if your up for it we are at least in the same state.
Thanks again for putting in all this time.
Thanks again for putting in all this time.
Termite
Time To Launch
And that ladies and gentlemen is why I don't port my own saws. Also, I would rather be in my woodshop making something.
bryanr2
Addicted to ArboristSite
just remember guys, randy's all booked up til mid octoberthat's one heck of an increase.
and now we all have a graph to see the reason.
Ron660
Addicted to ArboristSite
I'm beat but got the testing done tonight. My rpm sensor wouldn't read past 11500 rpms. I'd still like to test up to 13000 if I can get a shaft rpm sensor that will read that high.
Wow Randy this is a hot 261cm.
Ever tested a ported 660? I have one if you'd like to try it.
Poor Chad. His Dyno will be booked through Thanksgiving by the Fourth of July....
Mastermind
Work Saw Specialist
He needs to charge for dyno runs.
bryanr2
Addicted to ArboristSite
yall better book your Mastermind appts. His "stock" just went up even further with the dyno testing. When the evening crowd gets here he will be booked to next spring.
Ron660
Addicted to ArboristSite
I'm beat but got the testing done tonight. My rpm sensor wouldn't read past 11500 rpms. I'd still like to test up to 13000 if I can get a shaft rpm sensor that will read that high.
Wow Randy this is a hot 261cm.
Increase in HP of ported 261, compared to stock 261, at these rpm ranges:
11500 - 43.7%
9500 - 21%
7500 - 12.9%
Factory HP specs for the 261 is 3.8HP which was at 9500 rpms. At those rpms, the ported saw still had a 21% increase in HP. Small price to pay for such an increase in performance!
Mastermind
Work Saw Specialist
You are correct with your percentages.......many times I see them figured incorrectly.
What is it you do again?
What is it you do again?
