A work of pure genius! - Brilliant "Revetec" Engine

[revetec]

Answer honestly the following questions Yes or No.

Does increasing Torque at a given RPM increase the power at that RPM?

Does increasing Power increase the work done?

Does increasing Power = Increasing Performance?

Would this increase in power reduce fuel consumption compared with the lesser torque engine which requires to sweep higher volumes per minute to produce that power generally?

[hightower99]

Does increasing Torque at a given RPM increase the power at that RPM?

Yes

Does increasing Power increase the work done?

No, Increasing power increases the rate at which work can be done.

Does increasing Power = Increasing Performance?

Yes

Would this increase in power reduce fuel consumption compared with the lesser torque engine which requires to sweep higher volumes per minute to produce that power generally?

Yes, generally.

My turn, same rules apply (be honest, Yes or No answers):

Does power determine the ratio of torque to speed?

Is a time component/variable included in any definition of torque?

Is a movement component/variable included in any definition of torque?

Can something be dynamic if there is no time or movement component/variable involved?

[revetec]

If it has more power than the given truck engine and proper gearing it will outperform the original truck. It will use significantly more fuel as F1 engines aren't that efficient being designed for maximum specific power as opposed to efficiency.

It will use more fuel. Providing higher torque at lower RPMs is more efficient. This is why we see vehicle transmissions are employing more gears (some around 7 gears these days) Is this to make use of peak power more efficiently? No! It's to keep the RPM lower while driving normally. Lower RPMs means lower fuel consumption as long as the RPM don't drop to far and making the engine labour. Higher torque in lower RPM ranges provides more work or Power.

The goal is to drive around the RPM and load points where engines are most efficient. This isn't around peak power, although higher power is nice when we want to ignore ecomomy.

One thing you must understand is the market used to be about performance, now it is about efficiency and emissions. This is why younger drivers point more importance on Power as people like yourself want Power. The majority of the market look at their running costs and fuel economy.

While Power is important, so is Economy. It's hard these days to increase power without burning more fuel. Burning more fuel usually creates more emissions. Understand that if you provide more torque at lower RPMs then the efficiency increases, especially around 2,000RPM. Our project is all about doing this, as this is what drives the current market.

[hightower99]

Providing higher torque at lower RPMs is more efficient.

Yes as this means there is more power being made while less is being wasted by friction (RPM).

This is why we see vehicle transmissions are employing more gears (some around 7 gears these days) Is this to make use of peak power more efficiently? No! It's to keep the RPM lower while driving normally.

Actually having more gears (up to 8 and counting) means you can maintain lower cruising RPM (reducing friction losses) and maintain higher average power during acceleration which increases performance. So you really get the best of both worlds the more gears you have.

[revetec]

Does power determine the ratio of torque to speed?

No, if I interpreted that question right?

Is a time component/variable included in any definition of torque?

No

Is a movement component/variable included in any definition of torque?

No

Can something be dynamic if there is no time or movement component/variable involved?

No

But by increasing torque, potential energy is increased and can be realised by movement.

[Alastor]

You need torque in the first place to multiply it? If you multiply it too much, you don't have speed.

The emphasis is mine...but you have stated exactly what hightower and I are talking about. You can multiply torque easily with a transmission but at the sacrifice of road speed. An X increase in torque at the wheels means an 1/X decrease in speed at the wheels (i.e. road speed). So there has to be some balance between the torque multiplication and the corresponding speed 'division'.

How does one determine if an engine can produce a good balance of both torque and speed? The answer is power. Power is measure of 'force and velocity'. This can be summarized as:

Low Power = High Torque @ Low Speed or Low Torque @ High Speed
High Power = High Torque @ High Speed

[revetec]

Yes as this means there is more power being made while less is being wasted by friction (RPM).

friction as well as mechanical losses etc. We are looking for efficiency and so is the world.

Actually having more gears (up to 8 and counting) means you can maintain lower cruising RPM (reducing friction losses) and maintain higher average power during acceleration which increases performance. So you really get the best of both worlds the more gears you have.

Yes, and to increase power in Low RPMs when we have close to 100% volumetric efficiency can only be increased significantly by increasing torque or decreasing mechanical losses.

[revetec]

The emphasis is mine...but you have stated exactly what hightower and I are talking about. You can multiply torque easily with a transmission but at the sacrifice of road speed. An X increase in torque at the wheels means an 1/X decrease in speed at the wheels (i.e. road speed). So there has to be some balance between the torque multiplication and the corresponding speed 'division'.

How does one determine if an engine can produce a good balance of both torque and speed? The answer is power. Power is measure of 'force and velocity'. This can be summarized as:

Low Power = High Torque @ Low Speed or Low Torque @ High Speed
High Power = High Torque @ High Speed

And high speed means more fuel burnt and lower efficiency.

Our project is not about increasing power, but increasing efficiency.

[hightower99]

No, if I interpreted that question right?

Ok to help explain the question: A gear ratio in a transmission determines the ratio between input speed and output speed and therefore between input torque and output torque. What determines the ratio between output torque and output speed?

The question was: Does power determine the ratio of (output) torque to (output) speed?

But by increasing torque, potential energy is increased and can be realised by movement.

Not sure I understand what you mean? It must be a bit of a moot point anyways though as you have, through your own honest statements, stated that torque cannot be dynamic.

[Alastor]

And high speed means more fuel burnt and lower efficiency.

Our project is not about increasing power, but increasing efficiency.

I am referring to output shaft speed / wheel speed / road speed not the engine speed. As well, the torque vs power argument is not about efficiency it is about generating the maximum motive force to move the car.

Unless of course the discussion is moving back on topic in which case I will leave this alone.

[hightower99]

Our project is not about increasing power, but increasing efficiency.

By definition increasing efficiency is increasing power per unit fuel per unit time, right?

[revetec]

Ok to help explain the question: A gear ratio in a transmission determines the ratio between input speed and output speed and therefore between input torque and output torque. What determines the ratio between output torque and output speed?

Still a funny question... The ratio decreases speed and increases torque. At what ratio? Well it depends on the gear ratio and the losses of the gears.

The question was: Does power determine the ratio of (output) torque to (output) speed?

No, the transmission does that.

Not sure I understand what you mean? It must be a bit of a moot point anyways though as you have, through your own honest statements, stated that torque cannot be dynamic.

Force isn't dynamic, but the greater the force when used increases the work done.

[revetec]

I am referring to output shaft speed / wheel speed / road speed not the engine speed. As well, the torque vs power argument is not about efficiency it is about generating the maximum motive force to move the car.

Unless of course the discussion is moving back on topic in which case I will leave this alone.

Increasing Power does not relate directly as regards to efficiency.

If we increase the volumetric efficiency of an engine at high RPMs then the power increases, but we use more fuel to do so.

Efficiency can be gained by decreasing mechanical losses such as an innefficient design of transmitting force. Decreasing losses of this type can increase the twisting force we call torque. During operation, this force is converted via RPM to higher work done, or Power, not the other way around.

[Alastor]

The question was: Does power determine the ratio of (output) torque to (output) speed?

No, the transmission does that.

Thats incorect. The transmission (gear ratios) determine the ratio between the input torque and output torque as well as the input speed and output speed. Power determines the ratio between output speed and output torque. It is a subtle but important difference.

Increasing Power does not relate directly as regards to efficiency.

If we increase the volumetric efficiency of an engine at high RPMs then the power increases, but we use more fuel to do so.

Efficiency can be gained by decreasing mechanical losses such as an innefficient design of transmitting force. Decreasing losses of this type can increase the twisting force we call torque. During operation, this force is converted via RPM to higher work done, or Power, not the other way around.

Again you are talking about what is going on at the engine. I am talking about what is going on at the wheels on the output side of the transmission. At that point there is little concern as to if the torque was made efficiently or not, “it is what it is”.

[revetec]

By definition increasing efficiency is increasing power per unit fuel per unit time, right?

I agree, because we are looking at how much fuel to do work.

I will explain something to you.
We have an engine that achieves 207g/(kW-h)
An conventional engine using this design of top end achieves around 320g/(kW-h)
So if this was true, you would agree that the engine uses 2/3s of the fuel to achieve the same work done. ok?
So now put in a vehicle.

Because the torque is higher at lower RPM due to a flatter torque curve (with higher torque at low RPMs) the driving characteristics change.

Due to this we can now drive the engine quite comforable at lower RPMs.

This reduces the amount of RPM we need to accelerate this vehicle due to higher power at lower RPMs.

In vehicle testing we have used less than 2/3s the fuel usage due to exploiting the driving characteristics created by the change in the torque curve.

Now, I do acknowledge what you both are saying. To you both, power is important to you, because it represents work done. Most of your arguements are valid except for not accepting the influence of torque.

When I was younger I had a high performance vehicle. I was not interested in efficiency rather how fast I could complete the quarter mile. My normally aspirated car could get 13.5 seconds on the quarter mile. To me, power was everything. Moving towards my thirties, I was married, I had two children and had quite a tight financial budget. Fuel economy played a big part in me selling this car and opt for a more economical one. At this point I played around with water injection, cams, turbos, manifolds, exhausts as I was still an enthusiast. Bottom line is the majority of people play big importance on fuel economy.

Quite frankly, many of us are not too interested in emissions of our own vehicles as it doesn't effect our financial bottom line. I have heard little of people putting emission reducing devices on their vehicles to reduce only emissions, rather they are chasing better fuel efficiency. The world environment at the moment is a major player in controlling emissions. Governments and regulatory parties drive emission standards tighter that the manufacturers strive to achieve this for the better of our environment.

We have several goals in the industry. Reduce emissions, increase efficiency and seek alternatives to current solutions. None of these include increasing power for our pleasure while disregarding the above stated goals.

Now you both being young like to Push Power, my goal is different as I'm trying to achieve the greatest efficiency I can. This is where we lock heads.

Getting back to my performance car when I was 17yo (1982) my car got 7MPG and the petrol price was AUD$0.32 a litre. I spent AUD$16 to fill my fuel tank which I could easily afford on my AUD$121.00 per week apprentice wage, as I was single and living at home. In less than 30 years the price has increased 500%. Aprentices now earn about AUD$340.00 which is an increase of 180%. Running costs have increased substantially compared to wage price increases.

I think you two should start to think economically as well as being power hungry.