[QUOTE]Originally posted by honda606
[B]

 

Just because I disagree with you makes you not like my attitude?? Sorry for that.

I agree with you that in real world situations, performance can vary...but during controlled testing, things should be almost equal or somewhat similar at the worst. My example was meant to demonstrate that every time you test a component, it will perform very similarly. It will fail or flex at the same points or rates, respectively. That is why tests exist...correct me if I'm wrong but it's meant to be a controlled environment is it not?

 

Some magazines go out of their way to correct for atmospheric pressure, ambient temperature, road surface conditions, prevailing winds, etc. Who's to say their formula is precise? Well at least they try.

But that doesn't mean their articles make for interesting or educational reading. A magazine like Motor Trend might as well mail me a road test review and skip the rest, there is very little meat in the stew.

Car and Driver tends to tell it like it is, and I never see them catering to a certain brand. When they compare cars they typically report the actual performance at that point in time, not trying to correct for some variables and please the scientists shopping for a car. Instead they fill their magazine with subjective opinions and qualitative analysis. I like that.

Peace!

 

i think there is very varied opinions about this, some people say it has gobs of torque othere say it is deficient. i currently drive a car that puts 270tq at the wheels so will i feel like im idling when i punch it off the line?

 

[QUOTE]Originally posted by news2kroller
[B]i think there is very varied opinions about this, some people say it has gobs of torque othere say it is deficient. i currently drive a car that puts 270tq at the wheels so will i feel like im idling when i punch it off

 

He's got you there, integrale. Case in point; everyone makes mistakes...

 

the thing im worried about is if i sell my amg mercedes for an s2000 will i regret it? im still trying to decide between m coupe and s2000. ebery time i drive the s2000 it feels so right and i havent ever been above 6k rpm's !!!, it jsut felt so blanced and precice. but im used to cars that are very fast, e36/e46 m3 my amg benz, chipped s4's etc, i just dont want to get bored of the car in a few months, am i gonna regret this?? i like to race sometimes, but maybe i will mature when i realise u turns at 40 are more fun

 

On my way home tonight I took a friend for a ride. Needless to say, he was very impressed. When I dropped him off, he talked me into launching once in the parking lot. After revving to about 6k rpm and sidestepping the clutch, I took off like a rock out of a sling shot. Holy shit this car is fast! Nice big fat burn out across the parking lot also. I have read how some of you launch your cars at about 6k and I really didn't want to abuse my car like that, but.... Who ever says this car is slow, you really have no clue. And as for torque, Torque is a measure of Horsepower at a certain RPM. I am going to see if I can dig up the proper equation and end this thread once and for all.

By the way Integrale, you sure are quite the defensive little guy, aren't you?

 

work done = T*A, where T=torque and A=angular displacement.

power(P) = work done per time = T*A/t, where t=time.

Since A/t = angular displacement rate(w) , P=T*w

w = N [rev/min or rpm] * 2*pi [rad/rev] * [1/60 min/s] = ( pi/30 * N [rpm] ) rad/s

1 hp is defined as 550 lb*ft/s or 6600 lb*in/s

Work everything out, and you will get Power (hp) = Torque (ft*lb) * rpm / 5250, just as was posted before.

This is at the output shaft of the engine, of course. The torque delivered to the wheels converts to an accelerating force. The torque from the engine must be multiplied times the gear ratio, including the rolling radius of the tire, to get the accelerating force at the tire's contact patch

This is why work and power come into the picture. Given two engines producing 240 HP but at different RPM, both will be accelerating the vehicle with the same force if the gearing is such that both cars are receiving the same accelerating force at the tire contact patch. The car delivering the HP at the lower RPM will feel like it's delivering more torque because it seems like it's doing it without too much effort, and there might be more on tap. But probably both cars will have to upshift soon.

My point: Don't forget gearing and the angular displacment rate of the driveline components.

HP is what matters, even though torque is in definition closer to force, which is in everybody's favorite equation F=m*a.

In this case, it's force at the tire patch, not force at the crankshaft that accelerates the car.