Originally Posted by EspritS4s

Good points, and your last paragraph is a good way to some it up for someone looking for a simple answer. Part of the problem in these threads is that people try to over simplify the discussion and / or make blanket statements. This makes it easy to argue on and on and on and ...

Originally Posted by IcemanG17

Well said.....makes sense since so many drag racers like big displacement engines (torque) and-or boost (again more torque)....

it all comes down to how the engine is built & what its goals are! Since the basic rules of getting more HP & torque never change:

1: More displacement
2: More RPM
3: Boost


I plan on conducting a clinic on TORQUE this weekend at Sears Point with my fellow "lemons" racers........

Originally Posted by bcdavis

Well, I guess my Kibort challenge didn't work...

Anyhow, in previous debates, I still contend that there can be a distinction between the
two words, because they don't have to be based on the scientific definition of "torque"
or "horsepower". People get caught up in semantics. People still know there is a
difference between an engine that "pushes them back in the seat", versus one
that accelerates slowly, but when it hits high RPM, builds up a tremendous amount
of power and acceleration. And that can be as simple as gearing. Could even
be the exact same engine. But if it has a specific rear end, specific transmission,
tires, etc, then it can accelerate very forcefully off the line, which people equate
to the word "torque". And they aren't talking about the scientific definition.
They are talking about specific cars being capable of putting a large amount
of power to the ground at low RPM. That's what people consider "torque".
And most people know that torque gets you off the line quickly, and it helps
you accelerate out of corners. If your car has massive horsepower on paper,
but low torque off the line, we know that horsepower is probably at the high
end of the curve, where it's not as effective at getting the car off the line,
or out of a corner. Mainly because the car needs higher RPMs to get it
into the powerband. My main point is that we know that there is a scientific
formula for hp/tq. But most people aren't concerned with the science.
They are concerned with real-world experiences. How a car works
on the race track... And yes, perhaps a specific BMW engine can
rev to 10,000 RPM and make 500 hp. But we also know that if we
are on a racetrack, we might prefer a Dodge Viper with 600 tq.
Because we know that power will be available for a wider range
of the powerband, and at lower RPM, making the car easier to
drive. Now that number might come because of gearing, displacement,
cams, or any number of things. But it's the results people care about.
How easy is the car to drive, and which car is faster around the track?

The better question really would be:

"Do you think a car with power in the high RPM range is faster around a racetrack than a car with power in the low RPM range?"

Originally Posted by IcemanG17

The easy answer is its the same....assuming the low torque car has proper gearing.....and an engine that can spin some RPM's (typical for low torque motors)......then the higher speed engine makes up for its low torque by more time in lower gears which mulitply its torque for the same acceleration....

An example...my old M3 with 4L of displacement, but the ability to spin 8400rpm made 270ftlbs on the dyno....BUT it made it from 3000 to 8000 rpm....however having 7 gears made it never-ever drop below 6000rpm on track...so it was between 300-400whp all the time

Originally Posted by M928

Thats why i gave the 2 cars as an example on how they run.
Look at a GT3 RS 4.0 being 2998lbs in weight 500hp
500 hp 8,250
Max. torque at rpm
339 lb.-ft. 5,750
Curb weight
2,998 lbs


997TT 500 hp
500hp@ rpm 6,000 - 6,500 rpm
Torque
480 lb.-ft. (with overboost 516 lb.-ft.)
@ rpm
1,950 - 5,000 rpm (with overboost 2,100 - 4,000 rpm)

997TT is 500lbs heavier and torque & hp comes in way earlier the car accelerates quicker
Getting both the HP and torque in the earlier RPM range is the most important if you have the traction like all AWD TT car.
They both have same HP but maximum torque is different!
Depends on the application they are used for where you need the torque and maximum hp.

Originally Posted by Duke

The deal is that power is the only thing that matters. And power is a function of torque AND rpm. That means that 400 hp @ 4000 rpm has double the torque of 400 @ 8000 rpm. BUT that doesn't make the 400 hp @ 4000 rpm engine accelerate faster. So many people think torque by itself is important for acceleration which is wrong. Instead of more torque vs power discussions I would just advice you to look at diesel engined cars. Does the diesel powered version of a specific model accelerate much faster than an equivalent model with the same HP but with gasoline engine because the diesel engine have much more torque? No.

Originally Posted by GlenL

The attempt to say which is better is totally framed by the application

Originally Posted by mark kibort

not really. if they are the same weight and the gears allow for the same hp at any speed coming off a turn, then they both will accelerate identically.
The GT3 will have the closer gears keepng the RPM in the power band , almost identically to a wider gear box ratio set that needs the boost and wider HP range to keep up.

Originally Posted by Hacker-Pschorr

Pardon me for not assuming this thread was also including the best engine for hauling gravel across town.

I like fast cars, if I need to worry about pulling a stump out of the ground I'll call my brother-in-law to borrow his F250. I don't see the need to re-design my 928 to also perform such tasks

Originally Posted by jpuzas

Here is my .02 on the topic. If someone offered you two engines and said this one has 1000 lbf-ft of torque and the other had 200 lbf-ft of torque which would you choose if you wanted to win a road race in a 928 all else being equal? I maintain you could not answer the question. The reason is torque is simply a measurement of an engine's ability to twist. The number says nothing about the engine's ability to do Work. Hp tells you how much Work an engine can do. Work is force applied at a distance. Now if I told you one had 1000hp and the other had 200hp and did not tell not tell you which torque number was associated with each engine. You would lose the race if you chose the engine with 200hp.

Originally Posted by bcdavis

But it does demonstrate the concept that you apply power in a specific RPM range, depending on how the car is geared, how heavy it is, etc. So sure, if you have a car with a six speed, computer-controlled gearbox, then yeah, build an engine that makes 600HP at 10,000rpm. But in terms of racing, for the average driver, with an average car, it's better to design your powerband to hit down low. (torque) Which will, indeed, pull a stump out of the ground, but it will also help you get out of a corner faster, without having to shift 3 times to keep your car in a very narrow powerband... Again, this isn't really a debate about what torque means, or what word is best to use. We've gone over that debate a million times on here. The debate is if a car with power hitting down low in the powerband is faster on a racetrack than someone with a car that has power hitting high in the powerband, which means you have to shift more often. I think another advantage to "torque", is the ability to modulate the throttle in a corner to control speed and power, without having to shift to do so... It makes for a smoother driver... IMHO...

Originally Posted by M928

Its about application of where the hp and torque is needed.
Not talking of cars with same weight and gears talking of cars that were made for their particular application.
997TT 500HP more of a street car with some track use lots of torque down low since the all wheel drive can handle it.
GT3 has to have the HP up high as it would blow the tires off if it was setup the same being 2wheel drive.
Depends on application of what the car is used for but if
in a drag race you take the lighter weight GT3 with 500hp,I'll take the heavier 997TT with 500hp see who wins.
You race and know cars in traffic cars don't come off the corner the same only in the perfect world would that happen each and every time.I'd go with the higher torque car with all wheel drive when caught in traffic.
Next debate Supercharge 500hp 928 vs Stroker 928 500hp who wants to start that thread? lol

Originally Posted by dcrasta

HP vs Torque. These 'discussions' always come up on car forums. -tsk -tsk. [What I think I know about this..]

How about this novel concept. There is no such thing as Horsepower. Horsepower is a calculation.

What we are measuring is Force, c/d? How do we measure the Force generated by an engine?

How do we measure Horsepower? We calculate horsepower by measuring Torque. (And doing math)

How do we measure Torque? We measure Torque on the Dyno. Dyno converts the force generated by the rotation of the wheels into work (twisting forces) that can be measured.

Horsepower is important because it relates to how much work can be done quickly. A value that is determined by calculating the rate the torque is being exerted [how quickly is this work being done.]
.
This is why dyno HP and Torque curves converge at 5252 rpm. Its Magic.

HP = torque*5252/RPM

At least that's how I understand it.

There is no spoon.

Originally Posted by GlenL

"The deal is..."

His deal is wrong.

What matters is force between the tire and the road.

Once the car is moving and the force is applied you either "have" power or "need" power but those are semantics. Just words. And people get wrapped up in having their words be the right words.

The whole argument is really pointless. A torque at an RPM means you have power and a power at an RPM means you have torque. Simple and reflexive.

The argument over power vs. torque is also rooted in the convenient coincidence that in the USCS unit system the two peak numbers (HP and lb*ft) are often similar. This leads to pointlessly silly arguments.

Another factor in this silliness is underlying assumptions of how an engine performs. Our sportscar engines tend to rev high and they're used for road racing. This leads to a perspective on what performance should be. If the underlying domain were, say, giant dump trucks then everyone would agree that torque was the only thing. The attempt to say which is better is totally framed by the application, but no one ever says "for my purposes" they put it in absolutes.

On thing is for sure, a torque graph from the dyno is much more informative than a power graph. Multiplying by RPMs obscures the change in torque that's how best to evaluate the health of an engine.

Originally Posted by mark kibort

Ill take the ligher car any day of the week, regardless of its HP curve. (brakinga nd cornering are going to the advantage of the lighter car) but, with todays gear boxes , being closer ratio, wide HP cuves (lots of torque down low) doesnt really matter, even off turns at different or slower speeds, because its easy to be in the meat of the HP curve, and if you are near the meat of the HP curve, you are accelerating at the same rate as the other guy if you both are near the same HP output.