Jump to content
IGNORED

Finding/defining/debating the difference between Torque and Horsepower..


cowpuc

Recommended Posts

Torque is a measure of force. Power is a measure of work - the rate at which a mass is moved over a distance, basically. How often (RPM - applications of force per unit of time) a force (torque) is applied to a mass, defines how much power has been produced, if the unit of distance is considered constant, and therefore disregarded.

 

My dad used to say that people buy horsepower, but drive torque.

 

Both are important. A fantastic example of this is the 'diesel wars' between Ford, GM and Dodge. The magazines test how the trucks accelerate a loaded trailer, and how long it takes them to make it up a long steep hill pulling it. Inevitably, the one with the most torque wins the accelleration test, but the one with the biggest power number wins the hill climb.

 

Until you start breaking driveline parts, there is no such thing as too much of either. Only enough, not enough, or more than enough!

 

I wanted to add to this: a big V-twin feels a lot like a diesel V8, while a higher revving V4 feels more like a performance gas V8.

 

When I was a young hooligan, I sometimes drove my dad's '72 Ford with a 351 Cleveland 4V-HO motor. It wouldn't lift the front wheels off the ground like some of the big blocks I tried out, but man did it perform between 4-7000rpm.

 

At the time, my car was a Mazda RX7. It worked like an inline-4 sportbike. Gutless on the low end (i.e. no torque), but would start to spin the tires at around 8500rpm (good horsepower, once you had the revs up to where the math was working in your favor.)

 

In terms of heavy-weight motorcycles, the choice is whether you want to live in the low end, or the mid-range of the bike's RPM. These aren't sportbikes, and I don't think anyone is running the motor at 9/10ths, tap dancing on the shifter.

Edited by SilveradoCA
Link to comment
Share on other sites

Boy I have a lot I really want to say about you cowpuc, but I will just bite my lip and not engage you because in the end your just not worth it.

 

 

You need to get a thicker skin. CowPuc would be the first to ride 300 miles to help you out. He is also so much fun to be around. If you leave ypu will be missing out on some of the greatest people that ride. I for one have mad so many friends on here that will be lifetime friends. In fact there are so many that i could probably go on a 30 day ride and not need to get but a couple of nights in a motel. You will not find friends like that just anywhere. Cowpucs opinion is just that his opinion. You probably have an opinion on the 1st gen and 2nd gen that doesn't mean any of the bikes are bad. Remember people on here are attached to the water cooled v-4. I for one believe they made a mistake with the V Twin but i don't think the bike is a bad purchase. Stick around and learn about the people onthis sight. you will not find a better bunch of Bikers.

Again Just My Opinion

Link to comment
Share on other sites

I didn't see this called out (I only skimmed the thread, didn't watch the videos, cuz I'm lazy), but here is an equation everyone should know:

 

HP = Torque x RPM ÷ 5252

 

Reference here:

 

http://www.epi-eng.com/piston_engine_technology/power_and_torque.htm

 

Now, that being said, horsepower is just a function of torque and RPM. So the more torque you make higher in the RPM band, the more peak horsepower the engine will make. This is just math.

 

Thing is, torque in the low part of the RPM band is what gets you going from a standing start. What matters is a broad torque curve, knowing what your torque curve is and using it skillfully as you accelerate.

 

In day-to-day use, high peak horsepower way up in the RPM band is really useless. (Unless ALL your torque is up there, then you just have a high-revving engine, shift accordingly, etc etc etc).

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...