Rb30 Patrol

[nicksamaniac]

So where does the power go?

Or are going to stick to the theory there is no power loss?

Am I wrong in believing there is no such thing as drive train loss's?

If I had held my engine at full song for long enough would it have made 90hp instead of 75?

I don't belive it could have, it would of continued to reach redline, or if we increased load at the rollers to hold it from reaching redline hp would drop as it would overcome the power the engine had to reach that speed.

I said before, the only way to achieve the same reading with the same engine via different drive lines is at static speed, and when you maintain a speed, the torque and hp drop to point, they level out, and speed becomes constant.

There is no way to maintain a speed and achieve the same readings through different drive lines.

its like saying a 150amp alt at full load wont cause a loss more than a 50amp alt at full load? That 100amp has gota be made somewhere? And to produce it the engine works that bit more to make it.

[GTSBoy]

its like saying a 150amp alt at full load wont cause a loss more than a 50amp alt at full load? That 100amp has gota be made somewhere? And to produce it the engine works that bit more to make it.

No, it's not like that at all. If you're extracting 1.2kW from the big alternator then of course you'd see a difference over extracting 400W from the small alternator. And not only that, but we can see how the power is being extracted and where it is going (ie, into whatever electrical load you're running).

A big, heavy tailshaft spinning at 5000rpm cannot lose ANY power, no matter how much power it is transferring, compared to a smaller tailshaft. There is nothing in the tailshaft (save a few needle roller bearings) where power can turn into heat.

YES.....you must measure at steady state to eliminate inertial effects. YES, inertial effects may make it FEEL as if power is being lost, but no actual power is being lost. if you can show me where the heat comes out of your heavy component system, then I will grant you that power is being lost. As it is not possible for you to do so, I will not.

Edited October 10, 2014 by GTSBoy

[nicksamaniac]

Again im not talking about static losses, I am talking about dynamic losses, rotational windage, inertial acceleration, these are whats measured in the REAL WORLD not in an engineering lab at a car designer workshop.

I understand you explaining conversion of engergy, I understand it very well.

But you have not yet explained drive train loss through wieght difference?

As it FEELS like a power loss? Well thats becouse there IS a loss, through dynamic means, inertial reaction.

Heat ONLY comes from friction through transfer of energy, either from convection, physical friction or radiation, they are ALL transfer of PHYSICAL energy,from large components all the way down to friction of electrons even down to light particles or the atomic level.

But not dynamic energy, this does not transfer to heat unless there is interfering parts, it a measurement of acceleration over time.

So if I had an r33,rb25 that made exactly 200.0kw atw on 17" rims, 245/45r17 tires.

Then took that exact engine out and put into my patrol and managed to fit the same rims/tires on it for the dyno (no loss through tire/rim size)

It will still make 200.0kw at the wheels? With absolutely no losses?

for where the heat goes, through the radiator to atmosphere, as load increases, more power is demanded, more heat is generated, radiator works abit more, the world keeps turning, universe keeps expanding, entropy never takes place, and so on.

Edited October 10, 2014 by nicksamaniac

[nicksamaniac]

And a big heavy drive shaft WILL loose power through static loss.

If a shaft A- 500mm long 80mm dia, and 5kg will take X power and torque to maintain a static speed.

Then shaft B- 3000mm long 350mm dia, and 40kg will require Y power to maintain the same speed, there is absolutely no way it can maintain the same speed as drive shaft A at the same power and torque.

[GTSBoy]

And a big heavy drive shaft WILL loose power through static loss.

If a shaft A- 500mm long 80mm dia, and 5kg will take X power and torque to maintain a static speed.

Then shaft B- 3000mm long 350mm dia, and 40kg will require Y power to maintain the same speed, there is absolutely no way it can maintain the same speed as drive shaft A at the same power and torque.

You are so absolutely wrong about that. Conservation of angular momentum, conservation of energy are both physical laws that beg to differ. The first says that a rotating object will continue to do so unless acted on by an outside force. Set both your shafts spinning, give them both the same kinetic energy and the same bearing losses, and they will decelerate at the same rate. (actually, they will possibly decelerate at slightly different rates unless you happened to match the polar moments of inertia also). Give them the same bearing losses and spin them up to the same speed and the big one will decelerate at a decreased rate and spin on for longer simply because it has more energy captured in it at the start.

Anyway, my explanation just then is surplus to the requirement to say that you are wrong about needing different amounts of power to keep those two shafts spinning. You are wrong. Look up Newton's first law.

And just to finish off, per your previous post.....if you do not convert the energy into heat then it is not lost. If you trap it as kinetic energy in the drivetrain it is not lost. It may slow your ramp, but IT IS NOT A LOSS.

Edited October 10, 2014 by GTSBoy

[nicksamaniac]

So to my question on the 2 different cars and same engine?

And no I am not wrong, it will require more power to be accelerated up to speed, as there will ALWAYS be external influence becouse we dont operate cars on a stand in the vacume of space away from any gravity source.

There is always 99.999% of the time a load of sorts. And the shafts of different sizes will have different bearings, larger yolks, different angles at the joints.

Again there is always influence to play a part in the way it works.

In the end, you can dictate physics in a perfect environment with zero outside influence to a point where the differences play little to no part.

But here on earth, where there will always be some affect by the parts we use in a drive line, there will be losses due to size, shape, materials, wieght, and it will be a measurable difference at the wheels.

Yes your answers are surplus to some things but you have not yet provided a real world example of how there wont be a loss with a larger drive train?

put a 8hp briggs in your car and tell me it still makes 8hp at the treads!

[nicksamaniac]

Or better yet! With all your knowledge you could work for nasa and explain to them they could take 1 months worth of extra fuel, supplies, an extra moon buggy and 6 extra astronauts but only need the same power rocket to reach space as wieght plays no part in power loss!

[GTSBoy]

You have no idea. I stop wasting my time right here.

[nicksamaniac]

Before you go, I still need you to explain my 15hp loss atw when compared to a street version RB30 car?

If I never know the truth behind it I'll be doomed to spend the rest of my life in a world where quantum mechanics are just dont follow conventional rules of thermodynamics!!!!

dooooooooomed!!!!!!!!

[Joshbigt62r]

GTSBoy is correct. He has already explained to you above what you want to know and the anwsers so I wont go into any more detail as its covered. Shakes head!

[nicksamaniac]

Yes I agree with 50% of what hes explained, and is correct from a theoretical point when done in a perfect environment with no outside interference although in practical application, why is there a loss in power, at the wheels, when using a larger drive line?

He said if you spin a shaft up to speed it will remain at said speed untill there is an aposing force, and in REAL life situations, there is ALWAYS an aposing force,

im sorry for winding you up gtsboy, but explaining the way you did is like saying perpetual motion is the real deal!

My original argument is that a larger drive line Will show a loss atw on a dyno, that has yet to be proven to me otherwise?

[R_34]

There will be no power loss, you just used more power to move the heavier reciprocating part at the same ramp speed on the dyno than with smaller counter parts.

You do not lose power, you use it differently. More to move the driveline, less to the wheels BUT if you measure both driveline at a STEADY state you WILL measure the EXACT SAME power.

You "wasted" some energy into kinetic energy because of the higher inertia of the heavier parts.

It's the exact same thing than a lighter flywheel compared to a standard one. You do not gain any power but the engine drives very differently leading you to BELIEVE you gained power. You just removed inertia to overcome when accelerating. This is the exact opposite when decelerating, your heavier driveline will net you a much smaller deceleration ramp rate. This is where you're power has been spent rather than moving wheels. But you still have the same power.

If the dyno reads effectively the deceleration ramp rate of your driveline after a pull it will take into account the higher inertia and it will not reads you a lower rwkw number.

[XKLABA]

Why do you people keep trying to steer this discussion away from what was originally said

Two cars with different driveline components ON A DYNO doing a POWER RUN, so trying to accelerate the drive line components which includes the wheels ( in this particular case one has 33"s and the other has 35"s ) and NOT HOLDING THE SPEED STATIC

So where does the power loss come from WHEN TRYING TO ACCELARATE when doing a power run on a dyno which is the point Nick was making and has been trying to point out since GTSboys first post, which you guys have already answered in your posts when trying to prove Nick wrong, which he isn't as his point is POWER LOSS FROM DRIVELINE COMPOMENETS ACCELERATING ON A DYNO

What GTSboy is saying is right but he is arguing the wrong point

[nicksamaniac]

^^^^finally a person who gets what im asking!!!!

Not 1 person yet has exlpained, without contradiction to themselves, how the same engine on 2 different drive lines will result in different rw readings.

Of course the ramp changes, of course there is angular moment difference, of course there is polar moment difference,

All these kinetic energy and dynamic loss differences WILL show lower readings.

That is because ---there is no way to obtain a static measurement at full rpm, full power and full torque and achieve the same result. No way....

There WILL ALWAYS be variables affecting how things work, its real life, its how the world works, its the truth!

k to my RB25 question? 200.0kw atw in an r33? Same engine in a patrol, same wheels to remove that variable! How will it ever make 200.0kw at the wheel then?

It won't, it can't and it never will!

Say there is 2 cars, both the same car but 1 has a beefed up race spec hd drive line, both have 300hp Engines,

both cars cruising at 50km/hr on flat road, 1 car uses 40hp to maintain the speed due to wind drag, rolling resistance etc, the 2nd car (big driveline) uses 50hp to maintain that same speed for the same reasons plus the fact that it has extra wieght in the drive,

Oh but that wont effect it you say?

Yes it will and heres why?

It wieghs more, giving it more rolling resistance, the stored kinetic energy is f#ck all compared to the resistance it will have at cruising speed.

This is why you loose a rear wheel reading figure.

Edited October 10, 2014 by nicksamaniac

[steve200b]