Lexus: Horsepower vs. Torque
09-19-12, 04:04 PM
#31
Disprove, no but there are big downsides that lead us to not having a ton of super high revving engines in everything.
The bigger and heavier a thing you have to move the more you value TQ. That's one of the reasons why container ships don't have super high revving engines with complex gearboxes. You start reaching technical limits on piston speeds and the number of G's the pistons have to endure when reversing stroke, etc... and that's in normal cars never mind larger things.
The bigger and heavier a thing you have to move the more you value TQ. That's one of the reasons why container ships don't have super high revving engines with complex gearboxes. You start reaching technical limits on piston speeds and the number of G's the pistons have to endure when reversing stroke, etc... and that's in normal cars never mind larger things.
09-19-12, 04:58 PM
#32
Power is a function of torque and RPM. You can't have power without torque. Engines create torque first and foremost, not power. If we ever become able to build diesels that can achieve, say, 6000 RPM, you can say goodbye to the gasoline engine as the performance choice.
Anyways, this article is terrible. Ship engines don't have torque? Whatever editor approved this needs to be sent to physics 101.
Anyways, this article is terrible. Ship engines don't have torque? Whatever editor approved this needs to be sent to physics 101.
Diesel engines have been used very successfully in Le Mans racing for many years now.
09-19-12, 05:27 PM
#33
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http://en.wikipedia.org/wiki/Audi_R10_TDI
Diesel engines have been used very successfully in Le Mans racing for many years now.
Diesel engines have been used very successfully in Le Mans racing for many years now.
look at Le Mans regulation:
gasoline racing engines limited to 3.4 liters normally aspirated
gasoline racing engines limited to 2.0 liters turbocharged
Diesel racing engines limited to 3.7 liters turbocharged (and allows much higher boost than gas)
if Diesel cannot win giving those HUGE advantage, i don't know what can they do?
09-19-12, 10:10 PM
#34
Pole Position
^^^^^^
Don't look now but Toyota just played by Audi's rule and beat Audi using a PETROL-hybrid engine :
https://www.clublexus.com/forums/car...in-brazil.html
Don't look now but Toyota just played by Audi's rule and beat Audi using a PETROL-hybrid engine :
https://www.clublexus.com/forums/car...in-brazil.html
Last edited by natnut; 09-20-12 at 12:33 AM.
09-19-12, 11:27 PM
#35
IMHO, Le Mans is the biggest scam ever paid by Audi.
look at Le Mans regulation:
gasoline racing engines limited to 3.4 liters normally aspirated
gasoline racing engines limited to 2.0 liters turbocharged
Diesel racing engines limited to 3.7 liters turbocharged (and allows much higher boost than gas)
if Diesel cannot win giving those HUGE advantage, i don't know what can they do?
look at Le Mans regulation:
gasoline racing engines limited to 3.4 liters normally aspirated
gasoline racing engines limited to 2.0 liters turbocharged
Diesel racing engines limited to 3.7 liters turbocharged (and allows much higher boost than gas)
if Diesel cannot win giving those HUGE advantage, i don't know what can they do?
09-20-12, 09:30 AM
#36
Jeez. So much misinformation in the OP. This Hubbard guy would do well to take some basic mechanical engineering courses; he sounds like an idiot.
“You know, a lot of people buy horsepower, when what they really want is torque,” Hubbard told me. “Torque is what gets you to the speed you want quickly; horsepower is what keeps you there.”
This is as bad as that stupid VW ad from years ago. Torque on its own does NOTHING for you. It is a static value. Velocity, acceleration, and jerk are all based on changes over a period of time and so torque doesn't mean much of anything here. It's like comparing blank pages and a novel.
No wonder Lexus and Toyota make slow cars if they got buffoons like this guy in charge. Get out of the way and let the engineers do the work.
“You know, a lot of people buy horsepower, when what they really want is torque,” Hubbard told me. “Torque is what gets you to the speed you want quickly; horsepower is what keeps you there.”
This is as bad as that stupid VW ad from years ago. Torque on its own does NOTHING for you. It is a static value. Velocity, acceleration, and jerk are all based on changes over a period of time and so torque doesn't mean much of anything here. It's like comparing blank pages and a novel.
No wonder Lexus and Toyota make slow cars if they got buffoons like this guy in charge. Get out of the way and let the engineers do the work.
09-20-12, 07:59 PM
#37
Lexus Champion
Jeez. So much misinformation in the OP. This Hubbard guy would do well to take some basic mechanical engineering courses; he sounds like an idiot.
“You know, a lot of people buy horsepower, when what they really want is torque,” Hubbard told me. “Torque is what gets you to the speed you want quickly; horsepower is what keeps you there.”
This is as bad as that stupid VW ad from years ago. Torque on its own does NOTHING for you. It is a static value. [
] Velocity, acceleration, and jerk are all based on changes over a period of time and so torque doesn't mean much of anything here. It's like comparing blank pages and a novel.
No wonder Lexus and Toyota make slow cars if they got buffoons like this guy in charge. Get out of the way and let the engineers do the work.
“You know, a lot of people buy horsepower, when what they really want is torque,” Hubbard told me. “Torque is what gets you to the speed you want quickly; horsepower is what keeps you there.”
This is as bad as that stupid VW ad from years ago. Torque on its own does NOTHING for you. It is a static value. [
] Velocity, acceleration, and jerk are all based on changes over a period of time and so torque doesn't mean much of anything here. It's like comparing blank pages and a novel.No wonder Lexus and Toyota make slow cars if they got buffoons like this guy in charge. Get out of the way and let the engineers do the work.
It seems someone else does not know what they are talking about. What do you mean that torque is a static value? Torque is related to acceleration and the greater the torque (until your tires lose grip due to too much torque), the greater the acceleration.
Velocity (speed) is the steady state when there is NO acceleration. Velocity is dependent upon power.
So, “Torque is what gets you to the speed you want quickly; horsepower is what keeps you there” is correct.
09-20-12, 08:16 PM
#38
It seems someone else does not know what they are talking about. What do you mean that torque is a static value? Torque is related to acceleration and the greater the torque (until your tires lose grip due to too much torque), the greater the acceleration.
Velocity (speed) is the steady state when there is NO acceleration. Velocity is dependent upon power.
So, “Torque is what gets you to the speed you want quickly; horsepower is what keeps you there” is correct.
Power (in this case, horsepower) is a function of torque and speed.
the calculation is easy, torque = (5252 x HP) / RPM
The key is torque applied to the ground and for how long that torque can be applied. That is the reason high HP cars are generally faster than high TQ cars... for a motor to have higher torque than HP, that means its usable powerband will generally be between 1500 and 4500 rpm. A motor with higher horsepower generally has a much wider powerband, generally from 3000 rpm to basically as high as you want to spin it, 8000 rpm or more...
No matter what, HP and Torque will ALWAYS be the exact same at 5252 RPM. That is because 5252 is the number used in the math, and the relation between HP and Torque is the equation above...
09-21-12, 07:39 AM
#40
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It seems someone else does not know what they are talking about. What do you mean that torque is a static value? Torque is related to acceleration and the greater the torque (until your tires lose grip due to too much torque), the greater the acceleration.
Velocity (speed) is the steady state when there is NO acceleration. Velocity is dependent upon power.
So, “Torque is what gets you to the speed you want quickly; horsepower is what keeps you there” is correct.
09-21-12, 07:46 AM
#41
Lexus Champion
09-21-12, 09:37 AM
#42
Amazing discussion.
Depending upon engine design, torque can either be
1. Constant across the rpm band
2. Increasing as the rpm increases
3. Decreasing as the rpm increases
4. bumpy across the rpm band
But in any case, Horsepower is dependent upon the torque value at that given rpm.
But the fact that Horsepower is a result of Torque and RPM at that given instant, you have the possibility of increasing horsepower as the rpm increases, even if the torque is rolling down.
It is like more horses pulling the car, as opposed to one.
The power of one is the torque, and the more horses are added with the same power, is seen as increasing horsepower.
gah!
Depending upon engine design, torque can either be
1. Constant across the rpm band
2. Increasing as the rpm increases
3. Decreasing as the rpm increases
4. bumpy across the rpm band
But in any case, Horsepower is dependent upon the torque value at that given rpm.
But the fact that Horsepower is a result of Torque and RPM at that given instant, you have the possibility of increasing horsepower as the rpm increases, even if the torque is rolling down.
It is like more horses pulling the car, as opposed to one.
The power of one is the torque, and the more horses are added with the same power, is seen as increasing horsepower.
gah!
Last edited by chikoo; 09-21-12 at 09:41 AM.
09-21-12, 11:56 AM
#43
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i guess the misunderstanding is from whether it is wheel torque or engine torque.
from the wheel point of view.
E= torque X angle moved. as you can see, to move faster or reach higher speed, you need more Energy.
and engine of the car provides torque at a giving RPM, which is the energy, and its unit is HP (or watt). the torque of the engine at certain RPM has little meaning because it will be re covered by shift gears. the wheel torque can be manipulated by gearing. However, something you cannot manipulate is energy because conservation of energy (unless you bring in quantum physic). that is, giving a fix amount of energy, you can have more torque, or rotate faster. if you want more torque and rotate faster? get more energy.
of course, the feeling of acceleration is actually over a period of time, which is Work (N). and work is a integration of energy over time. to speak from engine point of view, it is the HP produced over a period. this period just happens to be when engine revs from low to high, and since HP is a product of Rev and Torque, one could also say it is a torque curve. . However, the fact stays: more HP gives your more wheel torque at the certain wheel speed. most car has torque curve rather flat, so a torque value gives your a idea of how much "push" you can feel. ( while HP will increase in linear as engine RPM goes higher, you won't feel that because your car is also rotating at higher speed so your 'feel' stay the same).
technically, you could throw the entire "torque curve" out of the window if you car has electric engines. ideally, your engine will be producing constant (HP) and the CVT should cover that to speed or wheel torque. if you look at some electric bus, there is no "torque curve", it is a straight line.
with CVT, the torque curve on the ICE car is actually a lot less meaningful. take maxima for example. when you push it, the engine stays at a constant RPM (where maxim HP is produced), your car accelerate by the change of ratio in CVT. the torque curve of the VQ35 engine, in this case, is entirely useless, the car can have 20 lb ft of torque from 1500 to 5000 for all i care, and it will be just as fast as long as the maximum HP is the same. (well, that is if we hold the break and release the car when engine reaches desired RPM)
anyways. a 1000 HP car with 200 lb ft of torque engine, if driving and geared property, will beat 1000 lb ft of torque but 200 HP engine all day everyday.
if you have different opinion, say it scientifically instead of " i am an engineer". as a fellow engineer and Master in engineering degree, i thought you know better.
from the wheel point of view.
E= torque X angle moved. as you can see, to move faster or reach higher speed, you need more Energy.
and engine of the car provides torque at a giving RPM, which is the energy, and its unit is HP (or watt). the torque of the engine at certain RPM has little meaning because it will be re covered by shift gears. the wheel torque can be manipulated by gearing. However, something you cannot manipulate is energy because conservation of energy (unless you bring in quantum physic). that is, giving a fix amount of energy, you can have more torque, or rotate faster. if you want more torque and rotate faster? get more energy.
of course, the feeling of acceleration is actually over a period of time, which is Work (N). and work is a integration of energy over time. to speak from engine point of view, it is the HP produced over a period. this period just happens to be when engine revs from low to high, and since HP is a product of Rev and Torque, one could also say it is a torque curve. . However, the fact stays: more HP gives your more wheel torque at the certain wheel speed. most car has torque curve rather flat, so a torque value gives your a idea of how much "push" you can feel. ( while HP will increase in linear as engine RPM goes higher, you won't feel that because your car is also rotating at higher speed so your 'feel' stay the same).
technically, you could throw the entire "torque curve" out of the window if you car has electric engines. ideally, your engine will be producing constant (HP) and the CVT should cover that to speed or wheel torque. if you look at some electric bus, there is no "torque curve", it is a straight line.
with CVT, the torque curve on the ICE car is actually a lot less meaningful. take maxima for example. when you push it, the engine stays at a constant RPM (where maxim HP is produced), your car accelerate by the change of ratio in CVT. the torque curve of the VQ35 engine, in this case, is entirely useless, the car can have 20 lb ft of torque from 1500 to 5000 for all i care, and it will be just as fast as long as the maximum HP is the same. (well, that is if we hold the break and release the car when engine reaches desired RPM)
anyways. a 1000 HP car with 200 lb ft of torque engine, if driving and geared property, will beat 1000 lb ft of torque but 200 HP engine all day everyday.
if you have different opinion, say it scientifically instead of " i am an engineer". as a fellow engineer and Master in engineering degree, i thought you know better.
Last edited by seanlee; 09-21-12 at 05:30 PM.
09-22-12, 09:45 AM
#45
i guess the misunderstanding is from whether it is wheel torque or engine torque.
from the wheel point of view.
E= torque X angle moved. as you can see, to move faster or reach higher speed, you need more Energy.
and engine of the car provides torque at a giving RPM, which is the energy, and its unit is HP (or watt). the torque of the engine at certain RPM has little meaning because it will be re covered by shift gears. the wheel torque can be manipulated by gearing. However, something you cannot manipulate is energy because conservation of energy (unless you bring in quantum physic). that is, giving a fix amount of energy, you can have more torque, or rotate faster. if you want more torque and rotate faster? get more energy.
of course, the feeling of acceleration is actually over a period of time, which is Work (N). and work is a integration of energy over time. to speak from engine point of view, it is the HP produced over a period. this period just happens to be when engine revs from low to high, and since HP is a product of Rev and Torque, one could also say it is a torque curve. . However, the fact stays: more HP gives your more wheel torque at the certain wheel speed. most car has torque curve rather flat, so a torque value gives your a idea of how much "push" you can feel. ( while HP will increase in linear as engine RPM goes higher, you won't feel that because your car is also rotating at higher speed so your 'feel' stay the same).
technically, you could throw the entire "torque curve" out of the window if you car has electric engines. ideally, your engine will be producing constant (HP) and the CVT should cover that to speed or wheel torque. if you look at some electric bus, there is no "torque curve", it is a straight line.
with CVT, the torque curve on the ICE car is actually a lot less meaningful. take maxima for example. when you push it, the engine stays at a constant RPM (where maxim HP is produced), your car accelerate by the change of ratio in CVT. the torque curve of the VQ35 engine, in this case, is entirely useless, the car can have 20 lb ft of torque from 1500 to 5000 for all i care, and it will be just as fast as long as the maximum HP is the same. (well, that is if we hold the break and release the car when engine reaches desired RPM)
anyways. a 1000 HP car with 200 lb ft of torque engine, if driving and geared property, will beat 1000 lb ft of torque but 200 HP engine all day everyday.
if you have different opinion, say it scientifically instead of " i am an engineer". as a fellow engineer and Master in engineering degree, i thought you know better.
from the wheel point of view.
E= torque X angle moved. as you can see, to move faster or reach higher speed, you need more Energy.
and engine of the car provides torque at a giving RPM, which is the energy, and its unit is HP (or watt). the torque of the engine at certain RPM has little meaning because it will be re covered by shift gears. the wheel torque can be manipulated by gearing. However, something you cannot manipulate is energy because conservation of energy (unless you bring in quantum physic). that is, giving a fix amount of energy, you can have more torque, or rotate faster. if you want more torque and rotate faster? get more energy.
of course, the feeling of acceleration is actually over a period of time, which is Work (N). and work is a integration of energy over time. to speak from engine point of view, it is the HP produced over a period. this period just happens to be when engine revs from low to high, and since HP is a product of Rev and Torque, one could also say it is a torque curve. . However, the fact stays: more HP gives your more wheel torque at the certain wheel speed. most car has torque curve rather flat, so a torque value gives your a idea of how much "push" you can feel. ( while HP will increase in linear as engine RPM goes higher, you won't feel that because your car is also rotating at higher speed so your 'feel' stay the same).
technically, you could throw the entire "torque curve" out of the window if you car has electric engines. ideally, your engine will be producing constant (HP) and the CVT should cover that to speed or wheel torque. if you look at some electric bus, there is no "torque curve", it is a straight line.
with CVT, the torque curve on the ICE car is actually a lot less meaningful. take maxima for example. when you push it, the engine stays at a constant RPM (where maxim HP is produced), your car accelerate by the change of ratio in CVT. the torque curve of the VQ35 engine, in this case, is entirely useless, the car can have 20 lb ft of torque from 1500 to 5000 for all i care, and it will be just as fast as long as the maximum HP is the same. (well, that is if we hold the break and release the car when engine reaches desired RPM)
anyways. a 1000 HP car with 200 lb ft of torque engine, if driving and geared property, will beat 1000 lb ft of torque but 200 HP engine all day everyday.
if you have different opinion, say it scientifically instead of " i am an engineer". as a fellow engineer and Master in engineering degree, i thought you know better.
Also, what I said is only true if these engines weighed the same, were mated to transmissions that were of the same weight, and shifts between gears were instant.