paulkish
old fart
Yes
Rotational torque
- Thread starter flattop1
- Start date
paulkish
old fart
Al needs too
Pete_Muller
Moderator
Sorry Al, but if you are comparing a 15/60 to a 15/61, the horsepower at the axle (at 4000 engine rpm) will be EXACTLY the same mathematically.
You will have a touch more torque at the axle, but slightly less rpm at the axle.
PM
You will have a touch more torque at the axle, but slightly less rpm at the axle.
PM
alvin l nunley
Site Supporter
I've often said that very same thing, the HP at the engine, divided by the gear ratio, is always the same as the HP at the axle. In a perfect system of course.
Difference being, and I apologize for not pointing it out, it's producing (all things being equal) the work faster, thus the quicker acceleration. I don't think anybody can argue that a 15/61 will accelerate faster than a 15/60, again, all things being equal. Do I get any points for my explanation i.e. apology?
Great
Except you still completely miss the point of the entire thread.
Ted Hamilton
Helmet Painter / Racer
Let me work some calcs out... I'll post back later.
alvin l nunley
Site Supporter
And you continue to berate me without explaining yourself. Hard to tell which is worse.
This is probably a more appropriate reaction to the post.
Everything you have posted from these 2 posts on have absolutely nothing to do with the subject being discussed. Even less than the post which prompted my reply.
Now the thread has a whole page of whining about being abused, along with a companion thread.
Definetly have the Charlie Brown thing going on.
(The song, not the comic strip)
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Appreciate this Pete.
This thread is about being able to transfer differing amounts of torque while maintaining the same rpm at both the engine and axle.
If you transfer more torque with all else being equal, you have the potential to do more "work".
Ted Hamilton
Helmet Painter / Racer
You can't....that's the point. Everything is a tradeoff. To get more RPM you must do more work. You can fix any one variable and the others must balance like a teeter-totter to achieve it. You can make it "easier" on the rear axle to spin, you'll have more torque, but you'll lose top end speed. Or you can make it harder for the engine to work by making your ratio taller, and it will take longer to get to your higher top speed... The "perfect ratio" is the one that allows you to go fastest in the window of accelleration you have available.... ie, you should accellerate quickly as you can within that window until the point you're falling off the torque curve enough to get beat or you're reaching the rev limiter or max rpm and your accelleration slows. You want as "easy" a ratio that allows for that continual accelleration...the only reason to add mutliple gears is to keep the engine in its' best part of the torque curve... Since we're oval racing and have a limited accelleration window, we can get away with single gear, but i'd still want the shortest gear available (which is actually the literally tallest gear...) that gets the job done. The wheel size / gear size end of this exercise is a balance to the piston force downward acting on crank offset... It's all a tradeoff, and you can't keep rpm and magically gain torque. The torque available is a constant, based on the dynamic power of the motor, based on its' breathing efficiency and combustion efficiency. The gear and tire ratio are simply trying to make best use of whatever that available torque is... Depending on your torque curve, it's theoretically possible to have 2 ideal ratios where one slightly taller ratio falls off at end of straight, and one slightly shorter ratio accellerates better off the turn, making for both karts traversing the straight in the same net time, but accellerating at different rates and different times. This would typically be a "paper clip" track. A track that is more "elliptical" would favor a single ratio. In the paper clip track, I'd probably choose the shorter ratio and try to pass early and mess up the other guys' line (without contact, of course) to further magnify the torque window difference... Or maybe I'm on crack and don't understand it at all....but that's how its' worked out in my head from my reading, and engineering classes...
paulkish
old fart
Without reading any more of your post and quote I think you missed the point.
His post which you quoted said nothing at all about a change in rpm.
Accepting your speech about everything being a trade off then there MUST be other trade off's you not taking into consideration, being he clearly stated there was "NO" change in RPM.
... butt I'm throwing that in the mix and saying I don't understand it all and am throwing in in the mix because I think your not comparing apples to apples. maybe ????????????
What I see interesting is the thread seems to be discussing changes in the efficiency of how torque is transferred.
Yep there are trade off's but I think you may not be bringing in the correct trade off's being talked about. ????????????
This is a learning process and i'm proly throwing out a dumb question or observation in class. ...
edit: I'll assume the amount of torque cannot be altered in the discussion and it will do the exact same work.
I'm thinking the amount of torque is not changed, only where the torque does its work is changed. ????????????
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Definitions
Torque
Force at a distance.
1 pound at 1 foot equals 1 pound/foot
Power
Force at a distance with a relation to time.
1 pound moving 1 foot in 1 second equals 1 pound/foot/second
Horsepower
Force at a distance with a relation to time, compared to a known quantity.
550 pound/foot/second equals 1 horsepower
Torque
Force at a distance.
1 pound at 1 foot equals 1 pound/foot
Power
Force at a distance with a relation to time.
1 pound moving 1 foot in 1 second equals 1 pound/foot/second
Horsepower
Force at a distance with a relation to time, compared to a known quantity.
550 pound/foot/second equals 1 horsepower
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paulkish
old fart
Am I wrong thinking this thread is about where the "work" is applied, to operate in total, within the workings of the mechanism and not really about how and why an increase or decrease in the amount of work available occurs?
I think the total amount of "work" made available to be used and how it's used are two completely different things.
And I also think the ability for a mechanism to efficiently move "work" from one place to another is also dependent on how much "work" you cause it to move. You can overload the efficiency of the mechanism by causing it to handle excessive work in any of it's parts.
Those parts in our case can be either levers, chains, gears and bearings or tires, G forces and grip.
Fast and efficient for what your racing will change accordingly along with driver input.
It doesn't matter how efficient you make the mechanism's of what you race if your driver does not know how to use them in an efficient manner.
Isn't it about how the "amount of work available" gets used in the mechanism prior to the mechanism's "end point" of use?
Isn't the amount of "work" available at the end point dependent on effort to operate what's transferring the work?
Do the three above questions lead to reasons why output from equal ratio's are not necessairly equal?
Wouldn't any change in the design of what ever is transferring the "work" from one place to another also change what "work" is available at output?
... hey I already said I don't under stand it. ...
... thanks for the thread and fun thunkin and conversation, I need nuther coffee. ...
I think the total amount of "work" made available to be used and how it's used are two completely different things.
And I also think the ability for a mechanism to efficiently move "work" from one place to another is also dependent on how much "work" you cause it to move. You can overload the efficiency of the mechanism by causing it to handle excessive work in any of it's parts.
Those parts in our case can be either levers, chains, gears and bearings or tires, G forces and grip.
Fast and efficient for what your racing will change accordingly along with driver input.
It doesn't matter how efficient you make the mechanism's of what you race if your driver does not know how to use them in an efficient manner.
Isn't it about how the "amount of work available" gets used in the mechanism prior to the mechanism's "end point" of use?
Isn't the amount of "work" available at the end point dependent on effort to operate what's transferring the work?
Do the three above questions lead to reasons why output from equal ratio's are not necessairly equal?
Wouldn't any change in the design of what ever is transferring the "work" from one place to another also change what "work" is available at output?
... hey I already said I don't under stand it. ...
... thanks for the thread and fun thunkin and conversation, I need nuther coffee. ...
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paulkish
old fart
A ratio is a ratio. Totally true.
But it doesn't matter if your mile long rope is 1/4" thick or 1" thick, the work you put into it via your mussel powered hand is not going to give you a different result at the end of the rope.
But shorten the rope to 6' long and the outcome at the end of the rope will change.
But it doesn't matter if your mile long rope is 1/4" thick or 1" thick, the work you put into it via your mussel powered hand is not going to give you a different result at the end of the rope.
But shorten the rope to 6' long and the outcome at the end of the rope will change.
paulkish
old fart
I'm thinking and hoping what I asked in the last two threads is right on the money with the jist of this thread and is not hijacking it?/??
I really think and again hoping knowing I don't understand the subject well, i'm at least now understanding the jist of the reason for the thread.
I really think and again hoping knowing I don't understand the subject well, i'm at least now understanding the jist of the reason for the thread.
It's been stated on this forum, where there is confusion, there is money to be made.
The confusion is enhanced by trying to apply the phenomena to applications much different than where it has been observed, with the outcome being that doesn't appear to work in my situation, so it cannot be working in the scenario described.
To see the benefit, you must use in the method as it is described.
The differing size drivers as part of the same ratio phenomenon is primarily observed as a 4 cycle stock type industrial engine pressed into service as a racing powerplant in a momentum type oval track race.
I have not observed this discussion in sprint type applications of this same engine, although I feel some benefit can, and has been found, although not attributed to this phenomenon.
Nor have I observed these discussions in 2 cycle or open 4 cycle gearing conversations except to try to disprove the theory in the arena where it is observed.
The confusion is enhanced by trying to apply the phenomena to applications much different than where it has been observed, with the outcome being that doesn't appear to work in my situation, so it cannot be working in the scenario described.
To see the benefit, you must use in the method as it is described.
The differing size drivers as part of the same ratio phenomenon is primarily observed as a 4 cycle stock type industrial engine pressed into service as a racing powerplant in a momentum type oval track race.
I have not observed this discussion in sprint type applications of this same engine, although I feel some benefit can, and has been found, although not attributed to this phenomenon.
Nor have I observed these discussions in 2 cycle or open 4 cycle gearing conversations except to try to disprove the theory in the arena where it is observed.