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What is the link between torque and rpm?

digitalbliss

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Torque is NOT acceleration. It is force, twisting force to be more specific. I don't know anyone that uses a torque wrench for acceleration. It's used to put a specific amount of forcce on a bolt/nut. That bolt/nut then continues to have that much torque even if it it no longer moving.

Horsepower is not top speed either, HP is the amount of work (force x distance) that can be done over a certain amount of time
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vavaroutsos

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Torque is NOT acceleration. It is force, twisting force to be more specific. I don't know anyone that uses a torque wrench for acceleration. It's used to put a specific amount of forcce on a bolt/nut. That bolt/nut then continues to have that much torque even if it it no longer moving.

Horsepower is not top speed either, HP is the amount of work (force x distance) that can be done over a certain amount of time
I think @cbrenthus was trying to make the layman's point that more torque at the wheel will produce more acceleration (a=f/m) while more horsepower at the wheel will produce a higher top speed, all other things being equal.
 
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Joe98

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So, Wrangler "A" can reach peak torque at 4,800 rpm and Wrangler "B" can reach peak torque at 3,500 rpm. What does that mean as I try to get over that rock?
 

Raylan Givens

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So, Wrangler "A" can reach peak torque at 4,800 rpm and Wrangler "B" can reach peak torque at 3,500 rpm. What does that mean as I try to get over that rock?
It doesn't mean anything. Tourqe lower in the power band is preferable, peak numbers are not really that important unless you are just want bragging rights.
 
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Joe98

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So in the perfect world we would like high torque at low rpm? Yes?
 

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Joe98

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Or: 2 Wranglers weigh the same. They need the same amount of torque to get over a rock. One does it at a higher rpm than the other. What does that mean to the driver?
 

hutchman

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So in the perfect world we would like high torque at low rpm? Yes?
Probably.....increasing torque at low rpm increases power at the same rpm. A peaky, high rpm drag racing motor will not work well for low rpm rock crawling. It all depends on the application requirements.
 

hutchman

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Or: 2 Wranglers weigh the same. They need the same amount of torque to get over a rock. One does it at a higher rpm than the other. What does that mean to the driver?
The second one breaks an axle......?

It's really very simple.....increasing torque gives you more power. Increasing rpm gives you more power. You need more power to increase the rate of doing work.
 

hutchman

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It doesn't mean anything. Tourqe lower in the power band is preferable, peak numbers are not really that important unless you are just want bragging rights.
Raylan, I'm watching "Justified" right now! One of the greatest shows ever.

Now, back to the discussion.
 

TA1ton

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@Joe98; check out this video:



This guy has some really good videos on the basics of how engines work. Hope it helps!
 

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Joe98

Joe98

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Very good video thank you!

So, I think that a Wrangler with more torque means I can push over that rock at lower rpms.

So, why would I want to do it at lower rpms? *



* Every 4 x 4 forum prefers diesel engines because they have more torque.
.
 

TA1ton

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@Joe98; simple answer to why low end torque is better for off-roading is it offers better control of the vehicle. Using higher rpms to climb over an obstacle translates to a faster wheel speed which makes maneuvering very jerky.
 

TA1ton

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@Joe98; no problem! Happy Jeeping! :like::jk:
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