Horsepower vs. Torque?

[01mgvert]

Help me to understand the difference between horsepower and torque. It seems to me that torque is what moves the car from a dead stop and horsepower is what keeps it accelerating.

A stock Mustang makes 260 bhp and 302 ft/lbs torque. With my current mods, my car dynoed at 250 rwhp and 290 ft/lbs torque. With an automatic transmission, that equals 310 bhp and 360 ft/lbs torque. A stock 2002 Firebird, with the 5.7l LS1, makes 310 bhp and 340 ft./lbs torque. What advantage do I have with 20 ft/lbs of additional torque?

 

[crew_dawg16]

torque is a twisting or rotational force. This is the ability for your engine to get your car moving. Horsepower is a byproduct of Torque and RPM. They usually intersect on a dyno sheet at around 5250 rpms.

 

[crew_dawg16]

you have the advantage of getting them off the line with traction, however, once the horsepower comes into play (3rd gear) the ls1 will reel you in if you don't have any mods.

You don't have that much torque though, your first gear is better than an ls1

 

[XtorT'r]

TORQUE!!

Damn, I thought this was gonna be a " tastes great", "less filling" thread...

I didn't know that the Auto tranny sapped that much power.. Everything I ever see About the LS1's is that they actually made 350bhp and they were rated lower for insurance reasons or something like that. I also hear that the 03+ cobras make more like 420bhp and are rated lower for the same reason. So if your starting to think that your equil to an LS1.. you have a long way to go.. Sry

 

[trinity_gt]

Help me to understand the difference between horsepower and torque. It seems to me that torque is what moves the car from a dead stop and horsepower is what keeps it accelerating.

Torque is a twisting force. HP is a measure of the rate at which work is done. Work, in turn, is the moving of a mass through a distance. Torque applies to the "instant"; it provides the "instantaneous acceleration", the oomph you feel in the back when accelerating. Power becomes more and more dominant as when longer time periods are considered. A top-speed run at Bonneville, a drawn out affair, for instance, is more dependant on horsepower than on absolute torque. Contrast this to a loaded big-rig pulling away from a stop light; fifty thousand pounds of mass to move requires a ton of torque. The fact that it takes forever to reach speed shows a comparative lack of HP, the fact that it moves at all is a sign of great torque.

Your conclusion is pretty much right I think.

 

[GDawg]

Torque is a twisting force. HP is a measure of the rate at which work is done. Work, in turn, is the moving of a mass through a distance. Torque applies to the "instant"; it provides the "instantaneous acceleration", the oomph you feel in the back when accelerating. Power becomes more and more dominant as when longer time periods are considered. A top-speed run at Bonneville, a drawn out affair, for instance, is more dependant on horsepower than on absolute torque. Contrast this to a loaded big-rig pulling away from a stop light; fifty thousand pounds of mass to move requires a ton of torque. The fact that it takes forever to reach speed shows a comparative lack of HP, the fact that it moves at all is a sign of great torque.

Your conclusion is pretty much right I think.

Good explanation... I've always had a hard time "visualizing" this concept even though I'm fairly good at physics.

An example: S2000 - 240 hp and 163 ft/lbs of torque... My '98 GT has 225 hp and 290 ft/lbs of torque. S2000 - 600 lbs lighter.... I took one with an equal driver (could bang his gears with best of them, me included). We started from a 20mph roll, him one car length ahead, I caught him, pulled on him and passed him (one car length) up to 80mph before we came into dense traffic. My beast is just that for a Slowstang.... 3.73 coming in 14 days....

 

[V_Eight]

"HP sells the car, Torque moves it."

 

[01mgvert]

Damn, I thought this was gonna be a " tastes great", "less filling" thread...

I didn't know that the Auto tranny sapped that much power.. Everything I ever see About the LS1's is that they actually made 350bhp and they were rated lower for insurance reasons or something like that. I also hear that the 03+ cobras make more like 420bhp and are rated lower for the same reason. So if your starting to think that your equil to an LS1.. you have a long way to go.. Sry

I guess that I am not convinced that I have a long way to go. The stock 2002 Firebird has 310 bhp and 340 ft/lbs torque and weighs 3341 lbs. My modded Mustang has 310 bhp and 360 ft/lbs torque and weighs 3429 lbs. Even if the horsepower is underrated for the Firebird, it still runs 5.1 seconds from 0-60 mph. With my mods and 4.10s, I am able to match that time. My point is this: It is no longer a one-sided race; I have a chance of winning or at least staying even (provided the Firebird is stock).

 

[trinity_gt]

Good explanation... I've always had a hard time "visualizing" this concept even though I'm fairly good at physics.

Thank you.

.. 3.73 coming in 14 days....

Interesting thought exercise: Given that power at the wheels is what matters in extended runs, not torque, those gears probably won't help as you leg it up to 80MPH against S2000s. You might get an initial, "instantaneous" jump, bigger than before, but with the same ultimate power at the wheels don't expect things to change drastically in when hoofin' it to higher speeds over longer periods of time.

 

[Silver2003Cobra]

torque is a twisting or rotational force. This is the ability for your engine to get your car moving. Horsepower is a byproduct of Torque and RPM. They usually intersect on a dyno sheet at around 5250 rpms.

since HP is a measurement taken from RPM and Torque, it will ALWAYS cross on a dyno at 5250 rpm..

 

[Silver2003Cobra]

Good explanation... I've always had a hard time "visualizing" this concept even though I'm fairly good at physics.

An example: S2000 - 240 hp and 163 ft/lbs of torque... My '98 GT has 225 hp and 290 ft/lbs of torque. S2000 - 600 lbs lighter.... I took one with an equal driver (could bang his gears with best of them, me included). We started from a 20mph roll, him one car length ahead, I caught him, pulled on him and passed him (one car length) up to 80mph before we came into dense traffic. My beast is just that for a Slowstang.... 3.73 coming in 14 days....

hmmmmm, yes the S2000 has less torque than any Modular V8 Mustang at the flywheel, but where it counts it does have more(at the rear wheels) since the tranny and rearend gearing convert the F20C1's low torque and high rpm into high torque and low rpm..

I also don't see any 96-98 GT, especally a ragtop pulling on any S2000. I had a 97 Cobra coupe and in a race with a S2000 I'd call them dead even, drivers being equal, and your saying that your 225 hp ragtop GT not only caught a S2000 but pulled on one????

 

[FallenPhoenix]

I guess that I am not convinced that I have a long way to go. The stock 2002 Firebird has 310 bhp and 340 ft/lbs torque and weighs 3341 lbs. My modded Mustang has 310 bhp and 360 ft/lbs torque and weighs 3429 lbs. Even if the horsepower is underrated for the Firebird, it still runs 5.1 seconds from 0-60 mph. With my mods and 4.10s, I am able to match that time. My point is this: It is no longer a one-sided race; I have a chance of winning or at least staying even (provided the Firebird is stock).

The problem is the f-bodies were underrated, not due to insurance but because there is a policy within GM that no GM passenger car can have more horsepower than the almighty vette. Also, most f-bodies weigh closer to 3600lbs, 3341 is probably with manual windows, manual tranny, etc. I'd say you could take an LS1 if you can drive equal or better to the LS1 driver.

 

[trinity_gt]

hmmmmm, yes the S2000 has less torque than any Modular V8 Mustang at the flywheel, but where it counts it does have more(at the rear wheels) since the tranny and rearend gearing convert the F20C1's low torque and high rpm into high torque and low rpm..

Let's check:

http://www.new-cars.com/2004/honda/honda-s2000-specs.html

S2000:
1 3.133
2 2.045
3 1.481
4 1.161
5 0.942
6 0.763
Axle: 4.10
Engine torque: 162 ft-lbs

http://www.new-cars.com/2002/ford/ford-mustang-specifications.html

2002 Ford Mustang:
1 3.37
2 1.99
3 1.33
4 1.00
5 0.67
Axle: 3.27
Engine torque: 302 ft-lbs

1st gear:
S2000: 162*3.133*4.10 = 2081 ft-lbs at the hubs, ignoring losses
MGT: 302*3.37*3.27 = 3094 ft-lbs

2nd gear:
S2000: 162*2.045*4.10 = 1358 ft-lbs at the hubs
MGT: 302*1.99*3.27 = 1965 ft-lbs

3rd gear:
S2000: 162*1.481*4.10 = 984 ft-lbs at the hubs
MGT: 302*1.33*3.27 = 1313 ft-lbs

4th gear:
S2000: 162*1.161*4.10 = 771 ft-lbs at the hubs
MGT: 302*1.00*3.27 = 987 ft-lbs

5th gear:
S2000: 162*0.942*4.10 = 626 ft-lbs at the hubs
MGT: 302*0.67*3.27 = 662 ft-lbs

6th gear:
S2000: 162*0.763*4.10 = 507 ft-lbs at the hubs
MGT: 302*0.67*3.27 = 662 ft-lbs (5th used)

The gearing on the S2000 doesn't produce more rear wheel torque in any gear than the MGT. The gearing is simply well matched to the RPM abilities of the engine. Power to the wheels is what's important in long, drawn-out pulls.

That the S2000 weighs 2835 lbs at the curb versus the MGTs portly 3200+ makes a big difference...

 

[GDawg]

hmmmmm, yes the S2000 has less torque than any Modular V8 Mustang at the flywheel, but where it counts it does have more(at the rear wheels) since the tranny and rearend gearing convert the F20C1's low torque and high rpm into high torque and low rpm..

I also don't see any 96-98 GT, especally a ragtop pulling on any S2000. I had a 97 Cobra coupe and in a race with a S2000 I'd call them dead even, drivers being equal, and your saying that your 225 hp ragtop GT not only caught a S2000 but pulled on one????

Ha ha ha... I love guys like you. I was toyed with for ~5 miles before I decide to take him. I wish I had the link to my thread explaining the details as I don't feel like typing a book again. It's on this board so do a search.

Everything I said was real, true, accurate and factual. While I was screaming my engine I could hear his engine (we were both rag tops) and I thought he was going to explode any minute. Maybe my 3.27 had something to do with it... maybe he had a buffalo in his trunk... Don't think a '98 is a '96 - '97. There is a 10 hp difference and a 3.27 option that I happen to have. I'm not saying that that is the reason I embarrased him but I definitely out drove him with my 17 year old daugher in the car to laugh all the while. I'm 46 years old... this is not a fantasy story to impress you.

Believe it or not... I was there, did it and don't fear anyone whether I am certain to lose or not.

 

[wms004]

Help me to understand the difference between horsepower and torque. It seems to me that torque is what moves the car from a dead stop and horsepower is what keeps it accelerating.

A stock Mustang makes 260 bhp and 302 ft/lbs torque. With my current mods, my car dynoed at 250 rwhp and 290 ft/lbs torque. With an automatic transmission, that equals 310 bhp and 360 ft/lbs torque. A stock 2002 Firebird, with the 5.7l LS1, makes 310 bhp and 340 ft./lbs torque. What advantage do I have with 20 ft/lbs of additional torque?

Hate to tell you, but the LS1's dyno at 300-310 to the wheels. Unless you are running DR's and an LS1 isn't, no N/A gt stands a chance.

 

[01mgvert]

The problem is the f-bodies were underrated, not due to insurance but because there is a policy within GM that no GM passenger car can have more horsepower than the almighty vette. Also, most f-bodies weigh closer to 3600lbs, 3341 is probably with manual windows, manual tranny, etc. I'd say you could take an LS1 if you can drive equal or better to the LS1 driver.

Thanks for the encouragement. I got beat pretty bad last summer by a Camaro SS. Even though I am no longer stock, I have been reluctant to race a Camaro or Firebird. When I look at the numbers, it appears that I now at least have a chance.

 

[FallenPhoenix]

Well if you still get beat, at least you're doing it in style with the top down

 

[XtorT'r]

I guess that I am not convinced that I have a long way to go. The stock 2002 Firebird has 310 bhp and 340 ft/lbs torque and weighs 3341 lbs. My modded Mustang has 310 bhp and 360 ft/lbs torque and weighs 3429 lbs. Even if the horsepower is underrated for the Firebird, it still runs 5.1 seconds from 0-60 mph. With my mods and 4.10s, I am able to match that time. My point is this: It is no longer a one-sided race; I have a chance of winning or at least staying even (provided the Firebird is stock).

like it is said you can keep up, maybe even pull on him but your not gonna even kinda keep up in third. and who cares wht you have BHP you only have 250rwhp your not keepin up with 310rwhp when you start to roll down the track, your only hope from here if your gonna keep that HP is to get better shift points, 4.10's, much better suspension system, and go on a diet. and no one races 0-60 at the track.. at least not what I have seen.

 

[00s281sc368]

The formula is simple:
HP=Torque x RPM.

Twice more torque will give you twice more HP at the same rpm.

Trinity_GT's post is very good for torque-at-the-wheels comparaison, but it's also based on the max torque. A GT torque curve is quite flat compared to a S2000, and it's peak is at ~3000rpm, but the S2000 is more like 6000rpm. At 3000rpm the S2000 still has nothing

 

[dmarco_4u]

Well if you still get beat, at least you're doing it in style with the top down