Skythe

A very thoughtful response, of which I'm very appreciative. I cannot argue with you on any of these points. In my post I did neglect the "over time" and RPM factors becuase I think of these as understood. What I was thinking when writing all that up is somewhat relative to the "chicken and the egg" paradox.

So what comes first, torque or horsepower. According to the formula horsepower is dependent on torque. One creates the other, is what I'm suggesting. And, with that reasoning I question the marketing tactics of companies that fabricate mods and boost upgrades that advertise based solely on peak horsepower results and subsequently the consumer base that follows with the same reasoning, that the only thing that matters is peak Hp and completely neglect everything else under the curve. Like with an exhaust mod, so what if you all you get is 3 or 4 peak Horsies, what about the rest of the benefits...for instance, maybe you got 3 or 4 through the majority of your RPM band...or maybe you only got a max of 5 lbs under 4K RPM. This is the information I'm more concerned about.

Horsepower is relative to the amount of torque the engine is producing at some RPM with an element of time. I'm asking...shouldn't be more concerned about that factor that horsepower is dependent upon, especially since most will agree that torque is what moves you and the car?

playdoh43

nope, as i have stated in post #2, peak torque is also just 1 point on the powerband, it hardly says anything about how fast the car is. the problem with the inacuracy of peak hp is not that its based on torque, its that its just a single point.

(torque+hp)/weight ratio is IMO a good measurement if you want one number to describe how fast the car is. this sort of balances out the high reving low torque engines like the renesis and Low reving High torque engines like truck engines and take into account the weight of the vehicle.

rotarygod

We could use torque or horsepower numbers. Either is fine. Using both by car manufacturers confuses many people but it still does tell us something useful. Knowing that a car makes more low end torque at a lower rpm also means that we are making more horsepower at that rpm as per the mathematical relationship. It is hard to convey low to midrange power vs high end power if we use only one figure as a reference. This is what makes them useful. Knowing how they relate mathmatically is a very important factor that most people don't know about unfortunately.

To say that torque does work when you step on the gas is technically incorrect. As has been pointed out torque is a measure of resistance to twist and has nothing to do with motion. Horsepower is amount of work done per unit of time. You can't do work without time therefore when you step on the gas it is technically horsepower that moves you. It makes no difference that you can figure out torque from this number. It still has a resistance to twist which is what the torque number is. It still isn't doing any work.

To say that a semi truck uses torque and not horsepower to do work is also incorrect for the exact same reason. Figure out what their peak torque is and plug it into the formula to determine horsepower. That will tell you how much horsepower it takes to do the same job and as stated above, it is horsepower and not torque that does work. If you had a lower peak torque engine that made the same horsepower at the semi's torque peak, it could also pull the same load.

Although horsepower technically is the only thing that should tell us what is important, the way torque and horsepower are stated tells us more as it lets us know if we have more or less low end and more or less high end in relation to other engines. If we only used horsepower or torque, we'd either only know peak numbers or would have to see a power curve of the entire rpm range.

swoope

iTrader: (5)

i think the ??? is does your ??? matter.

i didnt buy my car for the hp... i got it because it handled well, looked good, shifted like a dream, made cool sounds when it hit 5krpm, could hold 4 friends, and i didnt see it every 15 sec when going down the hiway.

would i like more sure. but not if it got fat, wore out tires got bad gas mileage (you got me on that one) it was designed as a well balanced car, i think people miss that point...

so what does hp have to do with the rx 8??????

you can alway buy more, its like augmentation, doesnt make it more deep.

beers

DarkBrew

The total area under the Torque or HP curve, location of the peak and weight really define any engine.
Marketing has turned HP into the defining quality by which people judge engines and cars these days. To most people performance means straight line acceleration and that is all. Take your average SUV driver: They take corners at a snail's pace but blast down the straights.
Marketing needs to be simple to appeal to the mass market. Imagine trying to explain to the mass market why the RX-8 is such a great driver's car!
As in the 1960s the HP war will be ended by insurance companies, rising energy costs and government regulation while sports cars and car enthusiasts will continue to be a mystery to the average driver.

jeffrx8gt

i may have already posted my bad
the whole thing about horsepower and torque really matters but the driver of the car play a significant role lol
i fooled around with two eclipse v6 gt last week and yet their car is fast off the line but after 7500 rpm i was side by side with them the whole time down the block lol
i think their problem is shifting gear need more practice b4 racing lol

MikeW

Power to load
Engine power + gearing + traction mitigated by weight

Smallest engine + 'biggest' transmission

Mercedes Benz C230 (should be 250) + 7g-tronic (7 forward gears + 2 reverse gears)
=Lexus IS250 spanking