View Poll Results: Who won the debate: MK (HP) or VR (Torque)
Mk won with a simple to understand concept that HP determines torque at the wheels at any speed.
25
17.48%
MK won: When comparing equal HP cars, the one with less torque COULD be better on the road course.
6
4.20%
VR won: When comparing equal HP cars, the one with more torque is better on a road course.
44
30.77%
Neither, as physics dont apply to race cars
18
12.59%
I don't want to open this can of worms again!
50
34.97%
Voters: 143. You may not vote on this poll
Poll: Who won the HP vs Torque debate?
03-19-2009, 12:10 PM
#286
Rennlist Member
Thread Starter
Your equation is off. Please correct . Then, let me know if it all makes sense. based on your argument below, it is clear how you cant "Swollow " the truth.
Doesn't your argument now entail
A = (Torque X 5252) / (RPM x m x V), so torque does matter.
care to correct it?
anyway, it is the logitudinal force that is put to the ground. this is regardless of engine torque as a value. its still needed as a fundamental factor, but it can be at values all inversely proportional to RPM (engine speed). In otherwords, acceleration is independent of the engine's torque value, and dependent on the engine's HP value at any vehicle speed when doing the comparison we speak about in this discussion.
mk
Doesn't your argument now entail
A = (Torque X 5252) / (RPM x m x V), so torque does matter.
care to correct it?
anyway, it is the logitudinal force that is put to the ground. this is regardless of engine torque as a value. its still needed as a fundamental factor, but it can be at values all inversely proportional to RPM (engine speed). In otherwords, acceleration is independent of the engine's torque value, and dependent on the engine's HP value at any vehicle speed when doing the comparison we speak about in this discussion.
mk
Good god I hate to feed this monster.
I'm now calling 30 pages. But I can't swallow Mark's conclusion that its a simple answer and only horsepower matters. Horsepower is calculated though from torque so its not independent
Mark your argument seems to be that since
A = P / (m X V)
power is the only thing that matters.
Now since
P = (Torque X 5252) / RPM
Doesn't your argument now entail
A = (Torque X 5252) / (RPM x m x V), so torque does matter.
I just can't get past the fact that we're trying to put it in simple terms. Its not that simple and there is a lot that has to be considered to create a vehicle that has a certain performance. The argument that two vehicles of exact same spec except engine numbers is flawed. It is not possible to have two vehicles in which the only variable is the hp/torque numbers and expect everything else to still be equal. In the end the only thing that matters is the longitudinal force that the tires are putting to the ground.
I'm now calling 30 pages. But I can't swallow Mark's conclusion that its a simple answer and only horsepower matters. Horsepower is calculated though from torque so its not independentMark your argument seems to be that since
A = P / (m X V)
power is the only thing that matters.
Now since
P = (Torque X 5252) / RPM
Doesn't your argument now entail
A = (Torque X 5252) / (RPM x m x V), so torque does matter.
I just can't get past the fact that we're trying to put it in simple terms. Its not that simple and there is a lot that has to be considered to create a vehicle that has a certain performance. The argument that two vehicles of exact same spec except engine numbers is flawed. It is not possible to have two vehicles in which the only variable is the hp/torque numbers and expect everything else to still be equal. In the end the only thing that matters is the longitudinal force that the tires are putting to the ground.
Last edited by mark kibort; 03-19-2009 at 12:33 PM.
03-19-2009, 12:11 PM
#287
Rennlist Member
Twenty pages, on the way to thirty!
38
29
Professional Racing and Driving Coach
38
29
Professional Racing and Driving Coach
03-19-2009, 12:16 PM
#288
Burning Brakes
Join Date: Oct 2004
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Not exactly. Watts is a measure of power. 746watts equal 1 hp.
future of racing will not be direct drive motors. constant torque is not an advange of an electric power plant. the advantages are a very wide HP cuve.
Even an electic DC/AC servo motor has a power curve. to maximize acceleration, you have to maximize power (or watts). To do this the race car of the future will employ a infinitely variable gear box. Meaning, upon max acceleration request, the motor will ONLY operate at max HP or Watts.
mk
future of racing will not be direct drive motors. constant torque is not an advange of an electric power plant. the advantages are a very wide HP cuve.
Even an electic DC/AC servo motor has a power curve. to maximize acceleration, you have to maximize power (or watts). To do this the race car of the future will employ a infinitely variable gear box. Meaning, upon max acceleration request, the motor will ONLY operate at max HP or Watts.
mk
Any kind of transmission (other than a straight gearing) will only be additional weight and something to blow up at the high RPMs that are possible.
The biggest issue at this point is the power source for the motors... battery technology isn't quite there yet.
And the ability to start from a stop and just put your foot down and accelerate all the way to top speed, without having to shift or otherwise be out of power or create instability in the car, will be HUGE.
Mind you, I'm just a computer engineer, so I may not properly understand how this applies to high-school physics and an overly-simplified race car model.
03-19-2009, 12:29 PM
#290
Rennlist Member
Thread Starter
It wont matter, as power, is torque AND speed. So no matter what they can produce, the high rpms will always produce more power than the low power rpms. A IVT will be able to handle the loads, thats a mecanical thing, just as the CV joints and other moving components handle the forces.
Such electronics are good for, "Push to pass" type of performance with single speed gear boxes, they are not as efficient as an infinitely variable gear box in utalizing avaiable power.
Im sure there will be some hybrid of the two technologies when it hits main stream racing.
In "Reality" there is an electric performance car. it has one gear box. (they tried a two speed gear box, but it had failures). great on the street, but weak from 80mph to its top speed of 125mph due to the points ive mentioned.
What do I know, i was only an top exec for one of the leading motion control companies in the world for 12 years, specializing in electric propulsion, transmissions and their control.
mk
Such electronics are good for, "Push to pass" type of performance with single speed gear boxes, they are not as efficient as an infinitely variable gear box in utalizing avaiable power.
Im sure there will be some hybrid of the two technologies when it hits main stream racing.
In "Reality" there is an electric performance car. it has one gear box. (they tried a two speed gear box, but it had failures). great on the street, but weak from 80mph to its top speed of 125mph due to the points ive mentioned.
What do I know, i was only an top exec for one of the leading motion control companies in the world for 12 years, specializing in electric propulsion, transmissions and their control.
mk
Uhmmm... you might want to go and read up on ongoing development of transformer circuit topologies, especially synchronous wound-rotor doubly-fed designs and their effects on core saturation. Current technologies allow for torque bursts 10 times the operational torque values.
Any kind of transmission (other than a straight gearing) will only be additional weight and something to blow up at the high RPMs that are possible.
The biggest issue at this point is the power source for the motors... battery technology isn't quite there yet.
And the ability to start from a stop and just put your foot down and accelerate all the way to top speed, without having to shift or otherwise be out of power or create instability in the car, will be HUGE.
Mind you, I'm just a computer engineer, so I may not properly understand how this applies to high-school physics and an overly-simplified race car model.
Any kind of transmission (other than a straight gearing) will only be additional weight and something to blow up at the high RPMs that are possible.
The biggest issue at this point is the power source for the motors... battery technology isn't quite there yet.
And the ability to start from a stop and just put your foot down and accelerate all the way to top speed, without having to shift or otherwise be out of power or create instability in the car, will be HUGE.
Mind you, I'm just a computer engineer, so I may not properly understand how this applies to high-school physics and an overly-simplified race car model.
03-19-2009, 12:31 PM
#291
Rennlist Member
..
03-19-2009, 12:31 PM
#292
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
As usual, Markie has gone from mildly entertaining with his Rainman impressions to dull and boring at this point.
03-19-2009, 12:38 PM
#293
Rennlist Member
Ah, you continue to believe your flawed assumption that all of those who didn't pick #1 or #2 in your self-serving, ridiculous poll, are "followers" of VR (or anyone for that matter), "don't understand physics", etc. It must be very comfortable for you when you hide in your little Theater of The Mind!
As usual, Markie has gone from mildly entertaining with his Rainman impressions to dull and boring at this point.
As usual, Markie has gone from mildly entertaining with his Rainman impressions to dull and boring at this point.
Professional Racing and Driving Coach
03-19-2009, 12:45 PM
#294
Rennlist Member
Thread Starter
Again Bull, its not my interpretation, its Newtons. There is no "flawed assumption". Its simple, power at any speed, out of a turn or otherwise, determines rate of acceleration. No one , but one has challenged this, and they were missing a key component of their equation. When they fix it, it will all make sense to him. the others??? Havent heard.
Bottom line, there is a a dependent factor when deciding whether a high torque engine vs low torque engine, with the same HP is better for a road course. That is the HP curve. It CAN favor a lower torque engine, that is ALL we are debating here. I showed a clear, irrefutable example of this.
Again, im just the messenger here, unless I can be proved otherwise.
Im still working on my VR Special theory of acceleration. It will show how he can be right too. stay tuned.
mk
Bottom line, there is a a dependent factor when deciding whether a high torque engine vs low torque engine, with the same HP is better for a road course. That is the HP curve. It CAN favor a lower torque engine, that is ALL we are debating here. I showed a clear, irrefutable example of this.
Again, im just the messenger here, unless I can be proved otherwise.
Im still working on my VR Special theory of acceleration. It will show how he can be right too. stay tuned.
mk
Ah, you continue to believe your flawed assumption that all of those who didn't pick #1 or #2 in your self-serving, ridiculous poll, are "followers" of VR (or anyone for that matter), "don't understand physics", etc. It must be very comfortable for you when you hide in your little Theater of The Mind!
As usual, Markie has gone from mildly entertaining with his Rainman impressions to dull and boring at this point.
As usual, Markie has gone from mildly entertaining with his Rainman impressions to dull and boring at this point.
03-19-2009, 12:45 PM
#295
Three Wheelin'
my point is NOT that torque doesnt matter, but the level of torque found at the rear wheels (accelerative force) is dependant on HP, not the numerical engine torque when comparing to identical vehicles. Remember, the two vehicles being compared are identical. the only change is the drive train (engine and transmission)
Remember, its not that torque doesnt matter, but it is generated from power.
you dont need torque to calculate HP. you can easily find it by finding the rate of change of kinetic energy, because that is what it is. The rate that force does work. (at the rear tires, HP determnes the "Force" at any vehicle speed.)
you dont need torque to calculate HP. you can easily find it by finding the rate of change of kinetic energy, because that is what it is. The rate that force does work. (at the rear tires, HP determnes the "Force" at any vehicle speed.)
03-19-2009, 12:50 PM
#296
Three Wheelin'
Your equation is off. Please correct . Then, let me know if it all makes sense. based on your argument below, it is clear how you cant "Swollow " the truth.
Doesn't your argument now entail
A = (Torque X 5252) / (RPM x m x V), so torque does matter.
care to correct it?
anyway, it is the logitudinal force that is put to the ground. this is regardless of engine torque as a value. its still needed as a fundamental factor, but it can be at values all inversely proportional to RPM (engine speed). In otherwords, acceleration is independent of the engine's torque value, and dependent on the engine's HP value at any vehicle speed when doing the comparison we speak about in this discussion.
mk
Doesn't your argument now entail
A = (Torque X 5252) / (RPM x m x V), so torque does matter.
care to correct it?
anyway, it is the logitudinal force that is put to the ground. this is regardless of engine torque as a value. its still needed as a fundamental factor, but it can be at values all inversely proportional to RPM (engine speed). In otherwords, acceleration is independent of the engine's torque value, and dependent on the engine's HP value at any vehicle speed when doing the comparison we speak about in this discussion.
mk
Sorry may I should clarify but I thought you'd understand.
Torque is wheel torque and RPM is wheel rpm, to correct it from engine values all you need to do is multiply by the total gear reduction.
03-19-2009, 12:52 PM
#297
Rennlist Member
I still have yet to see that one Mark, all your examples have had issues that were quite refutable. Now whether or not you were willing to accept that from myself or any others here, or danced around it, is another topic.
03-19-2009, 01:28 PM
#298
The Penguin King
Rennlist Member
Rennlist Member
It seems to me that there is a simple resolution to this issue that can be summed up in one little word:
IGNORE
IGNORE
03-19-2009, 01:37 PM
#299
Still plays with cars.
Lifetime Rennlist
Member
Guys, I have had just about enough of this thread. Mark, if you'd stop repeating basic physics you'd see what those of us who selected " Don't open this can of worms" knew all along.
You and VR are saying pretty much the same thing. Isn't that a neat little summary without all the graphs, denigration, posturing and veiled insults?
You say that a higher RPM engine with less torque can produce more acceleration. VR says that he prefers a car with more torque since it pulls off the corners better.
You say that an engine with less torque can produce more torque due to RPMs and thew torque multiplication of a gear box. OK, more torque at the driving wheels is more torque. Period. Full stop.
OK now if we all take a deep breath and observe that VR's terse answers did not go into detail, one can interpret Dave's position as "I prefer to drive cars with more rear wheel torque". So whether it is a freaking weed wacker engine with 10 ft/lbs of torque but a red line of 200,000 RPM, there will be a lot of torque at the driving wheels providing a transmission can provide torque multiplication. Doh.
Since I have no skin in this game, I am not out to "WIN" anything. Had this dumb thread been anything but a peeing contest from the outset (winner or loser) we would have saved a lot of server space.
Thank you.
You and VR are saying pretty much the same thing. Isn't that a neat little summary without all the graphs, denigration, posturing and veiled insults?
You say that a higher RPM engine with less torque can produce more acceleration. VR says that he prefers a car with more torque since it pulls off the corners better.
You say that an engine with less torque can produce more torque due to RPMs and thew torque multiplication of a gear box. OK, more torque at the driving wheels is more torque. Period. Full stop.
OK now if we all take a deep breath and observe that VR's terse answers did not go into detail, one can interpret Dave's position as "I prefer to drive cars with more rear wheel torque". So whether it is a freaking weed wacker engine with 10 ft/lbs of torque but a red line of 200,000 RPM, there will be a lot of torque at the driving wheels providing a transmission can provide torque multiplication. Doh.
Since I have no skin in this game, I am not out to "WIN" anything. Had this dumb thread been anything but a peeing contest from the outset (winner or loser) we would have saved a lot of server space.
Thank you.
03-19-2009, 01:42 PM
#300
Rennlist Member
Thread Starter
You are missing the point. what you say below is true. BUT, i dont really understand the argument. do you not agree that two different engines with the same power output, can put down the same torque at any rear wheel speed, or "rpm"??
see my inserts below with the>>>>>>>>>>>>>>>>>>
see my inserts below with the>>>>>>>>>>>>>>>>>>
HP is made of torque and speed. It is directly proportional.
>>>>>>>>>>>>>>>>>>>>>> yes, said this MANY times. there is a trade off right, if rpm goes up, torque goes down proportionally to keep the same HP. And, that is the point and question of the discussion. plug in your equation, keeping power constant, and you can see that very easily, acceleration can be equal by just trading off rpm for torque, for a constant power or power and acceleration at any vehicle speed.
When you put your car on the dyno the MEASURED value is TORQUE and RPM. They then calculate the power. So you're essentially tuning the torque curve to provide the power curve. This torque is the torque output of the rear wheels, but it is very simple to calculate that back to engine torque.
>>>>>>>not nessarily. dont want to get side tracked in symantics, but the dyno really just measures the rate of change of kinetic energy. It doesnt need to know torqe, but that is as easy to find as well. know the mass and diameter, and its rate of speed change and you can find torque (rear wheel, needed to be converted to engine torque, ONLY with an engine RPM value, otherwise the output is just HP and MPH) Otherise, the dyno can show power at any MPH, without calculating engine torque, or even drum torque. If drum torque is needed, it can be calculated as well, but drum speed is needed, so in effect you are seeing that drum torque (rear wheel torque) and power (rate of change in kinetic energy) are related and determine rate of acceleration. of the vehicle, regardless of the engine torque that can be switched "proportionally" for rpm at any time without changing rear wheel forces.
Yes, not the engine torque values but the wheel torque values. But the torque curve at the rear wheels will be identical to the torque at the engine just multiplied by some constant (total gear reduction)
>>>>>>>>>your point is? yes, we know the rear wheel torque will follow the shape of the engine torque, but its value can be infinitly variable at any point, if HP is the same in the comparison.
I think you're looking at it backwards. The engine takes the linear force created in the cylinder and CREATES A TORQUE by spinning the crankshaft. This is the torque output you will see at the flywheel. What reaches the wheels is directly proportional to this due to the gearbox and differential and gives you the torque output at the rear wheels, which directly translates to the longitudinal force applied by the tire.
>>>>>>>>>>no, i think you have it backwards, but again symantics. FUEL is burned, (energy, power, , rate of doing work, HP-seconds, Kw-hours, and other unit measures of work etc) and it determines the force on the pistons at any speed. (i.e power.) again, logitudinal force on the wheel is determined by HP of the engine at any speed, thus proved by the Newton identiy of :
acceleration=power/(mass x velocity) mass being the car, velocity being the speed of the car. The rate of doing work (work is force (or torque) x a distance). You can do this fast or slow. my 7 year old can generate 500ft-lbs of torque, or move my 3000lb car 1/4mile. It mike take him a while, but it can be done. If you want it done quickly, you need power! (a mix of torque and RPM).
>>>>>>>>>>>>>>>>>>>>>> yes, said this MANY times. there is a trade off right, if rpm goes up, torque goes down proportionally to keep the same HP. And, that is the point and question of the discussion. plug in your equation, keeping power constant, and you can see that very easily, acceleration can be equal by just trading off rpm for torque, for a constant power or power and acceleration at any vehicle speed.
When you put your car on the dyno the MEASURED value is TORQUE and RPM. They then calculate the power. So you're essentially tuning the torque curve to provide the power curve. This torque is the torque output of the rear wheels, but it is very simple to calculate that back to engine torque.
>>>>>>>not nessarily. dont want to get side tracked in symantics, but the dyno really just measures the rate of change of kinetic energy. It doesnt need to know torqe, but that is as easy to find as well. know the mass and diameter, and its rate of speed change and you can find torque (rear wheel, needed to be converted to engine torque, ONLY with an engine RPM value, otherwise the output is just HP and MPH) Otherise, the dyno can show power at any MPH, without calculating engine torque, or even drum torque. If drum torque is needed, it can be calculated as well, but drum speed is needed, so in effect you are seeing that drum torque (rear wheel torque) and power (rate of change in kinetic energy) are related and determine rate of acceleration. of the vehicle, regardless of the engine torque that can be switched "proportionally" for rpm at any time without changing rear wheel forces.
Yes, not the engine torque values but the wheel torque values. But the torque curve at the rear wheels will be identical to the torque at the engine just multiplied by some constant (total gear reduction)
>>>>>>>>>your point is? yes, we know the rear wheel torque will follow the shape of the engine torque, but its value can be infinitly variable at any point, if HP is the same in the comparison.
I think you're looking at it backwards. The engine takes the linear force created in the cylinder and CREATES A TORQUE by spinning the crankshaft. This is the torque output you will see at the flywheel. What reaches the wheels is directly proportional to this due to the gearbox and differential and gives you the torque output at the rear wheels, which directly translates to the longitudinal force applied by the tire.
>>>>>>>>>>no, i think you have it backwards, but again symantics. FUEL is burned, (energy, power, , rate of doing work, HP-seconds, Kw-hours, and other unit measures of work etc) and it determines the force on the pistons at any speed. (i.e power.) again, logitudinal force on the wheel is determined by HP of the engine at any speed, thus proved by the Newton identiy of :
acceleration=power/(mass x velocity) mass being the car, velocity being the speed of the car. The rate of doing work (work is force (or torque) x a distance). You can do this fast or slow. my 7 year old can generate 500ft-lbs of torque, or move my 3000lb car 1/4mile. It mike take him a while, but it can be done. If you want it done quickly, you need power! (a mix of torque and RPM).