Drive Accord Honda Forums banner

1 - 20 of 44 Posts

·
Registered
Joined
·
56 Posts
Discussion Starter #1
Fair warning: detailed question below for dorks/engineers only, maybe lol.

Been struggling with a pretty complicated issue - trying to figure out when the HAH produces 212 hp.

First some facts about the 2018+ HAH drivetrain (off top of my head, so maybe off slightly):
-ICE engine makes 143hp @ 6200 rpm and 129 lbft torque @ 4000 rpm.
-Motor/generator makes 142.8 hp and 63 lbft torque.
-Propulsion motor makes 181 hp peak, and 232 lbft peak (listed at 6000 rpm, but as has been reported here previously, that's not an rpm that matches engine rpm... it's something like 1/3rd engine... so peak would be the equiv of 2000rpm when the engine is running along with it).

Now for where I'm stuck:
I've figured out a lot of how the HAH works from looking at the First Gen, Second Gen, and Third Gen press releases, each of which humorously divulged either a bit of extra info on how the system works, or ata least makes it possible to infer how it works from presenting incremental improvements or metrics over the previous generation.

But what's still vexxing me is how to summon the 212 total horsepower, which Honda refers to at one point as the "total peak concurrent output of the 2 motors and engine".

By that wording, they're not doing fuzzy math - some driving condition is allowing the engine and at least one of the motors to work together.

Figuring that out from the documentation and press releases is really tricky though.

At one point, a situation is described in one of the press releases, I think the 2nd gen (2017) where it says at high speeds, the engine runs via the clutch. And it can be supplemented by the propulsion motor, like during rapid acceleration needs. But, the problem is when I'm in the car, driving at, say 55mph, and I'm in part-throttle, I do see the engine working, the clutch icon, and the propulsion motor helping a bit (presumably to prevent lugging). However, if I floor it, weirdly, the gear icon disappears as the car starts to accelerate rapidly. Which suggests the engine is just generating now as it revs up, and I'm only getting accelerated by the 181 peak hp propulsion motor.

So I'm theorizing Honda is being a bit coy either in their graphics of what's happening on the center screen... or some part of the hybrid system is able to offer short bursts of power that exceed the quoted specs they've listed.

Their description of the new "Sport Mode" in 2017 hints at such - saying it allows the battery to feed the propulsion motor more than the 2014 car.

Lastly, there's possibly some funny business going on with the motor-generator that I (and Honda) have us thinking only generates electricity. I'm positing it has some temporary ability to act as a secondary propulsion motor or similar, given the fact it a) apparently can spool up the engine to burn off energy at times, and b) crank the engine to get it started up and rev-matched to current speeds when taking over from EV mode. So it can clearly either generate or provide power at times.

So again, does anyone else sharper or more informed than myself know what driving situation is allowing access to the full 212 hp, and which of the 3 power sources are contributing?

And for the record, my guesses are it's one of the below:
1) Either from a hard launch from stop, the propulsion motor is providing more than the 181 peak hp quoted, via some electronic equivalent to how some cars have "overboost".
2) At higher speeds only (so not a hard launch), when the car's alreaady in hybrid mode, the engine revs to max, and either the motor-generator and propulsion motors are BOTH working together to provide more power than the propulsion motor could alone.
3) At higher speeds only (so not a hard launch), when flooring the car, the gear icon disappearing is not accurate, and there's either intentional further engine power being allowed to the ground via intentional clutchslip, or it's staying locked up, and is supplemented by the propulsion motor.
4) Something else I totally haven't thought of?
 

·
Registered
Joined
·
339 Posts
This question has also puzzled me, basically for the reasons you outline.

When cruising down the freeway, at 70 mph, say, the gas engine is "helping" propel the car. But, the gas engine is at a fairly low rpm, more or less similar to what you have in a gas-engine-only car. I am guessing somewhere in the 2,000 to (at most) 2500 rpm range. At that rpm, the hp from the gas engine is only going to be 40-50 hp (as a rough estimate). And since the total power needed simply to maintain cruising speed is not that much, the main traction electric motor is probably not contributing much.

However, and as noted above, if you step on the gas to accelerate, the gas engine uncouples from the driving wheels, so that the gas engine can rev up, in order to provide additional electric power to the main traction motor, which is stated to be 180-ish hp.

It is not obvious to me that there is any "real world" driving condition under which 212 combined hp is actually being used, at least not at "normal" freeway speeds or below....

One possible scenario for actually using the combined 212 hp is if you were driving at sustained speeds that were well above the legal limit. If you gently accelerate from 70 mph, and keep going faster and faster (but without accelerating very quickly), then perhaps the gas engine stays coupled, and, as the speed (and the gas engine's rpm) increases, you will be getting more power out of the gas engine. I can imagine some high speed where the gas engine might be providing 70 or 80 hp (or even more), but in order to overcome wind resistance, there is also a non-trivial power contribution from the main traction motor.

But it still seems to me that at legal freeway speeds, there might not be any way to get (or use) the combined hp rating..... (Fundamentally due to the fact that there is essentially only one "gear" for the gas engine, when it is coupled to the driving wheels.)

As a side comment, the same 212 combined hp figure is quoted for the Clarity plug-in hybrid, which uses the same traction electric motor, but has a lower hp 1.5 liter gas engine......
 

·
Registered
Joined
·
56 Posts
Discussion Starter #3
^Ok that is weird - and you're right. The Clarity plugin with the smaller 1.5L does show BOTH the same peak hp, and peak torque (212/232). Now this is getting strange.
 

·
Registered
Joined
·
327 Posts
In an electric motor, where I is the current and k is some constant, TRQ=k*I.

The wiring in an electric motor will begin to melt if you pass too much current through it. So a motor is rated for its maximum current, Imax. The torque rating of a motor is thus k*Imax. The Accord and Clarity use the same motor, where k*Imax=232.2 lb=ft.

But there is also a limit to the power the motor can take over a sustained period. This same motor is limited to a maximum sustained power of 181 hp. Since physics says HP = TRQ*RPM/5252, these are the resulting torque and power curves for this motor:
517959

The prevailing opinion, which I have no basis to accept or reject, is that the same motor can tolerate a little more power for brief periods. So it can go up to 212 HP.

Since the motor can reach this point as long as the ICE and battery can supply the power. That's why the Clarity has the same ratings as the Accord.
 

·
Registered
Joined
·
56 Posts
Discussion Starter #5
The Accord and Clarity use the same motor, where k*Imax=282.2 lb=ft.
Did you mean 232.2 lb=ft? That's the figure I've seen... not the 282. But aside from that it makes sense.

So are you thinking there's an overboost type feature that comes into play if you a) click Sport Mode and b) floor it from a dead stop? And that 212hp power comes in if you're c) near full battery charge, and then some X seconds later, as you keep it floored, 212 hp tapers down to 181 hp?

That could be. Anyways, here's an interesting dyno from the Gen 1 HAH (2014) that, while using weaker motors and engine, seems to hint at such a feature. Notice how the power crescendos around 35mph, then slowly tapers off. Maybe you've seen it already, but if not, pretty interesting. In that 2014 car, the peak motor power SHOULD be 166 hp, but the dyno shows it getting 176 AT THE WHEEL at peak, and then slowly coming back down. And Honda claimed 196 hp combined on the 2014. So 196hp - 10% drivetrain loss = ~176 hp, so that matches up.

 

·
Registered
Joined
·
327 Posts
Did you mean 232.2 lb=ft? That's the figure I've seen... not the 282. But aside from that it makes sense.
Yep - was working from memory, and just misplaced the digit. They both have two rounded parts stacked on top of each other, and both appear frequently in the HAH and the Camry hybrid stsyems, which I compare it to a lot. I'll see if I can fix it.

So are you thinking there's an overboost type feature that comes into play if you a) click Sport Mode and b) floor it from a dead stop? And that 212hp power comes in if you're c) near full battery charge, and then some X seconds later, as you keep it floored, 212 hp tapers down to 181 hp?
I have no idea how - or even if - it can happen. I raised the point in a Clarity forum, and after I (well, almost) got them to admit there was a confusing issue since the cars had the same combined horsepower with the same motor but different engines, this is what they said.

+++++

Unrelated anecdote: I am probably mildly dyslexic (I intentionally left a typo in the above explanation) (Dyslexics Of The World, Untie!). But I grew up in the 60s and 70s, before the condition was well known, learning to compensate.

Back in the day, my employer (a very large HOCO one you can probably remember) changed from a mid-1900s phone system to a late 1900s phone system. One of the great features of the new one was that when employees changed offices, they could take their phone extension with them. Unfortunately, I changed offices during the shake-down period when this feature was disabled. So I went from building-office number 1-173 to 1-179, and changed extensions from x7119 to x7199 (and much later in my career, to 17-117, with x7199). And between the 21 digits in my home phone, my cell phone, and my wife's cell, there were twelve 3s or 7s. Since that move, I haven't been very reliable at remembering any of these numbers, and confuse digits far more than I used to.
 

·
Registered
Joined
·
56 Posts
Discussion Starter #7
Haha. That's unfortunate... maybe? But not if you solved it with a workaround!

Yeah, it seems odd with the HAH, that they'd keep that kind of magic sauce secret. Doesn't make a ton of sense, because you'd think Toyota or anyone really interested would just buy 1-2 HAHs, dissect them, and run them through all kinds of testing and data logging and figure it out anyway. Regardless, it would be interesting to know what conditions are required to access that 212hp figure temporarily.

From my butt-dyno, I suspect it's accessible when the battery is nearly full (when I've floored it at different speeds, the consistent feeling I note is that if the battery is at or within 2 notches of full, it pulls harder than if the battery level starts lower).
 

·
Registered
2020 Accord Hybrid EX-L
Joined
·
128 Posts
I tend to believe the 212hp/158kW happens on the 181hp driving motor.
Consider these points:
  1. 2.0 NA engine has a max 105kW, which matches the generator motor max of ~105kW. The remaining 53kW? From the battery.
  2. Electric motor is easier to overclock than ICE, as long as overheating is controlled. Since it is rated at 135kW @5000~6000 rpm (which as @JeffJo commented should be engine rpm) and logically can steadily work under this power, short-term overclocking by 17% is fully acceptable. Note that Toyota hybrids and many full EVs now also hide their motor specs, which I think is to avoid causing concern if average people don't believe electric motors are more capable of overclocking than ICEs.
  3. I am seriously mean short-term. Considering some conversion loss, let's assume the battery must provide 60kW to accomplish total 158kW. Since it is only a 1.35 kWh battery pack and the system always wants to reserve 20% remaining capacity, this discharging can happen for a max of 1.35 kW × 80% × 3600 s ÷ 60 kW = 65 s. In real life situations, it would be less than 65 s because a) the battery isn't always full and b) the battery can overheat under high current but it is only passively air cooled.
In real life conditions, 65 s of 212hp boost is probably sufficient for most drivers. Though, mpg would look terrible when a 2.0NA ICE is frequently working at 6200 rpm. Another flaw is that total output degrade dramatically to 143hp (possibly times 95% for converting loss to electricity) after the battery depletes itself; now, this is only 71% of the 1.5T max output, which means 1.5T can provide better passing on freeway.

When I took a road trip to Corning NY via the mountainous NY-17 highway last weekend, the disadvantages of my hybrid are really amplified...I recorded mid 30s mpg at 75-85mph cruising, but suffered a lot by the limited power on long uphill climbing.

Note that this Li-ion battery is different from what is used in full EVs. Those tend to focus more on energy density but charging/discharging rate is moderate. Non-plug hybrids like Honda and Toyota use another group of Li-ion batteries which allow very high discharging rate, but their energy density is much lower.
 

·
Registered
Joined
·
21 Posts
I tend to believe the 212hp/158kW happens on the 181hp driving motor.
Consider these points:
  1. 2.0 NA engine has a max 105kW, which matches the generator motor max of ~105kW. The remaining 53kW? From the battery.
  2. Electric motor is easier to overclock than ICE, as long as overheating is controlled. Since it is rated at 135kW @5000~6000 rpm (which as @JeffJo commented should be engine rpm) and logically can steadily work under this power, short-term overclocking by 17% is fully acceptable. Note that Toyota hybrids and many full EVs now also hide their motor specs, which I think is to avoid causing concern if average people don't believe electric motors are more capable of overclocking than ICEs.
  3. I am seriously mean short-term. Considering some conversion loss, let's assume the battery must provide 60kW to accomplish total 158kW. Since it is only a 1.35 kWh battery pack and the system always wants to reserve 20% remaining capacity, this discharging can happen for a max of 1.35 kW × 80% × 3600 s ÷ 60 kW = 65 s. In real life situations, it would be less than 65 s because a) the battery isn't always full and b) the battery can overheat under high current but it is only passively air cooled.
In real life conditions, 65 s of 212hp boost is probably sufficient for most drivers. Though, mpg would look terrible when a 2.0NA ICE is frequently working at 6200 rpm. Another flaw is that total output degrade dramatically to 143hp (possibly times 95% for converting loss to electricity) after the battery depletes itself; now, this is only 71% of the 1.5T max output, which means 1.5T can provide better passing on freeway.

When I took a road trip to Corning NY via the mountainous NY-17 highway last weekend, the disadvantages of my hybrid are really amplified...I recorded mid 30s mpg at 75-85mph cruising, but suffered a lot by the limited power on long uphill climbing.

Note that this Li-ion battery is different from what is used in full EVs. Those tend to focus more on energy density but charging/discharging rate is moderate. Non-plug hybrids like Honda and Toyota use another group of Li-ion batteries which allow very high discharging rate, but their energy density is much lower.
Hi Ziyang, I am curious your experience with limited power on long uphill climbing. What is this compared with? 1.5t or 2.0t?
The reason I ask is I am debating between 1.5t and 2.0 hybrid, and if the limited power issue is compared with with 1.5t, then I might shift my target to 1.5t. thanks!
 

·
Registered
Joined
·
327 Posts
The power rating of an ICE car is really a rating of the motor only. At just one rpm, and just one throttle setting, it makes that much power. When driving the car, you will likely only pass through that rpm while accelerating, and probably not at the right throttle. Then there are losses that reduce what power is applied to the road. It's useful for comparison to other ICEVs, but not between ICEVs and HEVs.

Since my last post, I've heard some things about the HAH from people who heard it from people who, well, know but are trying hard not to say. The gist seems to be that 212 hp is not intended to mean power applied to the road. It is power generated by the power-generating systems in the car. It is not associated with any particular speed of the car, and in fact the HAH can only ever apply 181 HP to the road. But it can do so at any speed above about 42 mph.
 

·
Registered
2020 Accord Hybrid EX-L
Joined
·
128 Posts
Hi Ziyang, I am curious your experience with limited power on long uphill climbing. What is this compared with? 1.5t or 2.0t?
The reason I ask is I am debating between 1.5t and 2.0 hybrid, and if the limited power issue is compared with with 1.5t, then I might shift my target to 1.5t. thanks!
I’m really disappointed with this limited uphill climbing power. I bet it is worse than 1.5T, needless to say 2.0T.

I recall my previous 2017 Civic 1.5T+MT had much better driving ability at 80 mph uphill. Its 6th gear could climb every freeway hill I encountered because of the assisted turbo. When I wanted more power, downshifting to 4th gear always made me satisfied.

As I said before, when the battery is depleted, your max system power is only 70% of the 1.5T. This is really a big flaw of Honda’s hybrid system.

What’s your daily driving environment? If freeway uphill is rarely encountered, hybrid is still peppier than 1.5T in most cases. Plus, you gain the smoothest near-EV driving feel.
 

·
Registered
Joined
·
422 Posts
Since Horsepower is a "derived" value, it's really kind of meaningless as far as I'm concerned. A more meaningful value is Torque, which is NOT "derived". Also, I wonder if Honda's value of 212 Hp is "Mechanical" Horsepower equivalent to almost 746 Watts, or, is it the smaller "Metric" Horsepower, equivalent to almost 736 Watts?

But, since Hp depends on both Torque and Speed, often when one of these is high, the other is low.

- Jack
 

·
Registered
2020 Accord Hybrid EX-L
Joined
·
128 Posts
Since Horsepower is a "derived" value, it's really kind of meaningless as far as I'm concerned. A more meaningful value is Torque, which is NOT "derived".
This is incorrect.

Torque is meaningless without power. With a 1/2" drive breaker bar I can easily apply 150 lb·ft of torque which is more than the max of accord hybrid 2.0L engine can provide. Does this mean I am more powerful than a 2.0NA engine???

Power determines the ability to provide energy, and is far more important than torque. Hitting the throttle means asking for kinetic energy and your system power now determines how fast the car can gain kinetic energy, or, accelerate from 65mph to 85mph to pass someone on freeway. Going uphill means asking for gravitational energy. Cruising at horizontal freeway means compensating for air/rolling friction energy loss.

Torque? That's where the transmission plays for regular ICE at starting speed. Of course, electric motor shines for providing max torque at 0rpm, but for freeway passing the limiting factor is not torque anymore but the max power our hybrid system can provide.

But, since Hp depends on both Torque and Speed, often when one of these is high, the other is low.
No. You first have the system power then torque and rpm is related i.e.
power = torque × rpm.
The higher power a motor is rated, the higher rpm it can work at max rated torque. After max torque × rpm is greater than max power, or, you are at a certain speed, it has to work under constant-power mode, and the torque decreases with increasing speed from this point.
 

·
Registered
Joined
·
21 Posts
I’m really disappointed with this limited uphill climbing power. I bet it is worse than 1.5T, needless to say 2.0T.

I recall my previous 2017 Civic 1.5T+MT had much better driving ability at 80 mph uphill. Its 6th gear could climb every freeway hill I encountered because of the assisted turbo. When I wanted more power, downshifting to 4th gear always made me satisfied.

As I said before, when the battery is depleted, your max system power is only 70% of the 1.5T. This is really a big flaw of Honda’s hybrid system.

What’s your daily driving environment? If freeway uphill is rarely encountered, hybrid is still peppier than 1.5T in most cases. Plus, you gain the smoothest near-EV driving feel.
Thanks for the reply. One question I have is if the hybrid is consistently at 65mph+, wouldn't the battery be mostly full because it is always being charged?

The reason I ask is I had a old Nissan Altima hybrid a few years ago, and whenever I have long trip on highway (50mph+) then the battery is always close to full because it keeps charging the battery.

I often have to drive between NY and Boston for about 250 miles one way. Generally the highway is flat but there is about 20 miles of highway that is uphills so I just want to see if Accord hybrid is sufficient.

My previous car was a 9th gen 2.4 Accord, and I think the car is driving well in terms of power and gas. I had a few times that the trip computer shows 40mpg across the whole 250-mile trip
 

·
Registered
Joined
·
422 Posts
Sorry, Ziyang, but you're not quite right. As you correctly stated, Hp = Tq x RPM. Now consider: what happens if Torque does not drop off as speed increases? Well, this would imply you could simply go faster and faster, maybe even reach light speed! Wow! But, this never happens.

So, there's some speed, where you simply cannot go any faster - you've been limited by the available torque. Torque is the force your engine generates to make you move.

And, you bet! You, with a suitable breaker bar can generate far more torque than our engines can put out. This torque might be enough to move a locomotive if applied correctly. What's the old saying, something like: "Give me a lever long enough and I can move the world?". But, the engine in one of our Accords would not move that locomotive, not without a serious set of gears - it would just stall. With the breaker bar you have, you could probably easily stall the engine in an Accord.

Unless something moves, there is no work, so no power.

You stated: "The higher power a motor is rated, the higher rpm it can work at max rated torque." This is also incorrect. You should have said, "...it can work at a GIVEN torque". If the torque is reduced, the power is also reduced. And, yes, if the speed is reduced, at a given torque, the power is also reduced.

This is what I meant by saying Power is a "derived" value, it is dependent on both torque and speed. You won't get that speed without sufficient torque.

- Jack
 

·
Registered
2020 Accord Hybrid EX-L
Joined
·
128 Posts
Thanks for the reply. One question I have is if the hybrid is consistently at 65mph+, wouldn't the battery be mostly full because it is always being charged?

The reason I ask is I had a old Nissan Altima hybrid a few years ago, and whenever I have long trip on highway (50mph+) then the battery is always close to full because it keeps charging the battery.

I often have to drive between NY and Boston for about 250 miles one way. Generally the highway is flat but there is about 20 miles of highway that is uphills so I just want to see if Accord hybrid is sufficient.

My previous car was a 9th gen 2.4 Accord, and I think the car is driving well in terms of power and gas. I had a few times that the trip computer shows 40mpg across the whole 250-mile trip
Thanks for asking.

The answer is no. Below ~72mph the hybrid system will keep between 20% and 40% charge on acc. It will run on full EV shortly from 40% to 20%, then connect engine to drive as well as slightly charge the battery.

Above 72mph, in most cases engine is directly connected, and battery remains ~50% charge. It can assist uphill climbing. During downhill cruise it may shut off the engine if power is not needed, and charge the battery gradually.

I never see it fully charged unless really long down hill; in contrast, above 80mph it gets depleted so frequently because any small uphill is calling battery assistance.

I am aware of NY-Boston routes. I think it can easily handle I-84 hill, but if you take CT-15 the hybrid driving experience is worse than 1.5T—I do this every week.

If highway makes >80% of your mileage I’d suggest 1.5T or 2.0T. ICE works quite efficiently at freeway condition, and you have so much more reserved power to pass others or simply have fun.
 

·
Registered
2020 Accord Hybrid EX-L
Joined
·
128 Posts
Sorry, Ziyang, but you're not quite right. As you correctly stated, Hp = Tq x RPM. Now consider: what happens if Torque does not drop off as speed increases? Well, this would imply you could simply go faster and faster, maybe even reach light speed! Wow! But, this never happens.

So, there's some speed, where you simply cannot go any faster - you've been limited by the available torque. Torque is the force your engine generates to make you move.

And, you bet! You, with a suitable breaker bar can generate far more torque than our engines can put out. This torque might be enough to move a locomotive if applied correctly. What's the old saying, something like: "Give me a lever long enough and I can move the world?". But, the engine in one of our Accords would not move that locomotive, not without a serious set of gears - it would just stall. With the breaker bar you have, you could probably easily stall the engine in an Accord.

Unless something moves, there is no work, so no power.

You stated: "The higher power a motor is rated, the higher rpm it can work at max rated torque." This is also incorrect. You should have said, "...it can work at a GIVEN torque". If the torque is reduced, the power is also reduced. And, yes, if the speed is reduced, at a given torque, the power is also reduced.

This is what I meant by saying Power is a "derived" value, it is dependent on both torque and speed. You won't get that speed without sufficient torque.

- Jack
Your reply is full of flaws. I feel you are messing up force-based analysis and energy-based analysis, which makes the discussion hard to continue.

Power is NEVER a ‘derived’ value; it is designed by engineers at the beginning of developing an engine, as well as the torque. When discussing accelerating ability at higher speeds, most people tend to compare max power at a quite high rpm; the purpose of transmission is to help make engine work close to such rpm for any speed. That’s when you get the BEST acceleration, although it’s not the max torque rpm. Does this make sense?

When people talk about why Bugatti Chiron has max speed of 430 km/h, they credit this to the max 1100kW power from the engine, not the 1600Nm max torque. However, nobody denies that such a wide-range torque plateau offers good acceleration within a wide speed range.

Your torque theory is poorly limited to ICE but energy-based analysis applies to all kinds of engine. Now how would you apply torque to a jet engine? It works by pushing air to the rear, not rotating. It’s rated power easily implies how fast a plane can go.

Sure you can make everything logical using this force-based system, but when it comes to discussing the limited acceleration of Accord hybrid above 75mph, energy-based analysis, or power, is much easier to make things clear than your torque theory.

Why is hybrid less peppy than 1.5T after battery is depleted? Simply because it’s max power output of a 2.0NA is weaker than that of a 1.5T! Why bothering details like torque, rpm etc? You just don’t have the ability to gain energy!

A lever long enough only helps you understand physics, but helps nothing in making me more powerful than a 2.0NA engine. Please avoid making ‘infinite’ things into real world comparison.
 

·
Registered
Joined
·
327 Posts
Sorry, Ziyang, but you're not quite right. As you correctly stated, Hp = Tq x RPM. Now consider: what happens if Torque does not drop off as speed increases? Well, this would imply you could simply go faster and faster, maybe even reach light speed! Wow! But, this never happens
Oddly, the last sentence is right. This never happens. The ironic thing is that you meant it to apply to "you could simply go faster and faster," but what it actually applies to is "torque does not drop off as speed increases."

But if the impossible became possible - and wheel force was able to remain constant regardless of speed, I won't try to describe how - there would be no paradox as you claim. Momentum, not speed, would continue to increase linearly, forever. This is possible since relativistic mass would increase, while observed velocity would approach the speed of light asymptotically.

This is what I meant by saying Power is a "derived" value, it is dependent on both torque and speed.
And you are wrong.

Power, torque, and rpms are interrelated by the identity P=k*T*RPM. Each represents a different, measureable quantity in Physics.Given any two of them, the other can be "derived."

What you are trying to describe is a causal relationship - that torque on the driveshaft "causes" power in the system, but that this power does not "cause" the torque. But that is a naive description. It is the power released by burning gasoline that causes pressure in the cylinders to increase, which in turn causes a force on the pistons, which is what creates torque on the crankshaft. So torque is "derived" from power. You won't get torque without sufficient power driving it. But this "derived" is meaningless.
 

·
Registered
Joined
·
19 Posts
This thread is like Big Bang Theory without any of the jokes.
Seriously, you guys remind me of how dumb I really am.
Cool to know there are guys like you guys out there helping move our species forward.
Peace.
 

·
Registered
2020 Accord Hybrid EX-L
Joined
·
128 Posts
Oddly, the last sentence is right. This never happens. The ironic thing is that you meant it to apply to "you could simply go faster and faster," but what it actually applies to is "torque does not drop off as speed increases."

But if the impossible became possible - and wheel force was able to remain constant regardless of speed, I won't try to describe how - there would be no paradox as you claim. Momentum, not speed, would continue to increase linearly, forever. This is possible since relativistic mass would increase, while observed velocity would approach the speed of light asymptotically.


And you are wrong.

Power, torque, and rpms are interrelated by the identity P=k*T*RPM. Each represents a different, measureable quantity in Physics.Given any two of them, the other can be "derived."

What you are trying to describe is a causal relationship - that torque on the driveshaft "causes" power in the system, but that this power does not "cause" the torque. But that is a naive description. It is the power released by burning gasoline that causes pressure in the cylinders to increase, which in turn causes a force on the pistons, which is what creates torque on the crankshaft. So torque is "derived" from power. You won't get torque without sufficient power driving it. But this "derived" is meaningless.
I’m happy to see your comprehensive disagreement against @jackpine here.

While I don’t agree his saying that power is somewhat a derived term, you make a better rebuttal from how things are interrelated from the bottom.
 
1 - 20 of 44 Posts
Top