kriz

Sorry if this seems like a dumb question but I've never quite understood how the two relate to racing/overall car performance. I mean, I've read tons of articles on the difference between horse power & torque. Correct me if I'm wrong but hp is essentially the amount of raw power the engine can output while torque is the engine's ability to turn that power into rotary force thus spinning the wheels. Or at least something along those lines.

In any case, my question is how does hp and torque affect your car's performance? Will an engine with higher torque than hp perform better?

EDIT: Just realized this isn't really a racing or driving "technique," but it does relate to driving/racing. Sorry if this is the wrong area for this post its early in the morning my brain doesn't come on until 10a

Crx Kid22

horse power is just an equation its torque=5252xhorsepower/rpms
you can offset your hp greatly by maxing out rpms thats why every other country uses kilowatts hope this helps

Crx Kid22

how do you edit?

awptickes

As CRX kid said, HP is attained through the assistance of gearing. Power output is what really matters, kW ftw.

__________________
☻/ DIY/Howto HID Projector retrofit
/▌
/ \

kriz

So... more torque >> more hp??

Oh and Crx Kid you can edit after you become a junior member, there's an "edit" button on your posts

K2e2vin

o_0

HP=Power, kW=Power; they're just different measurements(1hp=746W).

Torque is what can be had through gearing. HP stays the same. When you build your motor, you're looking to increase torque across a desired power band. More HP=faster car as it's an equation of how fast the vehicle will move over time.

What people fail to realize, any time you're gaining torque, HP is also going up. Do not confuse this with peak HP. You can increase torque in the mid rpm band, and have no increase in peak HP, but the HP in the mid band will go up.

__________________
1988 Honda Civic Standard-more mods than I want to list
1992 Honda Accord LX
1996 Toyota Avalon-Spun bearing, for sale.

Terrorists have successfully attacked our imagination.

RIP
Jon Eban Nie, August 31, 1991 - May 7, 2006
Y-Daniel Siu Eban, September 7, 1986 - May 7, 2006

Crx Kid22

horspower is a measure of tourque... and rpms

K2e2vin

And the definition of horsepower is???

....???

550ft-lb per second. This was derived from horses being able to pull 550lbs of weight one foot in one second. It's a measure of work.

Yes, it's derived from tq*rpm/5252, but it also means something. They didn't just randomly make up an equation.

__________________
1988 Honda Civic Standard-more mods than I want to list
1992 Honda Accord LX
1996 Toyota Avalon-Spun bearing, for sale.

Terrorists have successfully attacked our imagination.

RIP
Jon Eban Nie, August 31, 1991 - May 7, 2006
Y-Daniel Siu Eban, September 7, 1986 - May 7, 2006

B

at the end of the day, its the total area (limits in calculus) under the torque curve for all rpms, and taken into consideration each gear's rpm drop and pull...

tons of math... heh

hp and torque lines always cross at 5252. thus, diesels (and other low rpm motors) that redline before 5252 will NEVER have more horsepower than torque.

the ideal power car is based off gearing and horsepower AND torque.
a shift at horsepower peak that lands on torque peak through all 4-5 shifts (5 or 6 speeds) is the most effect use of the power band.

__________________

Calesta

Back to basics.

Torque is a measure of force.
Horsepower is a measure of power.

Look at the metric unit measures. Torque is measured in Newton-meters. Look up the specs for any car outside the US- you'll see torque listed as "N-m".

Power is a measure of the application of force over time. Metric power = watts = newton-meters per second, or N-m/s.

Breakdown:

force = 1 N-m
power = 1 W = 1 N-m/s

Torque is your measure of raw pushing ability. That's why you see all the larger engines having higher torque numbers than smaller engines. They generate more force. As rpms rise, power goes up because you're able to apply that force more often in the same period of time. If your torque output on the dyno looks like a flat line, your power output measure will be a perfect slanted line rising with engine speed.

Power is what ultimately gives you the measure of how much work can be performed in a period of time. The more power you have, the more potential you have for faster acceleration. Because of the previous explained relationship between torque and power, you can now understand that you can have the same power output with vastly different torque outputs. A small 4 cylinder engine with half the torque output of a larger V8 can still make the same amount of power- it just has to spin twice as fast.

So remember...

Torque = force
Power = application of force over time = measure of ability to perform work

__________________
DO NOT PM me with tech questions! Use the forums!
Intercrew Auto Salon - (972) 485-8688

awptickes

SO YOU'RE SAYING VTECH SHOULED BE SET TO 5252???






buhahahahahahahahahaha. I'm gonna watch this seed grow into a tree now.

__________________
☻/ DIY/Howto HID Projector retrofit
/▌
/ \

TurboRex90

You cant increase horsepower if you cant increase torque. At least that's what i know what dyno run experiences.


BAHAHA!

__________________
Boost is not a hobby, It's pure addiction.

Wanna check out my build progress?
http://www.cardomain.com/ride/3029308

Crx Kid22

yes you can if you look at the equation rpms is in it so if you have low torque and high rpms you could have the same hp. think of motorcycles ever seen a 2cycle engine? ever seen a 4cycle engine? well they can both have the same hp because they both have a part in the equation!

__________________
have you seen that house guy? hes mean

dcasey12

Basically any engine will have a limited amount of torque depending on how much air and fuel is squeezed into it. So an efficient 3 litre car engine can produce similar torque (theoretically) to a formula 1 , 3 litre engine. Where the difference lies is when the torque is produced, a normal car engine will do it between 2000rpm and 6000rpm, a formula 1 engine does it at 13000 to 18000 rpm. As horsepower is a product of RPM and torque thats how the extra power is gained. An engine produces X amount of force (torque) 4000 times(rpm) per minute and the formula 1 engine produce X amount of torque 15000 times per minute.
Just remember High horse power isnt everything, If your car only produces power over a 2000rpm range and you dont have a close ratio gearbox to suit you will be sitting around twiddling your thumbs waiting for the power to come on everytime you change gear.

TurboRex90

I dont know, at the dyno when my torque line started to drop because of valve float my HP came to a stop and woulnt get any higher. But maybe your right.

__________________
Boost is not a hobby, It's pure addiction.

Wanna check out my build progress?
http://www.cardomain.com/ride/3029308

eg'sforlife

basically torque is used to accelerate and horsepower is used to hold that speed

AHHVTEC

that ^^ hp takes over for torque after you get going good

kriz

Ah I see, that makes a lot of sense. Thanks a lot for the explanations guys, you're all very helpful.

K2e2vin

Torque is the twisting force and horsepower is that twisting force multiplied by how fast it's moving.

It's better to look at trucks; more torque=haul more while more hp=able to move faster.

__________________
1988 Honda Civic Standard-more mods than I want to list
1992 Honda Accord LX
1996 Toyota Avalon-Spun bearing, for sale.

Terrorists have successfully attacked our imagination.

RIP
Jon Eban Nie, August 31, 1991 - May 7, 2006
Y-Daniel Siu Eban, September 7, 1986 - May 7, 2006

awptickes

Someone told me once:

__________________
☻/ DIY/Howto HID Projector retrofit
/▌
/ \

E_SolSi

__________________

МОΛΏΝ ΛΑΒΈ

kriz

lol thanks, that explains everything