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Discussion Starter · #1 ·
I know this thread has been posted before and i kinda got an idea what torque is being that you feel and what gets you off the line. But with all these superchargers and turbos out what really makes the difference? Lets say you have higher HP than torque like most the 3.5 superchargers produce? Or higher torque than HP? What will you notice in both situations? Why is HP even important? Thanks
 

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Really a question?

You do understand what HP is, correct?
 

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Discussion Starter · #3 ·
Not really man i just know i just drive cars. Im just trying to learn.
 

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Discussion Starter · #5 ·
Man forgive me but i have no clue what that means. Im just wanting to know the difference in driving a car with a higher HP with lower torque vs. driving a car with higher torque and lower hp. Like if a car has 350 HP with 370tq or 323hp with 280tq.
 

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Torque gets you moving, hp makes you move faster
 

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Discussion Starter · #7 ·
Cool so lets say something wild like i had 500 hp with only 250tq would that mean it would take longer to get going? lol Then eventually getting fast?
 

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Cool so lets say something wild like i had 500 hp with only 250tq would that mean it would take longer to get going? lol Then eventually getting fast?
Kinda.

Look at the 9000-RPM Honda S2000 .... 240 hp but only 160 ft-lbs of torque makes for slow getaways, but once moving, as long as the RPMs are kept up there, there's no lack of motivational force :)
 

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Discussion Starter · #9 ·
Aw ok now it makes sense. Sorry i know it makes everyone mad when these type of threads are posted. I just wish i knew more about cars besides wanting them to be fast but not knowing the basics of an engine. Maybe in my next life lol
 

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Sorry i know it makes everyone mad when these type of threads are posted.
No worries, we were all newbies at one time :) And your question, while a seemingly simple question, to truly understand the relationship, is complex.
 

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Torque is what gets you moving off the line...horsepower is what keeps you moving, in simple terms. Yes, there is always torque present, just in varying amounts.

Compare to getting a nut or a bolt to loosen, it requires torque on your part to "free" it but once it has been turned, it no longer requires the same amount of torque...simply turning it off the rest of the way is, in a simple way, what horsepower is. Very simple terms... does that make sense?

Horsepower is a product of torque.
 

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As an automotive engineer, I've thought of different ways to explain this, but here's the best way I've found:

Torque is how HARD the engine is turning
RPM is how FAST the engine is turning
Horsepower is nothing more than the product of the two


In other words, an engine spinning twice as fast and half as hard is making the same power as an engine spinning half as fast and twice as hard. Thus, you can get a 2.0L four cylinder in a Honda S2000 to make 240 hp, the same as your average 3.5-4.0L V6, because it produces it's torque so FAST.

Torque and horsepower are related, but are different entities. You can't say an engine has "more torque than horsepower". That would be like saying you had more height than money. The number of one might be higher than the other, but that depends on the units: lb-ft or Nm, hp or kW.

If torque was constant (say, 300 lb-ft), acceleration would be constant in any given gear, but horsepower would be climbing with RPM (100, 200, 300, etc). Torque is what you actually feel, horsepower is a way to take into account the speed it's being delivered at. So, a 300 lb-ft car with 150 hp would accelerate at the same rate in the same gear as an identical car with 300 lb-ft and 300 hp, but for only half as long. The 300hp car would destroy it because it can keep up that given acceleration for twice as long.

Sorry for the windy post, but maybe this helps! My senior design project was a dynamometer, so this is close to my heart.
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As an automotive engineer, I've thought of different ways to explain this, but here's the best way I've found:

Torque is how HARD the engine is turning
RPM is how FAST the engine is turning
Horsepower is nothing more than the product of the two


In other words, an engine spinning twice as fast and half as hard is making the same power as an engine spinning half as fast and twice as hard. Thus, you can get a 2.0L four cylinder in a Honda S2000 to make 240 hp, the same as your average 3.5-4.0L V6, because it produces it's torque so FAST.

Torque and horsepower are related, but are different entities. You can't say an engine has "more torque than horsepower". That would be like saying you had more height than money. The number of one might be higher than the other, but that depends on the units: lb-ft or Nm, hp or kW.

If torque was constant (say, 300 lb-ft), acceleration would be constant in any given gear, but horsepower would be climbing with RPM (100, 200, 300, etc). Torque is what you actually feel, horsepower is a way to take into account the speed it's being delivered at. So, a 300 lb-ft car with 150 hp would accelerate at the same rate in the same gear as an identical car with 300 lb-ft and 300 hp, but for only half as long. The 300hp car would destroy it because it can keep up that given acceleration for twice as long.

Sorry for the windy post, but maybe this helps! My senior design project was a dynamometer, so this is close to my heart.
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Nice explination
 

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Discussion Starter · #17 ·
I get confused at lbs..As much as i watch horsepower tv i should know this crap.
 

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Discussion Starter · #18 ·
Torque is what gets you moving off the line...horsepower is what keeps you moving, in simple terms. Yes, there is always torque present, just in varying amounts.

Compare to getting a nut or a bolt to loosen, it requires torque on your part to "free" it but once it has been turned, it no longer requires the same amount of torque...simply turning it off the rest of the way is, in a simple way, what horsepower is. Very simple terms... does that make sense?

Horsepower is a product of torque.

That really makes alot of sense. I was wondering all this crap guys because i wanted to know since the supercharger for the v6 makes less torque than a hemi how would that pan out in a race? Would the higher hp make me catch up in the higher rpms. or would his torque still out run me?
 

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That really makes alot of sense. I was wondering all this crap guys because i wanted to know since the supercharger for the v6 makes less torque than a hemi how would that pan out in a race? Would the higher hp make me catch up in the higher rpms. or would his torque still out run me?
all things equal, lower torque car would lose the race
same torque, higher hp, depends on how fast you take the race

Lot of variables, including minor things like our hemi's hate hot weather.
 

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All things truly equal; vehicle, torque, weather, conditions, driver, etc, the higher hp car will always win.


Remember, you can trade RPM for torque and vice-versa with gearing, but HORSEPOWER IS FIXED. In other words, if car A has 400 hp and 300 lb-ft of torque, it will beat an identical sized car B with 300 hp and 300 lb-ft of torque in one of two ways:

Car A can have the same gear ratio as Car B. In this case, they will initially accelerate at the same rate, but Car A will be able to keep it up longer while Car B has to shift to a higher gear since it runs out of RPM. Car A will pull away.

Car A can have more gear ratio, making the torque at the tires greater than Car B but maintain it up to the same speed. It will accelerate faster right off the bat, and shift at the same speed.

So you can get a tiny 4 cylinder to make 400 hp, but it will have to rev very high and be geared very low, and that makes for a BAD driving experience (noisy, jumpy, bad gas mileage, etc). Having good low-end torque is MUCH more fun and usable. If it can ALSO keep it up into higher revs, you have a great engine. Long live the HEMI.
 
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