How do you increase Torque?

[Slicks]

Originally Posted by hightower99

You obviously have never tried that with objective measurement (because your ass is biased) This isn't even close to true in the real world. Go ahead try it with some sort of measuring instrument and tell me the results.

You are incorrectly assuming that the energy needed for a given rate of acceleration is independant of velocity. You are totally wrong there, the faster you go the more energy you need to put into the car just to maintain a constant rate of acceleration.

Next you cannot "feel" torque, what you feel is inertial effects from the acceleration of the car which is caused by power. Torque is instantaneous it doesn't have a time or motion componant. When you add the necessary time componant guess what you get... Yup power!

Tell you what, if torque is what moves things then you should be able to tell me the theoretical minimum torque needed to accelerate a car that weighs 1000kg from 0m/s to 20m/s in 3 seconds. If you can give me an answer I will bow out. Since power is what decides acceleration i CAN tell you exactly what the minimum power needed will be to do this.

look closer I said the petrol kills it later in the rev range where it makes less torque than the diesel but manages to out accelerate it.


You are an idiot! get it through your thick skull that acceleration is highly velocity dependant.

it takes alot more energy to accelerate from 100-120 km/h then it does to accelerate from 0-50km/h... please understand this.

I can explain with math and real world examples why and how power does everything. You are using highly subjective and limited experiances to argue your point.

Please somebody who believes that torque is what accelerates you please post an acceleration graph on top of a torque curve graph that matches perfectly.

BTW: I know that was an impossible request...

Also note that torque is changed by gear ratios. Power is not.
This alone should convince most people.

*sigh*
just read:
http://vettenet.org/torquehp.html

As far as acceleration graphs, take a look at this site:
http://www.auto-ware.com/software/meb/meb50.htm
Notice the G-forces FALLING while the car gets closer to redline, and they are highest when its near the torquey RPMs.

also read:
http://www.welltall.com/ymc/discovery/car/shiftpt.html
http://wahiduddin.net/race/dynotest.htm

[Slicks]

Originally Posted by Alastor

Both cars are given an “infinite” number of gears, so there really isn’t a gearing advantage for either one.

And the one that revs higher will have a higher final drive ratio.

So are you saying it is fair to measure acceleration of two cars at different road speeds?

I have been talking about using the same car, not two different cars. And its fair to measure how hard the car pulls at X rpms.

Is a 4-speed transmission better than a 6-speed transmission, no. Why use more gears if it doesn’t change peak acceleration in a specific gear? Because more gears allows the engine to operate near the peak power output across a larger range or road speeds.

A 6 speed is superior because it allows for the same amount of torque to the wheels without sacraficing top end.
If the 4 speed and the first 4 gears of the 6 speed were geared the same, a given car would accelerate the same because its putting the same torque to the ground, but with the 6 speed it has 2 extra gears to work with as well. Or you could gear the 6 speed shorter than the 4 speed (so the given car has the same top speed) and the 6 speed will pull harder than the 4 speed because its putting more torque to the ground than the 4 speed.

[hightower99]

Originally Posted by Slicks

*sigh*
just read:
http://vettenet.org/torquehp.html

As far as acceleration graphs, take a look at this site:
http://www.auto-ware.com/software/meb/meb50.htm

Notice the G-forces FALLING while the car gets closer to redline, and they are highest when its near the torquey RPMs.

also read:
http://www.welltall.com/ymc/discovery/car/shiftpt.html
http://wahiduddin.net/race/dynotest.htm

Thanks for the laugh I needed that.

The first link is completely without any value as it is simple (and incorrect) conjecture based on biased subjective opinions.

No proof at all is supplied.

The link to the graphs goes to a forbidden link so nothing there either.

The last two links you posted are slightly better as both include actual math (gasp!) although there are several dubious faults in the first of the two.

Note also that both of them do not prove that torque moves you or that it is the deciding factor in acceleration. Note that in both examples there equations are actually based on the power made to determine acceleration.

Try reading them and actually understanding the math.

It seems a simple peace of logic is slipping your mind:

In order to prove your theory you need to show that torque is the only factor that decides the rate of acceleration. You cannot do this as the actual velocity you are traveling at determines how hard it is to continue accelerating. So basically you are shot down. However there is one last option. Show an example where a car with high power but low torque accelerates slower than a car with higher torque but lower power.

To validate the proof there cannot be any other explaination (other than torque deciding acceleration) as to why the higher power car accelerates slower meaning the cars used in the example must be as close to identicle as possible.

I am still waiting for an answer to my simple question...

My answer is simple

Car mass: 1000kg
start velocity: 0m/s
Final velocity: 20m/s
Delta time: 3 seconds
Assuming constant acceleration: 6.67m/s*s
Kinetic energy at final velocity: 200kJ
Minimum required power: 66.67kW of power.

I am waiting for that minimum torque....

Also I would like to point out that the kick in the pants you get and whether or not it coincides with the peak torque rpm is highly dependant on which gear you are in. In a low gear (ie 1st or 2nd) the car will accelerate fastest at peak power while in the higher gears (5th or 6th) the car accelerates fastest well below the peak torque rpm. It seems in the middle gears (3rd or 4th) that you get close. This is also dependant on where the peak torque is (high revs, low revs) And it goes to prove what I have said that power and velocity decide how fast you accelerate.

[Alastor]

Originally Posted by hightower99

wrong the second car would accelerate at half the rate of the first one at twice the speed. Otherwise you are correct with twice the power it would accelerate faster at any given speed than the first car.

I thought about this some more:

From 0 to 2000 RPM (114Hp) there will be some kinetic energy stored in the vehicle call it KE. From 2000 RPM to 4000 RPM (228 Hp) there will be an additional 3*KE energy stored by the vehicle. The average power from 0 to 2000 RPMs is 57 HP while the average power from 2000 RPM to 4000 RPM is 171 Hp. So the average power from 2000 RPM to 4000 RPM is three times higher allowing the vehicle to maintain the same acceleration at twice the speed.

Originally Posted by Slicks

And the one that revs higher will have a higher final drive ratio.

Even if the final drive ratio were lower on the higher output engine it would still out perform the lower power engine. More power means more work per unit time, period.

Keeping the engine at peak power at any road speed will generate maximum performance.

What you pass off as a “gearing advantage” is the practical application of power as a function of torque and shaft speed. Power is measure of both torque and RPM together, so more power output means more wheel torque from either raw engine torque or more gearning.

Originally Posted by Slicks

I have been talking about using the same car, not two different cars. And its fair to measure how hard the car pulls at X rpms.

One car or not, measuring at acceleration at different RPMs isn’t fair. Different engine speeds implies different road speeds, and it has already been discussed that it energy to maintain acceleration as velocity increases.

[Slicks]

Originally Posted by hightower99

Thanks for the laugh I needed that.

The first link is completely without any value as it is simple (and incorrect) conjecture based on biased subjective opinions.

No proof at all is supplied.

The link to the graphs goes to a forbidden link so nothing there either.

The last two links you posted are slightly better as both include actual math (gasp!) although there are several dubious faults in the first of the two.

Note also that both of them do not prove that torque moves you or that it is the deciding factor in acceleration. Note that in both examples there equations are actually based on the power made to determine acceleration.

Try reading them and actually understanding the math.

It seems a simple peace of logic is slipping your mind:


To validate the proof there cannot be any other explaination (other than torque deciding acceleration) as to why the higher power car accelerates slower meaning the cars used in the example must be as close to identicle as possible.

I am still waiting for an answer to my simple question...

My answer is simple

Car mass: 1000kg
start velocity: 0m/s
Final velocity: 20m/s
Delta time: 3 seconds
Assuming constant acceleration: 6.67m/s*s
Kinetic energy at final velocity: 200kJ
Minimum required power: 66.67kW of power.

I am waiting for that minimum torque....

Also I would like to point out that the kick in the pants you get and whether or not it coincides with the peak torque rpm is highly dependant on which gear you are in. In a low gear (ie 1st or 2nd) the car will accelerate fastest at peak power while in the higher gears (5th or 6th) the car accelerates fastest well below the peak torque rpm. It seems in the middle gears (3rd or 4th) that you get close. This is also dependant on where the peak torque is (high revs, low revs) And it goes to prove what I have said that power and velocity decide how fast you accelerate.

LMFAO... You have clearly never driven a car before... my god...
The links I posted show the g forces of acceleration in gear, meaning how hard the car pulls. And what do you know, they are greatest around peak torque...
YOU said so yourself, torque changes with gears, but power doesnt. Why then, does 1st gear pull harder than 2nd, although power is the same?

In order to prove your theory you need to show that torque is the only factor that decides the rate of acceleration. You cannot do this as the actual velocity you are traveling at determines how hard it is to continue accelerating. So basically you are shot down. However there is one last option. Show an example where a car with high power but low torque accelerates slower than a car with higher torque but lower power.

Either you dont understand what hp and torque is, or your trying to go by peak numbers which is illogical.
more:
http://images.google.com/imgres?imgu...%3Den%26sa%3DN
http://www.mazda6tech.com/index.php?...id=9&Itemid=52

[hightower99]

Originally Posted by Alastor

I thought about this some more:

From 0 to 2000 RPM (114Hp) there will be some kinetic energy stored in the vehicle call it KE. From 2000 RPM to 4000 RPM (228 Hp) there will be an additional 3*KE energy stored by the vehicle. The average power from 0 to 2000 RPMs is 57 HP while the average power from 2000 RPM to 4000 RPM is 171 Hp. So the average power from 2000 RPM to 4000 RPM is three times higher allowing the vehicle to maintain the same acceleration at twice the speed.

You are assuming too much in this calculation. First it is incorrect to assume that an engine can maintain 300lbs-ft. of torque under say 500rpm so the average power available from 500-2000rpm is likely closer to 71.4 hp. The average you got for 4000rpm is correct (171) so the engine puts in 2.4 times the kinetic energy between 2000-4000rpm then it does between 500-2000rpm this means that between 2000-4000rpm it will accelerate on average 90.5% as fast as it did between 500-2000rpm because it requires 4 times the KE to double velocity. In the real world where you have actual gear ratios this would not be true as the final velocity change between 2000 and 4000rpm could be anything from doubling velocity to only going 10% faster, so again acceleration is dependant on both power and speed (just like in every physics book out there).

Originally Posted by Alastor

Even if the final drive ratio were lower on the higher output engine it would still out perform the lower power engine. More power means more work per unit time, period.

not neccessarily gears basically change the possible ratio between acceleration and top speed (hence the common misunderstanding that acceleration is solely based on torque and top speed on power). So if the gear ratios are different that has a major effect on acceleration just like velocity does. However you where initially correct in saying that if two cars where given a CVT and they had the respective engine speeds locked at 2000 and 4000 then the one with double the power will accelerate twice as fast for any given speed. The ratios will only be slightly out of sync so the idea is valid.

Originally Posted by Alastor

Keeping the engine at peak power at any road speed will generate maximum performance.

Absolutely 100% correct

Originally Posted by Alastor

What you pass off as a “gearing advantage” is the practical application of power as a function of torque and shaft speed. Power is measure of both torque and RPM together, so more power output means more wheel torque from either raw engine torque or more gearning.

Again absolutely 100% correct!

Originally Posted by Alastor

One car or not, measuring at acceleration at different RPMs isn’t fair. Different engine speeds implies different road speeds, and it has already been discussed that it energy to maintain acceleration as velocity increases.

hmm comparing acceleration at different RPMs isnt unfair as long as the start velcities are the same.

Originally Posted by Slicks

LMFAO... You have clearly never driven a car before... my god...

I would like to know where you got that silly idea from? I would bet that not only have I driven but that I am a better driver than you.

Originally Posted by Slicks

The links I posted show the g forces of acceleration in gear, meaning how hard the car pulls. And what do you know, they are greatest around peak torque...

You are wrong why don't you actually look at them. You will find that not only does max acceleration almost never happen exactly where peak torque is (disproving your theory) but that the G curve matches perfectly if you calculate one with power vs. speed.

I find it hilarious that everything you have posted links to happens to disprove your own theory and support mine fully. Note that in this new batch you can quote "Interesting note: You will always get your fastest acceleration by shifting AFTER the horsepower peak (unless you have a CVT, in which case you will have the fastest acceleration by keeping the engine AT the horsepower peak)."

Originally Posted by Slicks

YOU said so yourself, torque changes with gears, but power doesnt. Why then, does 1st gear pull harder than 2nd, although power is the same?

You must be joking... right?

You cant for the life of you describe why first gear accelerates faster than 2nd even when the power is the same? (without saying it is based on torque?)

You are sadly lacking in intelligence... anyways the simple answer is that gears act as a ratio modifier basically between top speed and acceleration. Understand it like this: the lower the gear the less velocity change there is from idle to redline in that gear. Do you see where I am going with this yet?

1st gear simply has less velocity change between idle and redline than 2nd gear and that means that the same power can accelerate the car more quickly. Basically you should think of gears as a means to stretch out the velocity attainable over the engines operational speed range (that would be from idle to red line rpm).

Let me know if you didn't understand that.

BTW slicks: I know exactly what power and torque is...

It seems you don't

[Alastor]

Originally Posted by hightower99

You are assuming too much in this calculation. First it is incorrect to assume that an engine can maintain 300lbs-ft. of torque under say 500rpm so the average power available from 500-2000rpm is likely closer to 71.4 hp. The average you got for 4000rpm is correct (171) so the engine puts in 2.4 times the kinetic energy between 2000-4000rpm then it does between 500-2000rpm this means that between 2000-4000rpm it will accelerate on average 90.5% as fast as it did between 500-2000rpm because it requires 4 times the KE to double velocity.

I was given two data points, engine output at 2,000 RPM and 4,000 RPM, the only assumption I made was that both the power and torque outputs were zero at 0 RPM. IMO this is a safe assumption, I don’t think it is practical to try to predict the nonlinear behavior of a hypothetical engine given two or three co-linear points. It also makes the point less clear with unnecessary over complication.

Originally Posted by hightower99

In the real world where you have actual gear ratios this would not be true as the final velocity change between 2000 and 4000rpm could be anything from doubling velocity to only going 10% faster, so again acceleration is dependant on both power and speed (just like in every physics book out there).

That is certainly valid for operating in several gears, but so far the discussion has be focused on engine speed change in a single gear.

Originally Posted by hightower99

not neccessarily gears basically change the possible ratio between acceleration and top speed (hence the common misunderstanding that acceleration is solely based on torque and top speed on power). So if the gear ratios are different that has a major effect on acceleration just like velocity does. However you where initially correct in saying that if two cars where given a CVT and they had the respective engine speeds locked at 2000 and 4000 then the one with double the power will accelerate twice as fast for any given speed. The ratios will only be slightly out of sync so the idea is valid.

In the case stated the engine running at 4,000 RPM will have an effective gear ratio twice that of the 2,000 RPM engine at any given road speed which is certainly significant. I just wanted to make it clear that the increase in gearing is possible because of the increase in power, but an increase in gearing was not required for the higher power output engine to perform better.

Originally Posted by hightower99

hmm comparing acceleration at different RPMs isnt unfair as long as the start velcities are the same.

But is unfair for a single vehicle in a single gear, because different RPM have to occur at different road speeds.

[henk4]

Originally Posted by hightower99

What makes you think that? it would be in a higher gear and it would have dropped down in the rev range to where it makes roughly 60hp...

yes, but it makes its top torque there....and that determines accelaration. Power determines how far/fast you can get...and torque how fast you can get there.....

[hightower99]

Originally Posted by Alastor

I was given two data points, engine output at 2,000 RPM and 4,000 RPM, the only assumption I made was that both the power and torque outputs were zero at 0 RPM. IMO this is a safe assumption, I don’t think it is practical to try to predict the nonlinear behavior of a hypothetical engine given two or three co-linear points. It also makes the point less clear with unnecessary over complication.

Just my opinion but to me your example was over simplified and led to an answer that isn't really "in the ball park" or real results. The idea and how you went about it where great... just the details that where left behind.

Originally Posted by henk4

yes, but it makes its top torque there....and that determines accelaration. Power determines how far/fast you can get...and torque how fast you can get there.....

Look Torque does not determine acceleration.

Power and you velocity change does!

How can power (which is a derivitive of torque) determine only certain factors and torque alone can determine others? The statement has a total lack of logic.

Torque is a static, abstract force (note the static part, you can't feel torque). You can only measure it when you are standing still. As soon as you move torque becomes power as it obtains a time and motion componant.

This is grade school physics really I was expecting better.

You are wrong and further unwillingness to admit your fault is nothing but ignorance mixed with a dash of arrogance.

[henk4]

Originally Posted by hightower99

How can power (which is a derivitive of torque) determine only certain factors and torque alone can determine others? The statement has a total lack of logic.

dixit

[hightower99]

Originally Posted by henk4

dixit

I never said torque had nothing to do with power now did I?

I said torque doesn't determine acceleration

Power does...

[henk4]

Originally Posted by hightower99

I never said torque had nothing to do with power now did I?

I said torque doesn't determine acceleration

Power does...

when power is a derivative, torque is at the basis, isn't it?

[jediali]

Originally Posted by hightower99

You are wrong and further unwillingness to admit your fault is nothing but ignorance mixed with a dash of arrogance.

Hightower I respect your technical determination, and i think your a star but:

1) show members such as Henk4 with respect, regardless of right/wrongness. Henk4 is more than a pretty face () and was made to react argumentatively by your "i'm right, your wrong" approach to posting.
2) your ideas of physics are sort of construed. I dont want to pick points (unless you ask me to, then i will provide concisive engineering evidence against you)....I would say torque is tangible when engine accelerates. Power, which is a rate is ultimately intangible?!?!..Either you are very unclear/confused typer or my Meng degree is useless

[hightower99]

Originally Posted by henk4

when power is a derivative, torque is at the basis, isn't it?

yes meaning that torque doesn't determine acceleration on it's own as there are other factors needed (a time componant for starters).

Originally Posted by Jediali

Hightower I respect your technical determination, and i think your a star but:

1) show members such as Henk4 with respect, regardless of right/wrongness. Henk4 is more than a pretty face and was made to react argumentatively by your "i'm right, your wrong" approach to posting.

I have shown respect but he continues... I respect him enough to let him tell me if he thinks I am being harsh.

Originally Posted by Jediali

2) your ideas of physics are sort of construed. I dont want to pick points (unless you ask me to, then i will provide concisive engineering evidence against you)....I would say torque is tangible when engine accelerates. Power, which is a rate is ultimately intangible?!?!..Either you are very unclear/confused typer or my Meng degree is useless

I do type the odd typo here and there but:

Torque is static and can't be felt (if you think so please provide an example)
Power is simply the rate at which you can do work. You can feel when work is being done, right? You have an internal sense of time and so you can feel the difference between work that is done fast (like putting your hand on a hot stove top) as opposed to work being done slowly (like putting your hand on a massive tank of slightly warm water).

Your MechEng degree is not useless and you have shown yourself to be intelligent and logical however that doesn't mean that you are impervious to making mistakes niether does it make you all-knowing. I have met many people with a high level of relevant education who are confused about this very topic.

Also if you could point out the points that you disagree with and why you disagree with them I would appreciate it as I do want to learn all I can about this subject.

[Slicks]

Originally Posted by hightower99

I would like to know where you got that silly idea from? I would bet that not only have I driven but that I am a better driver than you.

Because your logic is way off, if you have driven a car before, you would have noticed that it accelerates on the torque curve.
If what your saying is true, and a car accelerates according to the hp curve, then it would be very noticable how hard a car pulls at 2000RPMs, opposed to say 6000RPMS where hp would be trippled(lets assume a flat torque curve from 2000-6000RPMs). The car would pull three times harder, thats what your saying right? Wouldnt that be VERY noticable?

You are wrong why don't you actually look at them. You will find that not only does max acceleration almost never happen exactly where peak torque is (disproving your theory) but that the G curve matches perfectly if you calculate one with power vs. speed.

Did YOU actually look at them? Am I going to have to spoon feed you this one?
Lets start here:
http://www.wahiduddin.net/race/dynotest.htm
Now actually LOOK at the graphs. Do you agree that G forces are a fair measure for how hard the car is accelerating?
Lets take a look at the rear wheel thrust (torque) graph compared to the g-forces in acceleratoin graph, do you not see a direct relation? Do you want me to draw it out for you?

I find it hilarious that everything you have posted links to happens to disprove your own theory and support mine fully. Note that in this new batch you can quote "Interesting note: You will always get your fastest acceleration by shifting AFTER the horsepower peak (unless you have a CVT, in which case you will have the fastest acceleration by keeping the engine AT the horsepower peak)."

Highlight EXACTLY what proves me wrong from my links.
You get the fastest acceleration at (or after) the hp peak because your running each gear ratio out to its fullest speed, providing more wheel torque than if you were to switch to the next gear sooner.

You must be joking... right?

You cant for the life of you describe why first gear accelerates faster than 2nd even when the power is the same? (without saying it is based on torque?)

You are sadly lacking in intelligence... anyways the simple answer is that gears act as a ratio modifier basically between top speed and acceleration. Understand it like this: the lower the gear the less velocity change there is from idle to redline in that gear. Do you see where I am going with this yet?

1st gear simply has less velocity change between idle and redline than 2nd gear and that means that the same power can accelerate the car more quickly. Basically you should think of gears as a means to stretch out the velocity attainable over the engines operational speed range (that would be from idle to red line rpm).

Let me know if you didn't understand that.

BTW slicks: I know exactly what power and torque is...

It seems you don't

Sorry but that makes no sense.
PLEASE find me ANY article or proof that a car accelerates on its hp curve. Find a graph like you said you would.