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Horsepower doesnt mean $&^$
#11
another comparison



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#12
I'd like to know how much torque a horse puts down
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#13
^^million dollar question!
Understeer: When you hit the wall with the front of the car.
Oversteer: When you hit the wall with the rear of the car.
Horsepower: How fast you hit the wall.
Torque: How far you take the wall with you.
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#14
Torque will give you that low end power that can jump you off the line faster but horsepower is what you need to at higher speeds. If you notice in the video you posted the GTR was catching up pretty quick with out much trouble where as the truck was pretty much done.

The reason vtec exists is so that these torqueless motors can still speed up even though they have no torque. This meant that Honda motors could get great gas mileage and still pass people on the freeway if needed.

The horsepower means something and so does torque but power to weight ratio is way more important than either. The lighter the car the less torque needed to launch it and the faster it becomes with more horsepower. Too much torque in a light car and you will never get off the line let alone keep it strait without some heavy mods to keep the power to the ground. The heavier the car the more torque is needed to move the car initially and the more horsepower is needed to keep it moving faster.

anyone argueing that one is better that the other is just looking for a reason to justify their choices.

"its not how you stand by your car, its how you race your car. you better learn that." - JaRule

PS. torque in a car that stays above 6k when shifting does nothing for you if it drops off at 6k. Most hondas in drag racing see their torque once in first gear and barely see it for the rest of the 1/4 mile. It no longer becomes a deciding factor in that case.
"Damn, this thread got 9 kinds of gangster real quick." - Artik Guns
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#15
^^

I totally see your point...

But

what would happen if the truck had longer gears to sustain the high speed?

According to the vid, the diesels only rev to 4k area and make half the HP as torque..

So if this were true, if the truck had a longer final drive, it would hold it own at the end of the track..
So another question...

Since honda engineers made the B18b and paired it with the longer geared LS trans, why?

I do know they needed the flagship line to be better then the honda counterpart, but since the LS makes more torque then the typical Si, would this be why they used the longer gears?
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#16
Hp and tq are both just mathematics number from speed and time tq is what gets something moving but hp keeps is moving, tq and hp are both effected By gearing a motor will not make the same tq and hp in 1st as it will in 5th the trans is a tq and hp -+multiplyer electric engines can teach you alot about "power"
And there are many other ways to measure power then just tq and hp
As far as the honda motors even if you put a ls in a si the si with the b16wold still be faster, it revs higher and makes more power one of the reasons ls has the longer gears is because of it's low rpms,and vise versa with the si
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#17
(02-28-2012, 01:44 PM)EsotericImage Wrote:  ^^

I totally see your point...

But

what would happen if the truck had longer gears to sustain the high speed?

According to the vid, the diesels only rev to 4k area and make half the HP as torque..

So if this were true, if the truck had a longer final drive, it would hold it own at the end of the track..
So another question...

Since honda engineers made the B18b and paired it with the longer geared LS trans, why?

I do know they needed the flagship line to be better then the honda counterpart, but since the LS makes more torque then the typical Si, would this be why they used the longer gears?

Torque is the amount of force that turn the wheels where as horsepower is measure of work the motor goes through to put power to the ground.

that is why motors with a lot of torque do not have a lot of horsepower and vica-versa. It is hard to have the best of both worlds without a lot of money, time and the right motor.

Even with a longer gear it will take a motor with less horsepower LONGER to reach redline thus slowing down a vehicle with more torque than horsepower.

The B18b does make more torque but also has less horsepower and limits at 7,200 rpm where as the B16a2 has more horsepower and limits at 8,400 rpm. The gear ratio of the B16a2 is shorter so you can get the the power band faster and stay in it longer. The B18b gear ratio is so that you can stay in its power band longer.

stock for stock the motors are built to use their strengths. One was built for a sporty car and the other for hauling the kids. You can not compare two different motors built for two different purposes equally. That is like trying to compare apples and oranges and saying oranges taste better. It is a matter of opinion at that point and everyone has their own.

Trying to force your own down the throats of others doesnt help the issue. All that video showed was that a vehicle with torque will get off the line much faster than one with less and a vehicle with high horsepower will catch up to the one with more torque.

on the freeway that truck would have no chance against that GTR. Are we even sure the GTR brake boosted like the truck? how is one video of ametuer racers any proof?

On a serious note, torque is a very powerful tool for racing, but it is not the deciding factor of everything. It is only a small part that makes up the whole. I do not care for torque in my honda. If I wanted torque I would have gotten a domestic muscle car or a turbo diesel. i would rather rev my motor to the sky and pass those torque monsters in the corners than worry about it having no torque.
"Damn, this thread got 9 kinds of gangster real quick." - Artik Guns
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#18
well its no secret that once the vehice is in motion it takes 50% less power to accelerate once in motion.. thats why electric motors can out produce and engine for efficiency..


but some good info here..
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#19
I understand all views but I'm with rob on this one. I to get tired of certain honda nerds who think horsepower is everything and torque numbers never crossed their mind. And then are puzzled when thier b16's get murdered on the streets lol.
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#20
What this all boils down to is, as far as maximum automobile acceleration is
concerned, all that really matters is the maximum torque imparted to the
ground by the tires (assuming adequate traction). At first glance it might
seem that, given two engines of different torque output, the engine that
produces the greater torque will be the engine that provides the greatest
acceleration. This is incorrect and it's also where horsepower figures into
the discussion. Earlier, I noted that the torque and horsepower peaks of an
engine do not necessarily occur simultaneously.

Considering only the torque peak neglects the potential torque multiplication
offered by the transmission, final drive ratio, and tire diameter.
It's the torque applied by the tires to the ground that actually accelerates a car,
not the torque generated by the engine.
Horsepower, being the rate at which torque is produced, is an
indicator of how much *potential* torque multiplication is available. In
other words, horsepower describes how much engine rpm can be traded for tire
torque. The word "potential" is important here. If a car is not geared
properly, it will be unable to take full advantage of the engine's
horsepower.

Ideally, a continuously variable transmission which holds rpm at an engine's
horsepower peak, would yield the best possible acceleration. Unfortunately,
most cars are forced to live with finitely spaced fixed gearing. Even
assuming fixed transmission ratios, most cars are not equipped with optimal
final drive gearing, because things like durability, noise, and fuel
consumption take precedence to absolute acceleration.

This explains why large displacement, high torque, low horsepower, engines
are better suited to towing heavy loads than smaller displacement engines.
These engines produce large amounts of torque at low rpm and so can pull a
load at a nice, relaxed, low rpm. A 300 hp, 300 ft-lb, 302 cubic inch
engine can out-pull a 220 hp, 375 ft-lb, 460 cubic engine, but only if it is geared
accordingly. Even if it was, you'd have to tow with the engine spinning at
high rpm to realize the potential (tire) torque.

As far as the original question ("Should I build my engine for torque or
horsepower?") goes, it should be rephrased to something like "What rpm
range and gear ratio should I build my car to?". Pick an rpm range that
is consistent with your goals and match your components to this rpm range.

So far I've only mentioned peak values which will provide peak instantaneous
acceleration. Generally, we are concerned about the average acceleration
over some distance. In a drag or road race, the average acceleration between
shifts is most important. This is why gear spacing is important. A peaky
engine (i.e. one that makes its best power over a narrow rpm) needs to be
matched with a gearbox with narrowly spaced ratios to produce its best
acceleration. Some Formula 1 cars (approximately 800 hp from 3 liters,
normally aspirated, 17,000+ rpm) use seven speed gearboxes.

Knowing the basic physics outlined above (and realizing that acceleration
can be integrated over time to yield velocity, which can then be integrated to
yield position), it would be relatively easy to write a simulation program
which would output time, speed, and acceleration over a given distance. The
inputs required would include a curve of engine torque (or horsepower)
versus rpm, vehicle weight, transmission gear ratios, final drive ratio, tire
diameter and estimates of rolling resistance and aerodynamic drag. The last
two inputs could be estimated from coast down measurements or taken from
published tests. Optimization loops could be added to minimize elapsed
time, providing optimal shift points, final drive ratio, and/or gear spacing.
Optimal gearing for top speed could be determined. Appropriate delays for
shifts and loss of traction could be added. Parametrics of the effects of
changes in power, drag, weight, gearing ratios, tire diameter, etc. could be
calculated. If you wanted to get fancy, you could take into account the
effects of the rotating and reciprocating inertia (pistons, flywheels,
driveshafts, tires, etc.).
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