Simple explaination of HP vs Torque, using an FRS as an example..

[BRZnut]

Video near the end uses the FRS as an example of a car with a dip in torque mid-RPM, making the car feel "gutless". I know others have noticed this but I haven't. Will need to pay attention more.


http://cnettv.cnet.com/car-tech-101-...-50141789.html

[Snozzberries]

Originally Posted by BRZnut

Video near the end uses the FRS as an example of a car with a dip in torque mid-RPM, making the car feel "gutless". I know others have noticed this but I haven't. Will need to pay attention more.


http://cnettv.cnet.com/car-tech-101-...-50141789.html

I definitely notice the torque dip depending on my clutch play. If I am driving super easy, I don't usually see it. If I am dumping at 3k, I don't usually see it.

[SloS13]

Horsepower - how fast you hit the wall. Torque is how far you take the wall with you.

[BRZnut]

Originally Posted by Snozzberries

I definitely notice the torque dip depending on my clutch play. If I am driving super easy, I don't usually see it. If I am dumping at 3k, I don't usually see it.

It shows the Torque takes a dump at 4K RPM. I'll have to see if I notice it

[akuhei]

I definitely notice...its like the car slows between 3.5-4.5k wish..before picking back up and pulling again. The tune helped..but its still there and bothers me a little...

[Rayme]

Nothing new as far as a NA 4 cylinder. You drive it with the engine over 5000 RPM if you want results.

I personally love that early torque, works well in town.

[BRZnut]

Have to agree..the early torque adds a great deal of pep around town.

[fatoni]

Originally Posted by ottopilot

Nothing new as far as a NA 4 cylinder. You drive it with the engine over 5000 RPM if you want results.

I personally love that early torque, works well in town.

calm down, this is the internet. we wont have your sense here. we want to drive a slow car slowly and complain about how it not being fast.

[switchlanez]

Originally Posted by ottopilot

Nothing new as far as a NA 4 cylinder. You drive it with the engine over 5000 RPM if you want results.

I personally love that early torque, works well in town.

Yeah, that's the way to look at it. People tend to complain about the torque dip when we should instead be grateful for the 2 peaks gifted to us.

[rice_classic]

While accurate, it was too fast and poorly presented. He glanced over the most important difference between the two in a matter of seconds.

[dnL]

I only watched the vid because an FR-S is in it.

[Hawaiian]

Originally Posted by switchlanez

Yeah, that's the way to look at it. People tend to complain about the torque dip when we should instead be grateful for the 2 peaks gifted to us.

After all... who dosen't like 2 peaks

[switchlanez]

I can try to explain the horsepower/torque relation using basic terms and equations.

Torque can be described in ft-lbs (as we know it). It's the rotational force (in lbs) applied across a 1 foot lever arm. So if you're torquing down a bolt and apply 1 lb of weight on the stub end of a footlong wrench that equals 1 ft-lb of torque.

Power equation is:



Where
P(t) = Power(as a function of time) in watts. Can be converted to horsepower by multiplying by a conversion factor. Either way, watts and horsepower describe a unit of power. The "function of time" part means there is a unit of time on the right side of the equation (in the "w").
T (Greek symbol for Tau) = Torque in the unit of Newton-meters. Can be converted to foot-pounds using a conversion factor. Either way, N-m and ft-lbs describe a unit of torque.
w (Greek symbol for omega) = angular velocity in radians (# of circles of rotation) per second. Can be converted to frequency in rpm using a conversion factor. Either way, angular velocity and rpm describe units of rotation over time making the Power equation a function of time (as mentioned earlier).

Essentially, horsepower is torque multiplied by rpm. But the equation above assumes everything is in metric units (watts, N-m, rad/sec) so we have to convert everything to English units (horsepower, ft-lbs, rpm). That horsepower to torque relationwith all metric-English conversion factors lumped in becomes:



(f = frequency in rpm which is the analog of angular velocity [w] in units in the first equation)


TL;DR: hp = torque x rpm / 5252

[ZDan]

Originally Posted by switchlanez

Power equation is:

If power is a function of time, then so must be either torque and/or rpm.

If torque and engine rotational speed are constant, not varying with time, then power P = T*w (should be a tau and an omega there, but no greek symbol font available!), torque multiplied by angular rotation speed, not a function of time.

You could have an expression for power varying over time shown as P(t), but then you would have an equation in terms of time "t".
Saying P(t) = T*w doesn't make sense, as there's no "t" in there, and if T and w are fixed, so is P.