rpm

Good to know, Gary & Mike. Thanks for your input to the discussion.

So...assuming there was an advantage (worthy enough of the investment to balance the rotating assembly with the clutch, etc) that resulted in add'l rules restricting yet larger/heavier clutches....there would continue to be an advantage today with the 206 (at least on momentum tracks.)
 
There is indeed an advantage to balancing.On the old flatheads there was a a measurable change in rate of acceleration through the selected rpm range of the engine. It was quite a "fishing expedition" to determine the what bobweight % for what rpm range but once that was determined you could effect a noticeable change.Any inertia dyno or waterbrake with some simple software has the ability to measure point to point elapsed time.The engines I tested that had the best acceleration rates through the power band did NOT always show the highest horsepower and torque but I can tell you which ones raced better on a sprint track!
 
I did some track testing with the very heavy Titan clutch last Tue night on a LO 206 with a GREEN SLIDE but I want to do several more test before I come to a conclusion. Back to Back to Back testing takes a lot of time and effort.
The Titan clutch weighs 2 pounds more that the Hilliard clutch I am comparing to.
 
Steve Vermeer said:
The engines I tested that had the best acceleration rates through the power band did NOT always show the highest horsepower and torque but I can tell you which ones raced better on a sprint track!
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It sounds like you're saying you had engines with less horsepower that accelerated faster. Am I reading you wrong.
 
Been thinking about the weight for added momentum. Looks like a larger brake rotor or steel thick gear guards could also add to momentum albeit on the axle instead of on the clutch. Steel wheels and inner liners, ala nascar, are also possibilities. I guess it just comes down to where the diminishing returns kicks in.
 
Steve Vermeer said:
Engines that show a big peak power number or, a big peak torque number don't always race the best so, yes.
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My dyno chart shows a power under the curve number, that's what can win you races.

The engine with the highest torque readings, across the range, is going to win. I often see people talking about how their engine puts out a peak horsepower reading, but that doesn't tell the whole story. If you don't have the torque to get off the corners, or the torque to get the top speed to where you want it, a high peak horsepower number may do you no good.

of course it depends on a whole bunch of other things, but this is essentially correct. On my dyno chart I also had the total horsepower in different ranges. There are some tracks where you spend a large majority of your time in these different ranges. A lot of tight turns type track might favor one curve where a more open track might favor another type curve. People are always suggesting different cams for different tracks, a good example.
 
Not so sure I agree with your thoughts onadded component weight . My thought on the added clutch weight when still hooked up would help engine better maintain RPM and momentem thru the turn . I don't see your theory of added component weight doing anything except slowing down acceleration.
 
Elmer Patterson said:
Not so sure I agree with your thoughts onadded component weight . My thought on the added clutch weight when still hooked up would help engine better maintain RPM and momentem thru the turn . I don't see your theory of added component weight doing anything except slowing down acceleration.
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Any weight added to rotating assembly slows acceleration, whether it be on the clutch or on the axle. I was simply responding to posts about rule changes to limit clutch size. Myself, i like the lightweight components for the tracks i race. However, I can see where maintaining momentum may result in better lap times than quickly loosing and then regaining. Stop watch will show whether the weight fits your total program.
 
My other thought on weight of components on the axle has to do with diameter that the weight affects the inertia of the system. Even though axle spins slower, the larger diameter may help hold momentum better than on clutch.
 
I think you're all taken too narrow a view.

I totally agree with everything you're saying, if you're not connecting these things to a kart and driver. From an idle, a lighter clutch will accelerate faster than a heavier clutch, but when they lockup, and they're accelerating a kart and driver, their influence on acceleration becomes almost immeasurable.
.
 
alvin l nunley said:
I think you're all taken too narrow a view.

I totally agree with everything you're saying, if you're not connecting these things to a kart and driver. From an idle, a lighter clutch will accelerate faster than a heavier clutch, but when they lockup, and they're accelerating a kart and driver, their influence on acceleration becomes almost immeasurable.
.
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im·meas·ur·a·ble - (adjective) too large, extensive, or extreme to measure.
 
alvin l nunley said:
I think you're all taken too narrow a view.

and they're accelerating a kart and driver, their influence on acceleration becomes almost immeasurable.
.
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Remember Al to divide the kart and drivers weight by the gear ratio and consider that rotating mass is 5 times more important than static mass..................... immeasurable acceleration you say ?????????

Steve
 
JimEli said:
im·meas·ur·a·ble - (adjective) too large, extensive, or extreme to measure.
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Yes, the difference is too extreme, in this case extremely small, to measure. Maybe not the perfect use of the word, but I think it makes my point. Thanks for the heads up.
 
I might come closer to agreeing with you guys but consider this .one acceleration is off the corner with clutch at lock up . Minimmal drop in RPM at max torque @3450 RPMs like I posted earlier the Driver has their foot on the accelerator and is riding the brake thru the turn . A whole lot diffrent then acceleration from a slow rolling start . The larger and hvy. Clutch keeps momentum up .
 
Elmer Patterson said:
The larger and hvy. Clutch keeps momentum up .
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If I concede that the larger clutch helps with momentum, you have to concede that it also hurts on acceleration. Mother nature never gives it all.

I will concede that the heavier clutch, from Pete Muller's article on clutches, holds the engine better when it's supposedly locked up. (It always slips some) More power to the axle.

If you have any doubt, consider the Yamaha engine with and without a clutch. The clutch Yamaha is capable of 15,000 RPM, the Direct drive Yamaha is capable 17,000 RPM. The lower gear ratio you run with the direct drive cannot account for that 2000 RPM increase. Gearing, within normal limits, will never allow the clutch equipped Yamaha to reach 17,000 RPM. My contention; the direct drive just gets more power to the axle.
 
alvin l nunley said:
Yes, the difference is too extreme, in this case extremely small, to measure. Maybe not the perfect use of the word, but I think it makes my point. Thanks for the heads up.
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Not to get into an argument, but the meaning of "immeasurable" is too large, extensive, or extreme to measure. Or, so large or great that it cannot be measured or known exactly. I believe that is the exact opposite of what you were trying to convey.

http://dictionary.cambridge.org/us/dictionary/english/immeasurable
 
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