What is the derivative of horsepower?

"DC3 LS, will be perpetually replacing cars until the end of time" (dc3ls-)
12/12/2017 at 13:22 • Filed to: None

Is it torque or something else? And if so, can you derive anything from that? (pun fully intended.)

DISCUSSION (15)

HammerheadFistpunch > DC3 LS, will be perpetually replacing cars until the end of time
12/12/2017 at 13:25

This is a math joke. I don’t get those.

Ash78, voting early and often > DC3 LS, will be perpetually replacing cars until the end of time
12/12/2017 at 13:26

Semi related: how about the integral of the power curve to show the area under the curve? Then you could more accurately compare a big NA V8 with a high-revving I4 using a much better metric than peak bhp.

Not my original idea, I think I read it on Jalop about 10 years ago.

/opening a Calculus tutoring franchise called DeriveTime

Highlander-Datsuns are Forever > Ash78, voting early and often
12/12/2017 at 13:28

Hammerheadfistpunch has talked extensively about this very subject.

Highlander-Datsuns are Forever > DC3 LS, will be perpetually replacing cars until the end of time
12/12/2017 at 13:30

Force Per unit time. 1 HP is 550 ft-lbs/s.

DC3 LS, will be perpetually replacing cars until the end of time > HammerheadFistpunch
12/12/2017 at 13:32

A derivative is just the tangential line to a point. Although I probably worded that so that it didn’t make sense.

random001 > DC3 LS, will be perpetually replacing cars until the end of time
12/12/2017 at 13:33

But it’s the tangential line at a point, AT EVERY POINT, which makes another line....or a lot of lines....

HammerheadFistpunch > Highlander-Datsuns are Forever
12/12/2017 at 13:34

cept the math bit. I could never into math, which is why I was a communications major! But yeah, average power would be a great way to compare. Sadly no one publishes power charts...except GM for some reason.

DC3 LS, will be perpetually replacing cars until the end of time > Ash78, voting early and often
12/12/2017 at 13:34

That’s an awesome idea! I wonder if you could also use that with gear ratios to figure which car will have the most torque/horsepower at the wheels?

Grindintosecond > DC3 LS, will be perpetually replacing cars until the end of time
12/12/2017 at 13:34

Please stop drinking before you derive again ....

Highlander-Datsuns are Forever > HammerheadFistpunch
12/12/2017 at 13:37

It is a fantastic way to see how useful the powerband is for normal driving conditions. It would show that an RX8 sucks and a Ford with a 24v V6 is much easier to drive.

DC3 LS, will be perpetually replacing cars until the end of time > Ash78, voting early and often
12/12/2017 at 13:38

I think we need to spam David Tracey’s email until he does an article comparing some motors this way.

Future next gen S2000 owner > DC3 LS, will be perpetually replacing cars until the end of time
12/12/2017 at 13:45

This really gets into partial differential equations.

Depends. HP = Torque*RPM/5252.

If you take the derivative of HP with respect to RPM dHP=(RPM*Torque/5252)dRPM would be HP’=Torque/5252

However if you take the derivative of HP with respect to and arbitrary variable, say x. Then dHP=RPM*Torque/5252dx would be 0.

I’m not sure how useful those would be. You could do dHP=RPM*Torque/5252dTorque would be HP’=RPM/5252.

You could do dHP=RPM*Torque/5252dRPMdTorque. But I think that gets to a constant of 1/5252.

It’s been awhile since partial differential equations, so I’ll need someone to check my work.

WRXforScience > DC3 LS, will be perpetually replacing cars until the end of time
12/12/2017 at 13:54

The time rate of change of the ratio of the horsepower to the rpm.

How quickly your horsepower:rpm changes, not very useful.

davesaddiction @ opposite-lock.com > DC3 LS, will be perpetually replacing cars until the end of time
12/12/2017 at 14:29

I derive pleasure from it.

Shoop > DC3 LS, will be perpetually replacing cars until the end of time
12/12/2017 at 17:38

Turbo lag.