Yes your load changes. But by how much 2%? 10%? Is the load ever double? 10–15 times more like a saw is?
I’m not trying to argue but you guys don’t appear to be getting what I’m talking about
400c Rumors… or just internet trolls.
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I’m not trying to argue but you guys don’t appear to be getting what I’m talking about
Recreationally speaking within sleds , trail riding to deep powder or cross country 35-40 % variance easily . Racing sled either ice ovals or xcross or snow cross easily events easily 45-60% Drag racing events easily 60-80 % . Were speaking of 600 cc to 1000 cc twin or triple cylinder & above liquid cooled engines developing anywhere from 150 to 1000 hp . I believe , I have agreed more than once that actual real world testing is required to validate any form of dyno testing brother , within any of the cycle or sled applications . So where have I or we missed the boat bud ? A saw idling through cedar vs milling red oak or a trail sled running down a groomed trail vs a Mountain sled @ 3000' in 8' of virgin powder . Its all apple to apples within engine demand & loading variables or transitions !
I absolutely get what your saying and Indont disagree.
What really loads a sled or a bike up is complete traction. A bike for instance ran on asphalt will need several main jet sixes richer jetting because there is no wheel spin. Same story for a sled at the beginning of a ice oval race vs the end.
A saw dogged into a oak log vs cutting 4x4 softwood is the same story.
What's sets Kevin's saws apart from many is the have nice "back up" torque off peak and a flat HP curve. Much the same at what sets a good snowmobile motor apart from a poor one.
Yep , more than a few jetting changes within a 500 mile Enduro Event . Yep my 850 Patroit Polaris Axis will lock up my 3" paddle track , in deep powder . Thank God for fuel injection & anti knock sensors . I never liked peaky horsepower curves on cycles . Had a few that required repiping & jetting my 125 Hondaka Wombat was the worst . Another 250 Cz was not much better , very temperamental Enduro . My 1969 H1 was the only road bike that was a little peaky also , once on the pipe though lookout !
And just so folks know, I’m not discrediting Joe’s dyno. I think it’s an awesome tool to check where you made gains and to see the running characteristics on paper. I actually have a saw down there right now. My only argument is that when you see a change in the dyno, it’s difficult to tell if it’s going to cut smaller or bigger wood faster or slower
Any saw you build will cut just fine , just saying brother !
Again, I only mentioned sleds on a flat track. The I 500 in the Soo, (because it’s as quantifiable as I can make it. Too many variables while trail riding).One lap empty, and then another lap with 500 pounds on it, and then maybe another lap with 1000 pounds on it. and then start over empty again lol. But you can’t know ahead of time how much of a load is going to be put on it, just like sending a saw off to someone who is going to run it differently than you. Build that sled using a dyno only and see how you fare.
Oh, and you can’t know ahead of time how many picks the pit crew is going to put in the track, because you don’t know how the saw owner sets up his chains.
The only loading factor Kevin is resistance to motion Kevin actually lol . The official fuel tank capacity is 13 usg. or just over 109.2 lbs . Add another gallon of track slider coolant , you still under 120 lbs from empty to full . Not really a factor on 150 hp + sled .Therefore , traction is the key point of revelance . Frictionally speaking smooth ice surface offers much less resistance or drag coefficient . Ice crystal formation offers the 1st added friction , followed by deeper granular snow usually 2" within the 250 mile marker. Finally much deeper & denser 4-5" snow & dirt . Terminal speeds drop by 5-8 mph by the 250 mile marker. Peak engine rpm can drop by 400-800 rpm due to chassis & clutching & track degredation . 2-3 Arimid fiber belts per race minimum . P.S. Average 137 inch track has 250 studs & pick combinations . 134 inch track 175 Studs & pick combo . Studs provide lateral cornering stability & picks give added straight line acceleration potential. These sleds really do hook up , not much track slippage until later laps . Finally usually within the last 150 miles deep ruts & warmer temps carbides are gone & studs are worn cornering suffers & throttle response aids with diamonding the corners , however track slippage increases (slip & catch) often which adds more engine loading. The average recreation sled trail or powder run 50 - 75 studs & picks . Anyhow , I agree with your accertion that actual cutting is the best way for the average weekend warrior to tune his saw to his type of cutting application . If he is into Hotsaw competitions added dyno testing may be beneficial , since it readily verifys any performance gains or loss's quite clearly , once a bench mark has been established . I know what your saying , just believe valid dyno tests are strong indicators of engine improvements or deficencies . Either way respect your knowledge & opinion brother !
Until they can dyno the force of the chain in the wood, it is just a number.
One thing North, at the start of the race with fresh track studs loading will be the highest. This is because the track is not spinning at all. Say you could adjust primary clutch weights on the fly. You wpuld actually need a bit heavier weight at the start of the race vs the end. All other factors unaccounted for of course.
Same story with a dirtbike on asphalt vs dirt.
They can, you can load the engine however much or little you want. Stall the engine out if you're so inclined.
I wish kart racing was as simple as chainsaw set ups. It is 100 times harder IMHO.
Chainsaw racing back in the day was a piece of cake compared to kart racing.
Set ups and weight etc all do change on karts. Way more involved.
Torque and HP is all involved too in every selection of parts, porting and set up.
Chainsaw racing back in the day was a piece of cake compared to kart racing.
Set ups and weight etc all do change on karts. Way more involved.
Torque and HP is all involved too in every selection of parts, porting and set up.
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Actually no weight changes required , rather stiffer spring rates apply . Yes fresh studs & picks supply the greatest loading as i mention as "hook up " . I prefer 160/310 weight springs on 600 cc & 160 / 340 on 800+ sleds ! Weights govern engagement rpm & transition of the spider or helix ramp indexing location as your aware . But your in the right neighbourhood brother . P.S. A lot of the 600 pro open sleds (Triples) actually ran in the Formula open 800+ class , which is dominately (Twins) . The 600's breath very well at high rpm where as the majority of the Big Twins have rev limitors , makes for a very interesting & competitive race . When the track begins to deteriorate , the abundant torgue of the twin cylinder sleds becomes apparent . During the time trials or shorter lap Sprint ovals the Triples dominate !
I always proffered heavy weights and a moderate spring over lighter weights and a heavy spring. Although I was dealing with
big bore twins. Triples are a different animal.
I'am just the opposite , pretty well all my Racing was within 440 , 600 & 650 Triples . These engines were much more torgue sensitive than todays big twins . Weights were much more critical back in the day , especially with the smaller displacement sleds ! Today helix angle & transition phase is much more important on the driven clutch 50/30 helix angle I find the most beneficial in ice oval phase transition where as 50/40 is better in mountain sled or deep powder . I have machined hundreds of drive clutch & driven clutch faces & sheaves to ensure optimium not just proper belt alignment back in the day . Today numerous self aligning bearing adders to ensure the chaincase deflection under extreme racing conditions or mountain sled usage at elevation with 4" paddle tracks was maintained within tolerences . Your absolutely correct , the Triples of the 70's 80's 90's were a beast to calibrate carburation & dial in the clutching & suspension offset on Oval tracks !
Not the same. Kind of like rear wheel horsepower on a car. It only matters what force the chain is applying at the wood This is why a dull or sharp chain make a difference.
yes dyno data , to non experienced operator or tuner can be misleading . I agree actual real world testing only validates , if the dyno pulls are indicating an appreciable improvement within the final product efficiency . I would hazard to say Kevin other than within a Milling saw application where a strong torgue curve is paramount . That during felling , limbing & bucking a balanced saw with a flatter hp curve & broader rpm duration torgue curve would be beneficial . What says you brother ?
No idea. . There’s no doubt that the dyno gives a couple firm numbers, but it takes more studying than what I’ve been able to do in the last 5 years to be able to determine which curve actually cuts wood faster or better.yes dyno data , to non experienced operator or tuner can be misleading . I agree actual real world testing only validates , if the dyno pulls are indicating an appreciable improvement within the final product efficiency . I would hazard to say Kevin other than within a Milling saw application where a strong torgue curve is paramount . That during felling , limbing & bucking a balanced saw with a flatter hp curve & broader rpm duration torgue curve would be beneficial . What says you brother ?
Yeah , it takes time to use the data effectively . I believe within a saw proper chain selection (pitch) & sharpness & tuning is more inportant !
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