engifineer

It still sounds like people are missing the point. HP is NO more important than torque which is NO more important than RPM. Torque and rpm are equal in importance to produce HP. If you are tryint to produce the number 6, which number is more important in the equation 2 x 3 = 6 ??? Neither, cause if you remove one you remove the answer. HP CANT be any more important than torque because it is the end result of the torques effect. It is the combination of the torque with its position in the powerband that creates HP. Again, it is a system, you dont define it by its individual components alone.

Q_Z

ITZ ALL ABOUT TORQUE...THATZ WAT MAKEZ UR CAR JUMP!!!!

cocobware

okkk, if torque doesnt matter, race a 350z (the manual is listed at 297hp and 270something torque) and a 2006 Mustang Gt (300 hp and 320tq) and both are similar in weight, and then tell me tq doesnt matter. the mustang will own the 350z....and i know its hard to compare a v-6 to a v-8, but if torque doesnt matter then it should be a close race, but the mustang takes the win

hahaitzskippy

TQ matters when yo uare at a stop because TQ helps get the car moving.
the reason why the mustang may have the lead is because it has more TQ to get it off teh line and going...

taking the lead from the beginning is VERY VERY important in drag racing

senseiturtle

It will be a close race. Greg and Jason, 2 friends of mine, race their respective cars... a 350Z and a 06GT. They both run consistent high 13's.

Similar weights, similar gearing, both RWD... The 350Z actually traps a little higher, and it's a 27x HP 350Z, not the new 300hp models.

There's too much involved in your situation... but if torque is all that mattered, then you'd be able to trounce S2000's in a bolton tC. Not the case.

savior

ok lets end this thread now:

torque matters when racing from a dig
hp matter when racing from a roll

combine the two and you have one sweet ride
disregard one of the above and your car will be really awkward

**however an increase in torque usually means an increase in hp (visa-versa)

there relationship directly effects the other

---the end---

hahaitzskippy

well said

engifineer

Still misses the point. You have to 100% have both. One is not more important that the other. torque is ALWAYS important as HP relies on it and rpm 100%. It is the use of the tq within the band that creates power. Period. Really, it is all summed up very simply by the formula which has been stated over and over. TQ is a component of HP so you CANNOT say one is more important that the other, ever. If you really want to get down to it, you could just as easilly state that rpm is the most important (which would be equally as wrong as any argument for the other two).

Of course combine the two, since you cant create hp without tq.

An increase in tq at a given rpm ALWAYS means more hp at that rpm.

Create more tq across the band and keep your redline up (ie a small block chevy built to perform) and you can put all the low tq, 300WHP@8000 rpm engines you want against it in a drag race and lose as long as the small block is built to run upwards of 6500 rpm and has more tq the whole way.

Its all application and where you use your power. But, I do agree, its time to end this because no one is really looking at the whole problem, they are picking a peice and defending it when they are actually all pointing out the importance of all parts together. Read all the arguments, put them together and you will have a decent point about evaluating a whole system

cmndrjamesbond

Still wrong.

djct_watt

I love this thread.

It matters that you have torque. . . but it's not the most important number. If your motor revs to 40,000 RPM, you'll be doing plenty fine with just 60lb/ft.

Of course that is a rediculous number, but being that most high performance motors (read: race motors) get into the 8,000RPM+ range, the HP is the critical number.

Power, simply put, is a force applied over time. HP is force (torque) appled over time (rev/second). Think of it as a race between a sprinter and a weight lifter. Both need to be able to exhibit force, but in a race, the one who applies it faster wins.

I believe that's why you often see torque (like a weight lifter) emphasized for vehicles that need to tow heavy loads, and HP influenced on performance vehicles.

Then again, I think gearing can technically accomodate both and translate HP into torque and/or vice versa. I'm not sure about that last one. Engifineer? You probably know this. Is this true or false?

cmndrjamesbond

Power is going to be constant through gearing. Torque and Rotational Speed are inversely related through gearing.
Example: In 5th gear, at a given engine rpm/horsepower the revolutions at the wheel are higher than in 1st gear. However, the force exerted by the tire (found by multiplying the radius of the tire by the torque) will be much higher in 1st gear

djct_watt

That makes sense.

engifineer

Then please "correct" me.

Sorry, but is is simply correct. You cant have one without the other and you cant say one is necesarilly more important, period. Dont call me wrong without the mathematical explanation to prove it. Physics explains it very simply.

Please enligten me and explain how one peice of the system is more important than the entire system together, because that is the point I make.

killerxromances

Neither whp or wtq matters. You have to have the right combination of both, with gearing to compliment this with a good suspension/tire combo. Not one specific thing wins races, its a combination of everything.. Of course, driver plays the biggest out come in everything.

Another thing is weight. If you have a 1,500lbs car, and have 200whp and 90wtq for an example, it doesn't matter you have such a low amount of torque because the car doesn't need much "pull force" to be able to run low numbers on the 1/4.

An easy way to think as far as just the whp wtq debate is this. Whp is the power of your car, wtq is how much "strength" the power has. Its kind of general and 4th grade as far as giving information goes. But its the truth. Which is why you can take two 3,000lbs car. Identical gearing, suspension and everything. One has 300whp and 150wtq, the other has 150whp and 300wtq. In the end, its going to be a very close race. Torque is usually used for towing or hauling a ton of weight, not racing.

engifineer

The reason you see HP emphasized is not because it is more important on a vehicle, it is because it is the measure of how the torque is used through rpm. That is what I am trying to say... here is a very nice analogy


The MASS of an object is 1kg

The WEIGHT of that same object on earth is defined as :

W = mg --> W = 1(9.8 ) = 9.8N

Now, who is going to tell me that the newton is more important than the kg or vice versa??? No-one, because they really arent comparable as far as "importance" in the grand scheme.

In order to have HP you must have TQ and RPM.
In order to have W you must have m and g

Again, it is a system. It needs to be treated as one. Do you have a ton of tq to start with? If so, then you dont need as much rpm to get you going, and you can pull harder with higher gears (you dont need a short @$$ 1st gear... meaning less shifting) up to the point that you run out of rpm or tq.

Do you have a super high redline to start with? If so, then you possibly (depending on the shape of the power curve) dont need as much tq to compete, but you probably want shorter gears to keep up the rpm if you have a lower tq to work with. That means more shifting, but you can produce power with a small displacement engine.

If you have a proper mix of both, you will school either of the first two mentioned. The issue you run into with too low of a tq number is that piston speed runs into its limits based on the weight and materials used. So if your tq is too low as mentioned by dj, you will need an ungodly high redline to even compete which definitely has its limits, and will be shifting as quickly as you reach the next gear to keep you in your power band.

I am not arguing one is more important that the other (cause it isnt) I am arguing that the argument itself makes zero sense.

senseiturtle

I think its time to lock this thread.

killerxromances

I really don't understand why this thread was started to begin with. This topic has already been beaten down atleast twice that i can recall.

hahaitzskippy

it was a FAQ...

hahah not meant for a debate

cmndrjamesbond

I'm going to present this in metric units, since nobody seems to know what a slug is. Torque is the cross product of a force (N or kg*m/s^2) with a moment arm (m). Taking the torque and multiplying it by revolutions/second (hz) gives you units of (kg*m^2/s^3or Watts) which is power. As for an example as to why worrying about how much torque a car makes is moot (other than the relative shape of the torque curves), take the following example. Assume two engines, one putting out 160hp and 160 ft*lbs of torque at 5252 rpms. Compare this to one putting out 160 hp but only 80 ft*lbs of torque at 10504 rpms (thats double the previous number for you math majors out there). Once again, assuming that the shape of the two horsepower curves is identical, you will get identical performance out of the two engines if the second one is geared so that both go 30 mph (arbitrary number) at redline in first gear. The power that you will putting down at redline will be identical for both cars. And for the reason stated above, the torque that each puts down will be the same. If you want a real life comparison, take the dyno chart from an S2000, multiply the torque curve by 1.5, while at the same time compressing the rpms so that it only spans 6000 rpm instead of 9. Compare it to the dyno from a more conventional engine making 240 hp (early Altima if you can find this chart).
You'll find that the two are pretty similar. The rpm range and torque are affected by gearing.
I'm not saying that a tC putting down 180 ft lbs (5000 rpm) of torque and 200 hp (at redline) will be just as fast as one making 200 ft lbs (4000 rpm) of torque and 200 hp (at redline). The second example is making more power early in the rpm range, and the same amount later on. However, when you consider two cars with similar shaped horsepower curves over different rpm ranges, horsepower is a fair comparison assuming the cars are both geared appropriately.

djct_watt

That is absolutely incorrect. Wtq is the amount of force a car can exert, or it's "strength." Whp is the car's ability to apply that force over time. Scientifically, that is the DEFINITION of power.

Torque is no different of a measurement than the maximum amount of weight you can lift. It takes more power to move 50 lbs 10 feet in 10 seconds than it does in 30 seconds. Torque says absolutely nothing about how quickly you can apply your force. That's where HP comes into play. HP is a measurement using time, defined by revolutions per minute. The higher your engine can rev, the more power it can make with the same amount of torque.

I'm sorry to say, but in this thread, engifineer is the only one who has been consistently correct. And since I constantly argue with him, that says a LOT. He know EXACTLY what he is talking about.