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V8 - V10 Torque


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#1 Ali_G

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Posted 02 April 2006 - 13:40

Would it be right for me to say that considering that the V8 are 2.4L and the V10 are 3.0L that the additional torque for the V10 should be (3.0-2.4)/2.4*100 = 25% extra ?

Now, if this is true, doesn't this really mean that the V10's have a massive advantage as they theoretically have the same horsepower, but they have more torque, therefore more power at low revs ?

And if this is true, anyone want to put money on Tora Rossa for Moanco ? :D

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#2 Stian1979

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Posted 02 April 2006 - 13:53

Lover Hp I gues, but more torque yes.
I dont think the advantage will be there at monaco since the engine manufactures can be ready with there 4 engine upgrade after season start.

If I had to place a bet now I would say renault on 1, Williams on 2 if they can sort out the reabilety problems with there car and Mclaren on 3 and toro rosso on 4

#3 kNt

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Posted 02 April 2006 - 15:16

They are using gearboxes in F1 so it shouldn't be that much of an advantage.

Today in the race onboard a STR car the used rev-band was very slim, just around 15k up to 16.5k and Neel Jani told the television they have an advantage just up to around third gear.

#4 alfa1

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Posted 03 April 2006 - 01:24

Originally posted by Stian1979
Lover Hp I gues, but more torque yes.



Watching the race yesterday from my seat at turn 1, Alonso was braking, slowing to the apex of the corner then LEAPING out of it down the road like the proverbial scalded cat.
I watched to see who else was driving like this. Most everyone else (the McLarens especially) just seemed very smooth but quick. The exception being the STR cars, which were also visibly taking off like rockets.
Maybe Monaco is gonna be really interesting for them.

#5 J. Edlund

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Posted 03 April 2006 - 14:46

Originally posted by Ali_G
Would it be right for me to say that considering that the V8 are 2.4L and the V10 are 3.0L that the additional torque for the V10 should be (3.0-2.4)/2.4*100 = 25% extra ?

Now, if this is true, doesn't this really mean that the V10's have a massive advantage as they theoretically have the same horsepower, but they have more torque, therefore more power at low revs ?

And if this is true, anyone want to put money on Tora Rossa for Moanco ? :D


Torque is by itself not interresting, it doesn't matter if they've got 25% or even 100% more as long the power output is lower. The question is how the powerband is looking, a narrower rpm range like with the V10 engine is usually easier to tune for a flat torque curve. This can give some advantage in power at low speeds when the engine is out of its typical rpm range. But I don't think this doesn't matter that much.

However, the V10 with its lower speeds should have a large advantage when it comes to reliability.

#6 Ali_G

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Posted 03 April 2006 - 18:28

You would expect that V10 to be near bullet proof considering that the revs are being limited.

#7 NTSOS

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Posted 03 April 2006 - 19:49

According to one of the team engineers, some V8's are suffering from an extended duty cycle as compared to the V10's because of their lower power......more time spent per lap at 100% throttle.

John

#8 random

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Posted 04 April 2006 - 10:57

Originally posted by Ali_G
You would expect that V10 to be near bullet proof considering that the revs are being limited.

Agreed. I read an interview suggesting the limited Cosworth V10's could very likely complete 4 or more race distances.

Torque and longevity aren't the only benefits to the rev limited V10's. They also have the advantage of a more usable power band.

The conventional wisdom being that the V8's (being pushed to their limits) only acheive max power at the top of the rev range. Thus making them far more "peaky" than the TR V10's. The V10's wider usable rev range make for a more drivable engine, something especially important in slippery conditions.

It's true the V8's will be more developed by the time they reach Monaco. But one also has to take into consideration the very slippery conditions of the Monaco racing surface. Even without rain, the surface is quite greasy. Add the lightest coat of water to those greasy city streets and they can be akin to driving on ice.

If the V10's aren't FIA adjusted prior to the event, I expect the Torro Rossa's to turn some fast laps at Monaco. If it rains? I put Toro Rossa in with a shout for the win.

#9 McGuire

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Posted 10 April 2006 - 15:17

Originally posted by J. Edlund
Torque is by itself not interresting


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#10 JwS

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Posted 10 April 2006 - 17:57

Oh when Oh when will people stop having this arguement?
:lol:
Anyhow, if I am recalling correctly, the v10's are both rev limited (to keep down peak HP??) and restricted (to keep down peak torque??).
That said, I could see the arguement that they may be able to make their max (mosley) torque over an extended range of rpm if they were tuned right.
And clearly they are going to be more reliable, if they are still basically the same as last year structurally.
They do seem to have some advantage over the lesser v8s, but they aren't running away.
JwS

#11 Wuzak

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Posted 10 April 2006 - 21:32

I think both measures are to reduce hp.

Interestingly Ferrari's restricted V10 F2004 which they have been used for testing is restricted differently. It's engine management system is programmed to mimic the V8 as close as possible.

As to the RBRs, when I was watching the Saturday practice between turns 5 and 6 at Albert Park it appeared to me that the RBRs were going faster at that point than most, if not all, of the V8s.

I suspect that whilst the RBR is a decent chassis, it is essentially 1 year old and had fallen behind development in 2005. Add to that two inexperienced drivers and I'd suggest that is why they are not beating the world.

#12 Big Block 8

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Posted 12 April 2006 - 07:34

Originally posted by JwS
Oh when Oh when will people stop having this arguement?
:lol:


When all the parties involved finally understand elementary physics. Won't happen too soon, I'm afraid. :)

#13 McGuire

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Posted 14 April 2006 - 18:24

Originally posted by Big Block 8


When all the parties involved finally understand elementary physics. Won't happen too soon, I'm afraid.


Don't be so hard on yourself. You'll get it eventually, I'm sure of it. :D

#14 Stian1979

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Posted 15 April 2006 - 08:24

Originally posted by McGuire


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Annything wroten next to a religious symbol should not be taken to seriously.

Would a diesel with 450Nm winn a race against a 400Nm gasoline engine?

#15 hydra

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Posted 15 April 2006 - 14:05

Sniff Sniff...
I smell trouble brewing :rolleyes:

#16 alexbiker

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Posted 15 April 2006 - 17:41

Area under the torque curve wins races. Not peak torque. Not peak HP. Can we agree on that?

Alex

#17 Kimi on nopein

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Posted 15 April 2006 - 20:20

Originally posted by alexbiker
Area under the torque curve wins races. Not peak torque. Not peak HP. Can we agree on that?

Alex

Umm no. Area under the power curve is what I'd say.

#18 Stian1979

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Posted 16 April 2006 - 01:27

Originally posted by alexbiker
Area under the torque curve wins races. Not peak torque. Not peak HP. Can we agree on that?

Alex


No I can't

Originally posted by Kimi on nopein

Umm no. Area under the power curve is what I'd say.


That I can agree on

#19 hydra

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Posted 16 April 2006 - 05:50

To be more exact, its area under the power curve in the useable rev range, typically the top 30% or so...

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#20 Kimi on nopein

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Posted 16 April 2006 - 07:25

Originally posted by hydra
To be more exact, its area under the power curve in the useable rev range, typically the top 30% or so...

..Provided you can put it to the road... :)
..exept engine output alone doesn't win races..
:lol:

#21 Fat Boy

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Posted 16 April 2006 - 15:16

Well, Mac and I have been around and around on this. I'm fairly convinced that he knows what the correct answer is, but knowing that general purpose answers are often more useful than the 'correct' answer, he repeats 'Torque wins races' like an old 45. He means well, but his mantra is a bit misleading.

In most racing, engine size is limited and RPM in limited. Even if RPM isn't limited, the maximum revs for all the participants is likely to be very close. In this scenario, more torque means that the engine is more efficient. It also lends itself to notion of more HP, if not more peak HP, certainly under the curve. Look at it from Mac's perspective, the most efficient engine, the one with the most torque, will win. His advice is correct, even if the aspect of HP was ignored.

Not too long ago, I was involved in a court case as an expert witness. Without getting too into it, there was a car that was trying to get included into a racing series, and it wasn't being allowed. It's engine was completely different than the established norm. The engine A, the standard, made maybe 150 lbft of torque. Engine B, make around 215 lbft if memory serves. Engine A ran about 25% more revs than engine B. Engine A made 245 HP and Engine B made around 235. Engine B was actually at a disadvantage, but because the defense could grab ahold of the torque difference saying that Engine B was at an unfair advantage. Enter me.

I did simulations to show that the actual acceleration of the car based on these engines was not going to be a based on the engine torque, but engine HP. I also did a graph of HP vs. % of total engine RPM. It showed that through the rev range, Engine A had a consistent, if small, advantage. The defense' arguement fell apart (on many fronts, actually) and they settled out of court.

It's a little tough to find good examples of different engines racing together to show the relative advantages of torque vs. HP. There used to be the Indy car vs. stock block engines at Indy, but that went away. That was a HP thing. Right now you have the Grand Am series where a six cylinder Porsche is whipping up on a bunch of V-8's. I don't think anyone would say the Porsche has a torque advantage. That's all that comes to mind right now. There really aren't a lot of good examples around.

And so the controversy continues and people front all sides still try to pigeon-hole the arguement instead of just running the numbers.

#22 Stian1979

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Posted 16 April 2006 - 16:04

I would say that a engine with a aoutput of 600hp could beat one with 610.
If the engine A has 600hp at 5500RPM and 590hp at 6000RPM and 580hp at 5000RPM if engine B has 610Hp at 6000RPM and 550hp at 6500 and 520hp at 6000RPM.

peak Hp and Nm is not that interesting.
The curve is

#23 BMW4life

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Posted 16 April 2006 - 18:00

Torque=k*hp

hp=k'*torque

Torque and hp are directly proportional to each other, so if one increases, provided k remains constant, then the other increases as well. McGuire's take is very misleading, in all engines, there's a point on the rev range when torque start to drop off, while horsepower continues to increase. So torque is not as important as hp....throughout the entire rev range.

When we hear Renault say that perhaps their engine is not as torquey as another, all they really mean is that at lower revs, they don't make as much hp as the others.

#24 McGuire

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Posted 16 April 2006 - 23:10

Originally posted by Fat Boy
Well, Mac and I have been around and around on this. I'm fairly convinced that he knows what the correct answer is, but knowing that general purpose answers are often more useful than the 'correct' answer, he repeats 'Torque wins races' like an old 45. He means well, but his mantra is a bit misleading.


The statement "horsepower sells cars, torque wins races" is not mine. Everyone from Carroll Shelby to Smokey Yunick to Carroll Smith is known to have said it. The pocket protector crowd often has trouble processing statements like these, which represent not knowledge but wisdom. Watching technogeeks trying to pick it apart is rather like watching a bunch of scientists debating the technical accuracy of the adage "One swallow doesn't make a spring." They are rather missing the point eh. Instead of trying to micro-analyze it for literal meaning, ponder upon what Yunick, Smith, Shelby et al were actually trying to tell you. They won more races than we have seen on television.

#25 McGuire

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Posted 16 April 2006 - 23:16

Originally posted by BMW4life
Torque=k*hp

hp=k'*torque

Torque and hp are directly proportional to each other, so if one increases, provided k remains constant, then the other increases as well. McGuire's take is very misleading, in all engines, there's a point on the rev range when torque start to drop off, while horsepower continues to increase. So torque is not as important as hp....throughout the entire rev range.


What is the proper technical term for the physical property that accelerates the crankshaft?

When we hear Renault say that perhaps their engine is not as torquey as another, all they really mean is that at lower revs, they don't make as much hp as the others.


No, they are saying exactly what they mean, with perfect technical precision. You are merely translating it into your own preferred terms, which requires an additional level of abstraction.

#26 Fat Boy

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Posted 17 April 2006 - 04:05

Originally posted by McGuire


The statement "horsepower sells cars, torque wins races" is not mine. Everyone from Carroll Shelby to Smokey Yunick to Carroll Smith is known to have said it.


You're absolutely right. All of those people did say that. I worked directly with (under) Carroll Smith. He personally hired me on a race team many moons ago. I love it when people invoke his name, because that's one that I can comment on first hand. When I asked him about him writing this particular horsepower/torque comment in a book, he answered essentially how I did in my above statement. We were racing Atlantics at the time. His comments were that most people will get themselves in a lot more success if they had a 'torque' (i.e. broad power band) engine as compared to a more powerful, more peaky engine. Even if it wasn't the theoretically fastest combination, the torquey engine will cover a lot of driving errors.

There's another thing he mentioned. He said that he wrote _Tune to Win_ in the mid-70's. There was no such thing as data acquisition. You set the gears in F-1 and at Lemans the same way you did in Formula Ford on a SCCA weekend, by what the driver told you. They were rarely perfect, and since it was a lot better to guess long than guess short, the engine with the broader powerband was much less sensitive to a slightly screwed up gear stack. Smokey Yunick and Shel were in the same boat. They did most of their racing from the late 40's to the mid-70's. It's no wonder that these guys came to the same conclusions. Even if they knew what gear they needed to put in the car to be 'perfect' there wasn't Fed-Ex or big budgets, so most of the time they had to just 'get it close' anyway.

There are many generalities that are directionally correct, but when actual push comes to shove they aren't correct across the board. A weekend Formula Ford guy that has 8 gearsets for an entire season of racing is going to have a different engine requirement than a well-funded professional race team. It's just part of life.

Carroll Smith came to Long Beach a couple years ago and looked many of his old Atlantic people up. I talked with him for about fifteen minutes and then had to run (I think my car was on the pad or something). Later in the day I looked him up and probably talked for a good hour on what was going on. It was the first time I'd seen him in years, and he was playing with an historic F-1 car and really looking pretty good. Less than two months later I was at his funeral. I only hope I can have that many people send me off when the time comes.

#27 Ross Stonefeld

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Posted 17 April 2006 - 07:39

Originally posted by Fat Boy


You're absolutely right. All of those people did say that. I worked directly with (under) Carroll Smith. He personally hired me on a race team many moons ago.



With the next bulletin board update we need a bow-down smiley. :up:

#28 McGuire

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Posted 17 April 2006 - 09:48

Originally posted by Fat Boy


You're absolutely right. All of those people did say that. I worked directly with (under) Carroll Smith. He personally hired me on a race team many moons ago. I love it when people invoke his name, because that's one that I can comment on first hand. When I asked him about him writing this particular horsepower/torque comment in a book, he answered essentially how I did in my above statement. We were racing Atlantics at the time. His comments were that most people will get themselves in a lot more success if they had a 'torque' (i.e. broad power band) engine as compared to a more powerful, more peaky engine. Even if it wasn't the theoretically fastest combination, the torquey engine will cover a lot of driving errors.


I knew Smith as well. Also Shelby, and I worked with Yunick for some time. You can't claim any special knowledge there, though you would obviously like to. This is as true today as it ever was, in Formula Ford or Formula 1: a wide torque band beats max hp. You can call it a "wide power band" if you want, but you are really talking about torque. No torque = no hp, no getting around it. Power is simply the rate at which work is performed.

The current deal in F1 is one more example. Compared to last year's V10, the current V8 is running at 100% power around a greater percentage of the track. That may suggest that more than ever, max hp is "more important" than torque... except for this: what accelerates the crankshaft UP TO max hp rpm?

#29 McGuire

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Posted 17 April 2006 - 09:56

Originally posted by Fat Boy



There's another thing he mentioned. He said that he wrote _Tune to Win_ in the mid-70's. There was no such thing as data acquisition. You set the gears in F-1 and at Lemans the same way you did in Formula Ford on a SCCA weekend, by what the driver told you. They were rarely perfect, and since it was a lot better to guess long than guess short, the engine with the broader powerband was much less sensitive to a slightly screwed up gear stack. Smokey Yunick and Shel were in the same boat. They did most of their racing from the late 40's to the mid-70's. It's no wonder that these guys came to the same conclusions. Even if they knew what gear they needed to put in the car to be 'perfect' there wasn't Fed-Ex or big budgets, so most of the time they had to just 'get it close' anyway.



It's still better to be geared too long than too short, same as it ever was. We now enjoy a smaller margin of error, that's all. It's not just the availability of gearsets that has changed. Engines are now a whole lot better than they used to be. Electronic engine controls, more dynos than ever, flow technology, cam science. Where has all this development focused?

#30 Fat Boy

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Posted 17 April 2006 - 15:21

Originally posted by McGuire


I knew Smith as well. Also Shelby, and I worked with Yunick for some time. You can't claim any special knowledge there, though you would obviously like to.


Mac, I'm keeping this civil and I would ask that you do the same. People tend to invoke the name of "X" in their arguements. You pulled Smith, Shelby, and Yunick. I knew one of them, and have actually talked about this subject to him. (I've said "Hello" to Shelby and Yunick, but that just doesn't count for much in this discussion, huh?) I think at this point, it's fair game to bring that up. I've been on this board for a long time without claiming anything special, and I'm not trying to start now. You brought him up, though, so it's gotta be fair game. I have to say, in many circumstances I'll use in an arguement "Because Newton said so" or "Because Bernoulli said so"....I pull the same crap.

I'm not going to go through the math on this. We've been down this road. We get to the same point. You feel that my approach ignores certain aspects of the problem, and I feel you go around the barn to get to the front door. We aren't going to change that, and I'm not going to try.

As far as what development has been geared toward over the last several years, I would argue that whether you are running Cup or Formula 1, the most impressive gains over the last 10 years have been in RPM without hurting reliability. I doubt if overall engine efficiency has improved more than a percent or 2. The gains in RPM have been on the order of 25%, though. Now, tell me, if torque is the controlling factor on all this, why the constant push towards more RPM? If the whole game is torque, wouldn't you want to keep RPM low in order to reduce the friction that will reduce the torque output?

Maybe I'm just being the devil's advocate here, but regardless, these are questions that should be answered.

Gears and engine powerband (torqueband if you want) selection are not a simple task. In most situations, certain corners around a track will play a big part in what gears you choose as opposed to what would be theoretically perfect for acceleration. I agree with Mac that it's better to be geared long that short. It's best to be geared perfectly, though. When we have discussions on theoretical aspects like we're doing now, we should start at the 'ideal' scenario and work towards reality. I still feel that's what Mac is doing, maybe more on instinct that actual planning. He's got enough first hand experience to know that reality means imperfect gears, corner speed determining gears, going off line to pass, etc. Because of that, he likes a 'torquey' engine to race with. I don't find a lot of fault with that except to say that it is not always the best.

Just like their are no magic spring rates or magic shocks, there is also no magic in the engine. It's all a series of compromises. Sometimes I've had the engine and gearing in more of a 'peaky' arrangement to qualify and a 'torquey' arrangement to race. The 'peaky' arrangement at some tracks is better for putting in a single fast lap, but the 'torquey' arrangement is better for running the race and dealing with all you have to deal with in a race. It's not that I was wrong for qualifying and right for the race or the other way around. It just means that I made different compromises based on what I was trying to acheive.

#31 NTSOS

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Posted 17 April 2006 - 20:05

Now, tell me, if torque is the controlling factor on all this, why the constant push towards more RPM? If the whole game is torque, wouldn't you want to keep RPM low in order to reduce the friction that will reduce the torque output?



But it is the controlling factor...what would be the point of increasing RPM's and not try to increase or maintain torque as the RPM's increase.....which would in turn increase the HP dramatically!

As we all know...... :|

The higher the HP at a *specific* RPM, the higher the torque will be.

The higher the HP at a *specific* RPM, the higher the torque will be.

or

The higher the torque at a *specific* RPM, the higher the HP will be.

The higher the torque at a *specific* RPM, the higher the HP will be.

What is it about this simple concept that makes people crazy? :cry:

Most = most.....at a specific RPM.

A motor tweak at a static RPM!

800 hp @ 17,000 - 247 lb/ft

805 hp @ 17,000 - 249 lb/ft

810 hp @ 17,000 - 250 lb/ft

815 hp @ 17,000 - 252 lb/ft
__________________________

Now....what would be the point of this as compared to the above?

800 hp @ 18,000 - 233 lb/ft

805 hp @ 18,000 - 235 lb/ft

810 hp @ 18,000 - 236 lb/ft

815 hp @ 18,000 - 238 lb/ft
__________________________

...or this dynamically!

800 hp @ 17,000 - 247 lb/ft

805 hp @ 18,000 - 235 lb/ft

810 hp @ 19,000 - 224 lb/ft

815 hp @ 20,000 - 211 lb/ft
__________________________

....or does this make more sense?

800 hp @ 17,000 - 247 lb/ft

850 hp @ 18,000 - 248 lb/ft

900 hp @ 19,000 - 249 lb/ft

950 hp @ 20,000 - 250 lb/ft
__________________________

...or to maintain a torque curve!

800 hp @ 17,000 - 247 lb/ft

847 hp @ 18,000 - 247 lb/ft

893 hp @ 19,000 - 247 lb/ft

940 hp @ 20,000 - 247 lb/ft
__________________________

....how about maintaining a HP curve? :rotfl:

800 hp @ 17,000 - 247 lb/ft

800 hp @ 18,000 - 233 lb/ft

800 hp @ 19,000 - 221 lb/ft

800 hp @ 20,000 - 210 lb/ft

John

#32 toe-out

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Posted 18 April 2006 - 02:53

The simple way of looking at this debate is gearing. If you have 1 speed, torque is king. If you have CVT, horsepower is king. With the usage of 7th gear, torque advantage of the bigger V10 is diminished a bit.

If the both engines have the same hp, the bigger engine would be better between shifts. Every time there is a shift, the bigger engine would put out more power at reduced rpm. The only thing that's not clear is how the FIA limit the V10.

#33 Fat Boy

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Posted 18 April 2006 - 04:20

Originally posted by NTSOS


But it is the controlling factor...what would be the point of increasing RPM's and not try to increase or maintain torque as the RPM's increase.....which would in turn increase the HP dramatically!
------------------------------------------------SNIP---------------------------------------

...or to maintain a torque curve!

800 hp @ 17,000 - 247 lb/ft

847 hp @ 18,000 - 247 lb/ft

893 hp @ 19,000 - 247 lb/ft

940 hp @ 20,000 - 247 lb/ft
__________________________

....how about maintaining a HP curve? :rotfl:

800 hp @ 17,000 - 247 lb/ft

800 hp @ 18,000 - 233 lb/ft

800 hp @ 19,000 - 221 lb/ft

800 hp @ 20,000 - 210 lb/ft

John


OK, let's look at what we have here. Torque is a measure of the total efficiency of an engine. There will be flow, combustion, heat transfer, friction and other components. They all add up and produce an overall efficiency. Torque is essentially a measure of that efficiency and the displacement of the engine.

We get heat by burning fuel. We turn a portion of that heat into kinetic energy. With a standard internal combustion piston engine, we can figure that 1/3 of the stored energy is cast off as waste heat, 1/3 is heat expelled out the tailpipe, and 1/3 is turned into kinetic energy off the crank. This is pretty much a best case scenario. As the total efficiency drops, less and less of the energy of the fuel is used to turn the crank.

Let's say a certain engine is burning a fuel with an energy density=E at N rpm. The torque coming off the crankshaft will be a product of 1/3*E. The power off the crankshaft can be represented by 1/3*E*N. Let's say we double the RPM of this engine. When we do, we lose frictional, combustion, and flow efficiency and so our total torque is now represented by the product 1/4*E. The motor is clearly less efficient. However, the RPM has doubled, so even though the engine is not as efficient, it's processing a lot more fuel. The power term is now represented by 1/4*E*2*N or 1/2*E*N. The motor might not be as efficient, but even so, it's burning more fuel and because of that there is more kinetic energy being released from the end of the crank. If we are accelerating from a given speed with both scenarios (gearing being the variable), then the example with more power (energy per unit time) will accelerate faster even though the torque off the crankshaft will be lower.

What engine builders have found is that there are only certain amounts of gains to be had in the total efficiency department. You can narrow bearings to reduce friction, but some will still be there. You can help the airflow. You can make better combustion. At the end of the day, though, there's only small gains to be had in the efficiency of an engine. They're all very important, but very small. The easier gain at this point is to increase engine speed and simply burn more fuel. It hurts fuel efficiency, but it's the best way to get the car down the track.

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In the first example I've copied from NTSOS, we get what engine builders shoot for. A broad, steady torque curve. This means that they have a very consistent total engine efficiency (hopefully, it's consistently high). In reality, at these types of RPM, friction is a huge deal. You just can't maintain a consistent torque. We can try, though. What you end up shooting for is efficiency dropping at a slower pace than RPM is increasing. As long as the % drop in efficiency (torque) is less than the % increase in RPM, you're going to make more power.

The second example from NTSOS seems unrealistic, but it's actually quite close to what you get when running an air restricted engine such as the Toro Rosso car or a Lemans sportscar. The point that the restrictor comes in is pretty abrupt, and after that point, torque falls fairly rapidly. At some point in the rev range, the HP just goes flat for a while. The efficiency and RPM plusses and minusses equal out for a portion of the rev band (say 500 RPM). After that, both fall off pretty rapidly. It makes it easier to set gearing, that's for sure. You don't have to worry about being right on the money. You just have to worry about getting it close. If it over-revs a little, no biggie. If it underrevs a little, well, you're probably still running in the neighborhood of maximum average Hp, because +/- 100 RPM just isn't an issue. In that respect, it's a nice way to control engine power as a racing series.

So I've probably just opened another can of worms. I just wanted to try and convey in reasonable, yet unspecific, terms of what is going on. I hope I helped.

#34 Stian1979

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Posted 18 April 2006 - 05:59

Annyone here got a weekend racer?
If you have a grapical torque and power curve you can try to sett a fastest lap around a circut and look at what RPM you change gears and then look at where on the torque curve and where on the power curve you have ben at that lap.

I'm quite shure the torque curve is far from the peak moust of the time maybe only on the aceleration from the start will you pass it on the RPM scale, but you are over and under the peak power a dusin times.

...or this dynamically!

800 hp @ 17,000 - 247 lb/ft

805 hp @ 18,000 - 235 lb/ft

810 hp @ 19,000 - 224 lb/ft

815 hp @ 20,000 - 211 lb/ft

Good exsample

#35 Lukin

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Posted 18 April 2006 - 11:55

Originally posted by Fat Boy
I only hope I can have that many people send me off when the time comes.


If there will be a good looking widow left behind I will definately pay my respects ;)

#36 Fat Boy

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Posted 18 April 2006 - 11:59

Originally posted by Lukin


If there will be a good looking widow left behind I will definately pay my respects ;)


It's always the high road for you, isn't it? Hey, if she's game what will I care?

#37 Stian1979

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Posted 18 April 2006 - 12:06

Originally posted by Lukin


If there will be a good looking widow left behind I will definately pay my respects ;)


I have ben working in Australia and New Zealand and I shure miss there personalety and humor.

#38 Big Block 8

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Posted 18 April 2006 - 12:26

Originally posted by McGuire

Don't be so hard on yourself. You'll get it eventually, I'm sure of it. :D


As I haven't been the one who tries to seriously tell folks that force and lever arm are NOT interchangeable, when torque is concerned, I'm not the one in the most desperate need of an elementary physics course. :D

#39 CIN

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Posted 18 April 2006 - 13:40

As everyone here knows. Peaky engines are harder to drive fast then engines that have a broad power curve. You just need to drive a 9000rpm street n/a engine and a 7000rpm turbo charged engine(or a big capacity low rev engine) to appreciate the huge difference in engine behaviour.

How fast the engine is actually around a track in reality will depend on the gearing and the actual track provided that the driver can drive both engines equally as good.

If I had to choose an engine with more hp high up(more torque higher) and one with less hp but more hp down low it would depend on where the car is run, tyre choice, gearing and a lot of other things. A car with a lot of torque could eat tyres much faster if the driver can't manage well. Take traction control off the current F1 cars and the situation would become even more complicated.


BTW. Greetings to you all! This is my first post! :)

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#40 McGuire

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Posted 18 April 2006 - 15:21

Originally posted by Fat Boy


Mac, I'm keeping this civil and I would ask that you do the same.


Really?

"Well, Mac and I have been around and around on this. I'm fairly convinced that he knows what the correct answer is, but knowing that general purpose answers are often more useful than the 'correct' answer, he repeats 'Torque wins races' like an old 45. He means well, but his mantra is a bit misleading." -FB

Sounds to me like your perspective is important and others are not. This whole deal is mainly a matter of perspective. If an engine is something that comes in a black plastic crate, torque may not matter to you. However, if you are building and developing engines, torque is the game.

#41 NTSOS

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Posted 18 April 2006 - 15:45

You just can't maintain a consistent torque. We can try, though. What you end up shooting for is efficiency dropping at a slower pace than RPM is increasing. As long as the % drop in efficiency (torque) is less than the % increase in RPM, you're going to make more power.


Posted Image Nice piece!

I have taken the hits before, but I find it easier for me at least, to just concentrate on the torque curve and try to keep the values up as much as possible across a particular operating range and the HP will follow merrily and willingly along.

And for your intertainment value.....kind of an interesting street motor.....the 2nd half of this Katech dyno pull zooms in on the data.

Enhanced LS7

John

#42 McGuire

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Posted 18 April 2006 - 15:50

Originally posted by Big Block 8


As I haven't been the one who tries to seriously tell folks that force and lever arm are NOT interchangeable, when torque is concerned, I'm not the one in the most desperate need of an elementary physics course. :D


Force and lever arm are NOT interchangeable. When doing the arithmetic the terms are commutable on either side of the multiplication sign, but that is as far as it goes. Work has three components: force, cause and displacement. In all cases a force causes a displacement. We do not hold that displacement causes the force. If that were true, absurdities such as perpetual motion and free energy machines would be possible.

#43 shanba

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Posted 18 April 2006 - 16:44

The push for increasing RPM allows for lower inertia drivelines (due to lower torque being transmitted) and thus less energy wasted accelerating that inertia and more energy accelerating the car.

#44 McGuire

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Posted 18 April 2006 - 17:11

Originally posted by NTSOS


I have taken the hits before, but I find it easier for me at least, to just concentrate on the torque curve and try to keep the values up as much as possible across a particular operating range and the HP will follow merrily and willingly along.


Yep, there is another old saying, this one from the dyno room... "take care of the torque curve and the hp curve will take care of itself."

It is a simple matter to squeeze another 500 rpm out of any engine. The trick is in sustaining the torque curve enough to produce an actual power gain.

#45 NTSOS

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Posted 18 April 2006 - 17:52

It is a simple matter to squeeze another 500 rpm out of any engine. The trick is in sustaining the torque curve enough to produce an actual power gain.



Posted Image Posted Image Posted Image

John

#46 Big Block 8

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Posted 18 April 2006 - 17:54

Originally posted by McGuire

Force and lever arm are NOT interchangeable. When doing the arithmetic the terms are commutable on either side of the multiplication sign, but that is as far as it goes. Work has three components: force, cause and displacement. In all cases a force causes a displacement. We do not hold that displacement causes the force. If that were true, absurdities such as perpetual motion and free energy machines would be possible.


Just curious, do you also sell people little bottles of Godly Goo, that cures everything?

#47 alexbiker

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Posted 19 April 2006 - 22:13

Originally posted by Kimi on nopein

Umm no. Area under the power curve is what I'd say.


I've been away for a few days, so I didn't see this until now.

I'll be away for another few days thumping my head against a desk in frustration at this post.

Bye.

Alex

#48 Stian1979

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Posted 20 April 2006 - 15:04

Can annyoe tell me why anybody actualy care about torque?
In the design off tug boats you would think torque is important from the statements done on this forum, but it's not. When we pick a engine we pick it from the powercurve, as a mather of facts moust marine diesel supliers don't have anny torque data. You get a diagram x and y aksis where you have load and rpm and a hp curve shoving the power at certain load conditions and rpm.
Several curves are ploted in like turbopreshure, exhaust temperature, g/kw and so on, but torque is of no interest even for pulling huge oil tankers

#49 alexbiker

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Posted 20 April 2006 - 17:03

Thanks for that.

What has it got to do with cars in any way? I would suggest; nothing.

The statement that in cars, torque curves are irrelevant compared to the power curve:

Originally posted by Kimi on nopein

Umm no. Area under the power curve is what I'd say.



is so breathtakingly ignorant of the relationship between the two, and that the power curve is just torque related to engine speed that it blows my mind someone would say it. To suggest this is to suggest that HP is a real physical value and that torque is not, and that power is somehow not just work done per unit time.

Mindmelting.

Alex

#50 Stefan_VTi

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Posted 20 April 2006 - 17:37

alex: better take your personal feelings elsewhere

An engine is an engine, it doesn't matter a thing if propels a car, bike or boat. Same physics apply.

Kimi was spot on with his remark.
Both Torque and HP are valid physical phenomenons. Torque (as said before) is a dimension without a time component and serves great purpose for an engine builder (in that he can see how efficient the strokes of an engine are at a certain parameter set, eg. 5000rpm & 100% throttle).

What the chassis folks want is to know how often the engine can exert this force to the gearbox per given unit (say seconds). Now let HP show just this! That is why for vehicle performance HP is what matters. Torque delivered over time.