When Vehicle Power Dictates Acceleration - Comments

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Discussion Overview

The discussion revolves around the relationship between vehicle power, torque, and acceleration, exploring how these factors influence vehicle performance under various conditions. Participants examine theoretical and practical aspects of vehicle dynamics, including traction limits, power limits, and the implications of these on acceleration at different speeds.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Mathematical reasoning

Main Points Raised

  • Some participants argue that the maximum possible acceleration of a vehicle depends on the maximum power available, while others contend that torque or force is more directly related to acceleration.
  • One participant emphasizes that for maximizing acceleration, the focus should be on horsepower to weight ratio, particularly at non-zero speeds, suggesting that running the engine close to peak power is crucial.
  • Another participant challenges the idea that acceleration can be framed as the rate of addition of kinetic energy, asserting that this is a different question with a different answer.
  • A participant outlines three common limitations to acceleration: traction, power, and wheelstand, noting that the vehicle can accelerate no quicker than the least of these three rates.
  • Mathematical relationships are presented, showing how traction-limited and power-limited acceleration levels can be calculated and how they interact at different speeds.
  • One participant discusses the implications of torque and power equations in understanding maximum velocity, arguing that the power equation provides more comprehensive information than the torque equation alone.

Areas of Agreement / Disagreement

Participants express differing views on the primary factors influencing acceleration, with no consensus reached on whether power or torque is more critical. The discussion remains unresolved regarding the best approach to understanding vehicle dynamics in relation to acceleration.

Contextual Notes

Participants highlight the dependence of acceleration on various factors, including vehicle parameters and conditions, and note that the discussion involves complex interactions between power, torque, and traction without resolving the mathematical steps involved.

  • #31
I've not read the prior comments , but certainly would have read them before commenting if they'd shown,

so if my remarks are repeat of somebody else's please excuse me.. I'll find them after a while.

No response necessary - i'll catch up...

old jim
 
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  • #32
Greg Bernhardt said:
jim hardy said:
(What ? no Latex in Insights comments ?)
Should be fixed in a month or two. Comment in the forums threads.
Thanks, Cap'n !
 
  • #33
Torque (lb ft) versus speed (mph) versus gear for a 2001 Hayabusa (I own one of these). The crossing points of the lines are the ideal shift points. Peak torque in 1st gear translates into about 1.2 to 1.3 g acceleration (depending on rider weight and weight of gasoline in the tank), at which point it's wheelie limited unless the rider sit and leans forward (otherwise the bike tends to lift the front tire at around 40 to 45 mph if at full throttle).

busatrq.jpg
 

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  • #34
Huh. That graph makes me wonder why 5th gear even exists. There's almost no time in which you'd want to be in 5th.
 
  • #35
Tom.G said:
At the risk of intervening in an apparent theological war,
That's exactly what this thread is. It's big-endians and little-endians all over again, in search of a solutions to a problem that's not be properly specified. With a very few exceptions, the answer is that a good bigg'un beats a good little'n.

I don't know how I boarded this particular train but I only looked at the posting dates when I bumped into the lovely @jim hardy 's name. I bet he'd have a good laugh about this. His last post was in 2019!.
 
  • #36
cjl said:
Huh. That graph makes me wonder why 5th gear even exists. There's almost no time in which you'd want to be in 5th.
If you pay attention to what the gear / up-down display tells you it will help your mpg in long speed restricted stretches. It may not help the boy racer in you but it can save the pennies.
 
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