Horsepower vs. torque

[Justin Kirkham]

Hey there, searched and couldn't find it. Below are two types of cars.

1. Cars with higher torque and lower horsepower. ((Say 300 torque and 200 horsepower))Example: GT Mustang

2. Cars with lower torque and higher horsepower.
((Say 200 torque and 300 horsepower)) Example: Acura RSX Type S

3. Cars with equal horsepower and torque.
((Say 250 horsepower and 250 torque)) Example: Mistubishi GT

Could someone give me a quick idea of how these cars would fare against each other, all other things being equal? Just a point of curiosity for me.. What I mean is, will a far with high torque and low HP beat a car with low torque high HP, etc.

-DrkMind11

[rob231]

i think you need those engines in the same car. weight differences between those cars could make them equal. also at what rpm's and gear ratio's would x engine make y power. you know what i'm saying?

[ravenp]

HP is a factor of torque times rpm divided by a number i forget [img]smile.gif[/img] (anyone?)

Anyways, car x that makes 150hp at 3500rpm, with 245lbs-ft torque at 4000rpm(an 84 z28, 305), could hang with a car y that makes 200hp at 5200rmp and 225lbs-ft torque at 4000(97 camaro).

....but there are other factors as rob231 mentioned. for example, the above 2 cars... the 84 is a 5 speed with 3.23 gears...and the 97 is an auto with 3.08's. The gears and tranny of the lower hp rated car will bring it up to the 97 in the 1/4 mile because of it's lower torque band, higher gears, and manual tranny. basically it gets its' power to the ground faster...and gets to it's peak torque band quicker. so unless traction is a problem, those factors make up for the 50hp(at least in the case of my fiance's 84 and my 97)

so your question is hard to answer. the rice rockets have higher hp than torque because of that formula I mentioned...their power band is up in the 6000rpm range and higher sometimes. that's how their hp ratings are high.. in the 1/4 mile time this usually will translate into slow 60' times, but high trap speeds.

other factors that make your question dificult to answer are weight of the car, ability of the driver...heat and humidity(affects bigger engines more), traction and what type of race.

the three cars you give as examples. i dont' know that i agree with the listed numbers, but accepting them as true, i'd give the edge to the mustang, provided it has high gears and great tires. if you're talking 1/4 mile. if it's a highway race, i'd give it to the acura hands down.

hope this helps (not confuses too much [img]smile.gif[/img]

[GregWS6'01]

This is what you want


http://www.vettenet.org/torquehp.html

[Dominic]

Torque is always equal to horsepower at 5252rpm - its mathematically impossible for that to be untrue.

Torque is sheer force, horsepower is force per a given time. With ideal gearing the engine making the most horsepower always wins - 200hp @ 3000RPM is the same as 200hp @ 18,000RPM, and they both accelerate equally.

Since gears are driven through accelerating RPMs though, and are not always at peak horsepower, the engine with the most torque across the band usually wins - given the gearing is the same for both cars.

It all comes down to (gearing being identical and weight of the vehicle being identical) the area under the horsepower curve. The slope of the horsepower curve or the flatness of the torque curve will tell you how strong an engine is... you'll note the larger displacement engines usually end up beating out the smaller displacement engines in the torque catagory almost everytime, and with proper gearing they can win races too [img]smile.gif[/img] Well - drag races.

[ravenp]

wow...great explanation... i knew i was close [img]smile.gif[/img]

[Paul Collins]

horsepower is a mathmatical number that until the right before WWI(I think) had never been thought of before. When a gentleman (name escapes me) watched a horse walking in s circle that pulled a rope that raised some bricks. Being a mathmatician he calculated horse power. by using the weight of the bricks(weight of our car), the pully ratio(transmission), how long it took to raise the bricks(time) and the lengthof the shaft the horse was attached to(torque). [img]graemlins/burnout.gif[/img]

So in reality horsepower is a fictional number anddoesnt matter :D :D :D

And if anyone believes that I have some swamp land out in west texas to sell ya.

[Paul Collins]

oh damn i just read that vettenet thing
dont i look stupid now.

anyway i was just making a joke work is being too stresfull.

[hawgs]

horsepower sells cars, torque wins races :D

[HAZ-Matt]

The unit "horsepower" was invented by the man who gave us the steam engine, James Watt.

From Howstuffworks:
<blockquote>quote:</font><hr>The story goes that Watt was working with ponies lifting coal at a coal mine, and he wanted a way to talk about the power available from one of these animals. He found that, on average, a mine pony could do 22,000 foot-pounds of work in a minute. He then increased that number by 50 percent and pegged the measurement of horsepower at 33,000 foot-pounds of work in one minute.<hr></blockquote>
It doesn't say why he increased it by fifty percent... but I can tell you why. In order to sell his steam engines, he wanted a unit that would sound more reasonable to the consumers, so he "overrated" horsepower to effectively "underrate" his steam engines. That bit of info came from my physics book (Physics for Scientists and Engineers, Giancoli)

[ September 03, 2002: Message edited by: HAZ-Matt ]</p>

[Silver3800V6FBodyKY]

<blockquote>quote:</font><hr>Originally posted by Dominic:
Torque is always equal to horsepower at 5252rpm - its mathematically impossible for that to be untrue.<hr></blockquote>

---Ahhh, Derivatives

<blockquote>quote:</font><hr>Originally posted by Dominic:
Torque is sheer force, horsepower is force per a given time.<hr></blockquote>

Almost... Torque is sheer force multiplied by a distance. (Work=Force x Distance, Work=Torque)

[ September 03, 2002: Message edited by: Silver3800V6FBodyKY ]</p>

[Dominic]

<blockquote>quote:</font><hr>Originally posted by Silver3800V6FBodyKY:


Almost... Torque is sheer force multiplied by a distance. (Work=Force x Distance, Work=Torque)

[ September 03, 2002: Message edited by: Silver3800V6FBodyKY ]<hr></blockquote>

Torque is not work, torque is a rotational force. Have you not taken physics young lad? [img]graemlins/omg.gif[/img]

[Silver3800V6FBodyKY]

<blockquote>quote:</font><hr>Originally posted by Dominic:


Torque is not work, torque is a rotational force. Have you not taken physics young lad? [img]graemlins/omg.gif[/img] <hr></blockquote>

Torque is work.

Work=Force x Distance
Torque= Force x Distance

Substitution: Work=Torque

Torque is not always rotational. If you move 10lbs. 5 feet, then the torque you applied to the 10lbs object to get it to move 5 feet is 50lbs.ft.

Also the work you did was 50lbs.ft.

Rotational or not, both are measured in force x distance.

[12secondv6]

Torque makes me pull a tire off the ground
Torque makes me pull 1.63 60 foot times
Horsepower makes me trap 107.5 mph

[AZ3.8Camaro]

In all reality it all comes down to this. My car = 200HP and 212? TQ. 11 Second Nitrous Nova = A ton of HP and TQ and finally solving for x and round off we get car with more nitrous beats car with no nitrous. Basically, you never know until you race.