More torque than Horsepower

[wed3k]

you're scaring the kids here

[owequitit]

If you want more torque than HP, you don't have to do anything, because you already have it.

[jm991700]

LOL! Sorry, and thank you.

It was after 1am when I read your original post, and after a semi frustrating 13 hour day, I was not following it exactly.

Then it hit me like a ton of brick while I was sleeping about 10 minutes ago, so I had to get up and post back (yeah, I know, I am weird).

We are both essentially saying the same thing, so we are both right. You are just trying to quantify it differently, and that is where there is a technical mistake.

If you look at the HP equation:

HP=torque x RPM /5252

You will notice that it accounts for 3 things.

1) Force. So yes, we are interested in total force, because this is our torque value. We can have a small force (Honda), or we can have a big one (small block etc).

2) RATE. This is where the confusion comes in. The HP equation takes into account rate of work (RPM) and is thus creating a result that compares apples to apples, and not apples to oranges.

3) The constant. Don't remember off the top of my head where it comes from, but 5252 has a significant meaning. It isn't a random number, and it insures that everything is comparable.

So, I mentioned in my previous post that Torque is simply a force, and does not imply work. This is true, because unless something is moving, there is NO work.

You mentioned the F=m/a equation which is also valid, but the HP equation accounts for these variables.

As soon as we add a rate of work (RPM), then now we are dealing with HP, which goes back to the HP equation.

So.

When we determine that a 5.0 and a 2.0 both have 200HP. That means they ARE both accomplishing the same amount of work because the HP is a measure of work, NOT a rate, and NOT a force. It is an end result.

The 5.0 is doing it by producing lots of torque at low RPM, the Honda is doing it by producing a little bit of torque at a high rpm.

What you said about work vs rate is true.

The 5.0 is applying a lot of force at a slow rate, and the Honda is applying a little bit of force at a fast rate (low vs high RPM).

Now you mentioned that they aren't necessarily doing the same work, which is false, because HP is a measure of TOTAL WORK and nothing else.

Here is where you confused yourself with the example you gave:



Let's say the 20lb guy is a Honda, and the 40lb guy is a Chevy.

Your example takes into account instantaneous work, NOT rate. Why? Because the guy pushing the 20lb rock and the guy pushing the 40lb rock both only go up the hill once.

This means the rate is constant because both went up the same number of times. But you said yourself that the Honda has to leverage a higher RATE. If the Honda has the same RATE (1 trip up the hill), then there is no way the total work done can be equal.

If these were two engines producing HP, and they were both at the same RPM (the same rate), then the guy pushing the small rock would be doing half the work, of the big guy. So what you said is correct there.

Here is the flaw:

Method number one, is to leverage torque. (The guy carrying the 40lb rock)

Leverage #2 is to leverage RPM (the guy carrying less weight, but making more trips).

So that means that in order for the same work to be done, the 20lb Japanese guy would have to go back down the hill, grab another 20lb rock, and then get to the top of the hill at the same time as the guy with the big rock, in order to get the same HP result. That is changing the rate. Making them both do the same number of trips is holding the rate constant.

Or, our small engine would have to rotate twice as fast to make the same amount of HP as the big engine, if it is rated at 1/2 the torque.

So you can see that by virtue of the HP equation, they are creating the same amount of work in 2 different ways, which is what I stated the first time.

Honda is doing less work per RPM, but they are making up for it with high RPMs.

The Chevy guy is doing more work per RPM, but is moving slower, because he is moving more mass per trip.

As long as the HP numbers are the same, then they are both doing the same amount of work.

If you ever have the pleasure of driving a VTEC engine, you will also quickly realize that torque and best acceleration don't necessarily coincide.

The H22 is a good example. Peak torque occurs at 5500 RPM, but the H22 does its best pulling from 5500 RPM till fuel cut at 7800 RPM. It doesn't increase to 5500 and then taper off like a conventional engine.

To some degree that is flawed anyway, because very few engines lose torque so fast that their HP peak occurs at the same place as their torque peak.

In the real world, most engines do their best accelaration between the torque peak, and the HP peak, because that is the region where we have the most area under the curve.

Once we hit the torque peak, we are getting the most bang for our buck. Once it starts to taper off though, we keep increasing RPM's to compensate for the loss of torque. Eventually, we reach a point where if we go any further, we will hit the point of diminishing returns. This point is the HP peak. We have been able to get more work by increasing RPM's up to this point. At this point, increasing RPM's will NOT offset the loss caused by losing torque.

So we are really dealing with a range.

Especially, when you look at a VTEC dyno graph.

If there is a proper VTEC change over, there is NO change in the curvature of the graph. This is because the engine makes peak torque at a certain RPM, and it continues to produce no more than peak torque until cutoff, so by superficial analysis only, you would expect the torque peak to be the biggest point of peformance.

But it is not. You will see HP continue to rise, and acceleration continues to go up. If we are past peak torque and what you say is true, then how can that be?

The answer is the RPM's are going up fast enough to compensate for the slight loss of torque that occurs.

That gets back to total area under the curve, which gets back to my previous post.

This is only one aspect of total performance.

The next biggest step is choosing the correct gearing. This is why Honda needs short closely spaced gears in order to accelerate effectively.

They need to A) get the engine to that RPM range faster, and B) keep it there.

That is why most Hondas have gears and final drives so low, a muscle car guy would be shocked.

It is also why most V8's can have widely spaced tall gears, and STILL get the same acceleration. They are making use of that nice fat torque curve that runs from low RPM's on up.

The most pedestrian Accord has a 4.062 rear end. 3.73 at the rear end for a V8 guy is considered up there.

As long as the gearing keeps the car in the best part of the curve, and the HP to weight ratio is the same, both methods WILL produce the same result.

*Just as an interesting side note, the next thing to discuss would probably be how low gearing effects top speed, and how that automatically gives V8's an advantage.

But again that isn't necessarily true. A good example is an H22 with an Accord tranny. In spite of the comparatively low gears, there is enough RPM potential in a stock H22 to run over 200MPH on an F22 tranny.

The problem is that the vast vast majority of cars run into a drag limitation long before they ever hit the top of their gears. By virtue of the fact that drag increases with the cube of the speed (you need 8X more HP to double your speed) that is as true for V8 guys as it is for Honda guys.

Wow, u went left field on this one. Im explaining just the theroy of horsepower and torque. If u look at a automotive book, horsepower is the rate of work being done, Which is work done over time. U got started explaining a lot of other stuff.Im just coveing the basics, u went into to much. I know about gearing and rpm and things like that, i have to b/c im in a motorsport engineering program. The reason that a 200hp honda and bit a 200hp mustang is because the honda weight much less. If u want to get into whats going to win, then its more to it then torque and horsepower. ITs tires, suspension, throttle responds, etc.

[ilovemycb7]

I've always wondered about torque vs. horsepower.

After reading all of this I'm starting to understand. But, why do you feel torque so much more. Like if I floor our pushrod dodge v-8 with 335 tq and 240 hp I feel so much but not to much speed increase happens. But when I floor my cb the opposite happens. /

[texotic]

damn good into thanks alot owequitit

[owequitit]

Wow, u went left field on this one. Im explaining just the theroy of horsepower and torque. If u look at a automotive book, horsepower is the rate of work being done, Which is work done over time. U got started explaining a lot of other stuff.Im just coveing the basics, u went into to much. I know about gearing and rpm and things like that, i have to b/c im in a motorsport engineering program. The reason that a 200hp honda and bit a 200hp mustang is because the honda weight much less. If u want to get into whats going to win, then its more to it then torque and horsepower. ITs tires, suspension, throttle responds, etc.

Yes, and you missed my point entirely.

HP IS the rate the work is being done.

That RATE is based on TORQUE AND RPM. They both have an equal affect on rate.

So if we increase Torque and keep RPM the same, we increase the rate.

OR

If we increase RPM and keep torque the same, we also increase the rate.

And yes weight has a lot to do with it, but when you take a swapped 200HP CB7, with 200HP and 158lb/ft of torque, and then take a V8 powered Camaro, with around twice the torque, but only a 300lb weight gain, you will see that the Camaro has a better torque to weight ratio, but an inferior HP to weight ratio.

And the Accord is likely to be faster.

So which one really accelerates the car?

Torque to weight, or power to weight?

Obviously there are other variables in play, but we aren't discussing the other variables, we are discussing Horsepower and Torque.

[Fake Thug]

The reason that a 200hp honda and bit a 200hp mustang is because the honda weight much less. .

LOL..All that talk about why a honda beats a ponycar with same power is very left field when you leave out the most important factor..

[GreenMadness]

We can now all see the flaws of U.S Customary Units... HP is not a unit, it is a comparitive scale created to relate the power of mechanical engines to something the common person could relate to. (When the mechanical engine first became comercialized)

US customary- though it may help to clairfy

Force- Pound (lb)
NOT to be mistaken for MASS- slug (lb-s^2/ft)

Power- pound-foot per second (lb-ft/s)
NOT to be confused with Intensity of force (pound per foot)

Torque (Magnitude of twist a force has) - pound-foot (lb-ft)

Energy or Work - foot pound (ft-lb)

*****PLEASE NOTE: here you can see Torque and Work DO NOT HAVE SAME UNITS****** meaning Power being the "rate of work" wrong in terms of units.

^^----Very Confusing indeed-----^^


..... so as you can see, HP doesn't fit into any real mesure or unit... its a quantity that can be mesured and closely figure from a real quantity (Torque)


Where as in the S.I Units

Mass- Kilogram (kg) [just so happens to be the same a weight... unlike U.S]
Force- Newton (Kg*m/s^2)
Energy;Work- Newton-Meter (N*m)= J (Joule)*****ALSO = torque
** 1000 J = 1 kJ

Power (rate of work)- watt (W)- J/s = N*m/s
**1000W = 1KW

Which is why the S.I system of quantitating power is so much better...

So i feel that is where the problem is coming between real life examples and the on paper calculations... sorry if this is irrelivent or a thread jack, just though it may help in some very messy confusion.

[owequitit]

We can now all see the flaws of U.S Customary Units... HP is not a unit, it is a comparitive scale created to relate the power of mechanical engines to something the common person could relate to. (When the mechanical engine first became comercialized)

US customary- though it may help to clairfy

Force- Pound (lb)
NOT to be mistaken for MASS- slug (lb-s^2/ft)

Power- pound-foot per second (lb-ft/s)
NOT to be confused with Intensity of force (pound per foot)

Torque (Magnitude of twist a force has) - pound-foot (lb-ft)

Energy or Work - foot pound (ft-lb)

*****PLEASE NOTE: here you can see Torque and Work DO NOT HAVE SAME UNITS****** meaning Power being the "rate of work" wrong in terms of units.

^^----Very Confusing indeed-----^^


..... so as you can see, HP doesn't fit into any real mesure or unit... its a quantity that can be mesured and closely figure from a real quantity (Torque)


Where as in the S.I Units

Mass- Kilogram (kg) [just so happens to be the same a weight... unlike U.S]
Force- Newton (Kg*m/s^2)
Energy;Work- Newton-Meter (N*m)= J (Joule)*****ALSO = torque
** 1000 J = 1 kJ

Power (rate of work)- watt (W)- J/s = N*m/s
**1000W = 1KW

Which is why the S.I system of quantitating power is so much better...

So i feel that is where the problem is coming between real life examples and the on paper calculations... sorry if this is irrelivent or a thread jack, just though it may help in some very messy confusion.

No, you are correct, nothing necessarily converts easily.

But realistically, the whole point of the conversation is that there are 2 ways to make Power. 1) is to create more torque, and 2) is to create more revs.

They can both be equally effective, since what we are really interested in is area under the curve.

If we make the curve taller with more torque, we will see increased area under the curve, and thus acceleration.

If we increase the length of the curve with more revs, we will still see more area under the curve, we simply are getting it a different way.

[cloudasc]

Then without increasing the rev range on our f22 motors, what modifications can we do to increase the area under the torque curve, that would put our peak torque closer to our 6k+ red line, vs our stock 4.1k peak torque on our f22 motors? I think that is the true underlining question.

[owequitit]

Then without increasing the rev range on our f22 motors, what modifications can we do to increase the area under the torque curve, that would put our peak torque closer to our 6k+ red line, vs our stock 4.1k peak torque on our f22 motors? I think that is the true underlining question.

You can increase volumetric efficiency, and thermal efficiency.

That is the other way that Honda makes big HP numbers out of a small engine.

They flow air very well, and since an engine is essentially an air pump, the more efficiently we flow air, the more power we can make.

They also extract energy from the combustion event very efficiently compared to some other designs, although it is harder to increase this efficiency, with the most common way being an increase in compression ratio.

This is where the two methods come into play again.

To some extent you are limited in the HP and torque you can produce with a small displacement engine. Once you reach 100% volumetric efficiency (not possible in the real world), you will not make any more power or torque, unless you increase the redline.

That is why high HP small displacement NA motors like Honda's typically have stratospheric rev limits. They need to flow more air to make more power, and the only ways to do that are to increase displacement (more air pumped per revolution) or increase revs (more air pumped in the same amount of time).

It also explains why Formula 1 engines have to spin to 18,000-20,000 RPM in order to make 800+HP, but a NASCAR engine can do it at 7,000-8,000 RPM.

Interestingly, Formula 1 engines are now spinning so fast that if they increase the speeds much further, airflow through the engine is going to have to be supersonic, in order to keep up.

That is going to be bad...

Also, the build quality of Honda's engines is such that they come stock with things that most engines don't have until they are full on built engines. For example, a forged crankshaft.

They also have machining tolerances that are so tight, a lot of professional race engines are just starting to reach the same level of accuracy.

But I digress...

Depending on which F22 you have, there are many ways to get increased power.

The F22A6 manifold is better than the A1 and A4 manifold. The F22A6 cam is better than the A1 and A4 cam.

You can put an H23 Intake manifold onto an F22 also, or you can put an H series plenum onto an F22A6 manifold.

Those will both allow the engine to breath better in the top end.

Put a good size free flowing exhaust, intake and cam on the car, and you can see near stock H22 power levels. Port and polish the head, and you can see more. The intake ports on the F22 flow extremely well. The exhaust ports can use some help though.

Of course, those mods are going to require that you rev higher too, which on a healthy F22, 6500-7000 probably isn't unsafe, as long as you are meticulous about your maintenance.

Look at HondaFan's red project. Read the tech section. There is a ton of information here, but you have to go look for it.

[Razif]

good rite up...2 thumbs up!!!!

[lo-specials]

How/What parts or things could I do, to give my car more torque, than horsepower? Have any ideas, just lemme know.

ITB's or am I mistaken?