I thought I would share this. I got it off the web somewhere. "Understeer is when you hit the wall with the front of your car; Oversteet is when you hit the wall with the rear. Horsepower is how fast you hit the wall, and torque is how far you take the wall with you."

 

Yep, that's been in my sig for about two months now

 

Sorry John didn't see yours but it's a good one.

 

Haha it's totally fine bro

You know, it IS a pretty accurate summary of each of the four racing terms though.

 

"Horsepower is how fast you hit the wall"

That part is a little misleading. Horsepower is more a summary of the behavior of torque over the car's available RPM range. Not so much a measure of potential speed.

 

Technically speaking...

1 hp ≡ 33,000 ft·lbf/min by definition
= 550 ft·lbf/s since 1 min = 60 s
= 550 × 0.3048 × 0.45359237 m·kgf/s since 1 ft = 0.3048 m and
= 76.0402249068 kgf·m/s
1 lb = 0.45359237 kg
= 76.0402249068 × 9.80665 kg·m²/s³
g = 9.80665 m/s²
= 745.69987158227022 W since 1 W ≡ 1 J/s = 1 N·m/s = 1 (kg·m/s²)·(m/s) Or given that 1 hp = 550 ft·lbf/s,



1 ft = 0.3048 m,



1 lb = 4.448 N,



1 J = 1 N-m,



1 W = 1 J/s:



1 hp = 746 W


cross multiply and cancel out:










= 745.66272 W or 746 W

 

^^^ Courtesy of Wiki

I think it's agreed that HP has a greater influence on top speed than TQ, and vice versa. That, plus thousands of other variables, are why hondas with a J-spec motor can run an 11 second 1/4 mile, but My dad's Navigator could hook up to the rear of one and rip the guts out of it in a pulling contest.

And, in the case of our X-fires, we have good HP and good TQ... hence why we have such fun with the rice rockets.

Hit 'em high, hit 'em low.

 

And in a 1:1 environment that could translate to measurement of the potential for speed.
But with differing gear ratios and powerband shapes, it does not.

That depends on gear ratios. A car that uses long gears to hang in a massive torque band will pull just as well at high speed as a car with short gears and high HP numbers attained via a tall RPM band.

To many vairables to say HP = Speed.

 

Very good points, amigo.

I.E. the C6 Z06... the sixth gear is freaking TALL, but it pulls extremely well even in top gear. Why? Gobs-O-Torque

 

That's why I'm less concerned with HP numbers and base my straightline judgement on the torque curve and gearing.

But even a peak torque rating @ a certain RPM won't tell you if it's a flat or peaky powerband. Look at the Crossfire, the gears are so short you never touch your peak TQ rpm @ WOT. Lucky for us the torque curve is flat as a pancake and we still have plenty of torque near redline.

A dyno curve, curb weight, and summary of gearing is really the only way to tell how "fast a car will hit the wall".

 

All of you are taking this way to literally. This was just suppose to be a sarcastic comment

 

Crap, it's not literal?

I know, I used to race back in the day. Cross-weighting, tuning, etc.; those were all names of the game. One of my SCCA buddies said this joke years ago and I remembered it a while back. I thought it was funny as hell. I drove a truck in SM2 class; understeer OWNED me.

 

I actually became more interested when it became literal...maybe i'm just a nerd, but i'm with opticon; there are very few things in life that are in direct proportion (as one goes up/down, so does the other) of a result. While many things are accepted as direct proportion, very few if any actually are. it's a philosophical school of thought...but to each their own because afterall, ignorance is bliss (no offense).

 

I was told that horsepower is an imaginary number to sell engines. The amount of work one horse could do. This steam engine can do the work of 7 horses, it has 7 horsepower. Torque is the work being done


Not a nerd, so any truth to this??


Justin