enzom

Skratch - It wasn't a question of catching up and reeling in, it was a question of maintaining the gap. The Gallardo kept driving away. By the way, how the heck can you read that tac in the video. I can barely make out the cars, and my vision is pretty good.

Look, that the M5 could stay close is a tribute to what a great highway car it is. Nobody is trying to say that the car isn't fast. And I for one do not dispute that the M5 would have done better at the start if it were revving at 6,000 rpm than 5,000 rpm (assuming it was at 5,000 rpm). But once it was in its powerband and approaching 120 mph, it was still losing ground. It lost. It would have lost if it started at 6,000 rpm. You win some; you lost some.

Improviz

You implied it, when you claimed, wrongly, that its acceleration would be bad at its torque peak because it was "100 horsepower down" or some such ignorant nonsense, which implies would be better at its horsepower peak.

So let me get this straight: rather than simply admitting you were wrong, you are instead attempting to redefine the Industry Standard definition of power band to mean torque peak??

Get real. You cannot arbitrarily redefine the meaning of words simply because you don't have any knowledge as to their meaning. And the term "power band" is widely used, and is defined as:

http://autorepair.about.com/library/.../bldef-274.htm
POWER BAND

Definition: The subjectively defined rpm range over which an engine delivers a substantial fraction of its peak power. The power band usually extends from slightly below the engine's torque peak to slightly above its power peak.

Simple as that.

And all you've been doing is whine from the beginning of this thread about how "Oh, gee, if we only would have stacked the odds in the M5's favor, it coulda, shoulda, won, guys...golly! Gee! The M5 is, like, totally my dream car, and I like totally like to annoy you guys with, like, silly ignorant posts! Gee! Golly!! Wiz bang!! OK, I gotta go now; Mom's calling me for supper!!!"

I mean, what use is a performance car if as you wrongly claim it only makes decent power over a 2,000 rpm range?? Do you realize how dumb this sounds? Your understanding of this term is as off the mark as is your understanding of Physics.

There is only one person here who has been proven wrong, and it is you. You falsely claimed that there is a dip in the motor's torque at 5,000 rpm, declining downwards from there, but the BMW factory engine graph shows that you were absolutely, totally wrong.

Then you claimed that the M5 wasn't in its power band. Again, by any definition of power band, you're shown to be wrong. The power band is a RANGE of RPM, not a SINGLE rpm. And now you are wrong, yet again, about the Lambo as well:

Why don't I go ahead and explain that the Earth is not flat while I'm at it? You are arguing that a car which weighs 400 pounds (actually, it is closer to 500 pounds) less, which has the same rated horsepower, should be slower??

Car & Driver's data on the Gallardo:

As to its torque peak coming in lower: again you show a total lack of understanding of the principles of acceleration. The Lambo's lower torque peak might hurt if if its engine did not produce good torque near redline, but a simple Algebra 1 calculation shows that it's just fine up there, think you very much:

Horsepower is defined as torque*rpm/5252, so torque = horsepower*5252/rpm. The M5 has its torque peak of 383 lb-ft about at 6.100 rpm and its horsepower peak of 507 horsepower at 7,750 rpm (going by the chart above); the Lambo has its torque peak of 376 lb-ft at 4,500 rpm, and its horsepower peak of 493 at 7,800 rpm.

At 7,750 rpm the M5 is making 507*5252/7750 = 343 lb-ft.

At 7,800 rpm the Lambo is making 493*5252/7800 = 331 lb-ft.

What about the M at the Lambo's peak of 4,500? From the graph above, it is making about 460 Nm at 4,500 rpm, which works out to 339 lb-ft.

So at 4,500 rpm, the Lambo is making its max torque, while the M5 is 12% down from its peak. At both engines' torque peak, 50 rpm apart, the Gallardo is still making 97% of the M5's motor, roughly the same percentage of the M5's peak torque that its peak torque is (376/383 = 98%)

In other words, the Lambo's motor has a *much* wider power band than the M5, with a torque peak coming in 1,600 rpm lower than the M's 6,100 rpm peak, yet still making the same proportion of its max torque near redline as the M. Meaning that it is a better motor. Which one would expect in a car costing that much more than the M.

Which goes to show, once again, that you really don't know what you're talking about here.

Finally, there is the EVO test I mentioned earlier, where the kind authors actually performed a head-to-head of these two automobiles. Here is what they had to say about running the two head to head in rolling start races. If you read it carefully, you will see that they kinda, sorta mention that the Lambo's wider torque (power) band gives it better on-the-fly acceleration:

Attacking the same stretch of road, Lamborghini leading, Green now following in the M5, it's easy to see how the Gallardo can toy with the BMW. Its engine, so vocal and energetic, summons greater low-rev and mid-range torque, something that feels all the more impressive in a car that weighs a third of a ton less than the M5. Consequently, when you plant your right foot to the floor the Lamborghini genuinely leaps forward, while the M5's more highly-strung torque delivery and extra bulk mean it takes an extra few crucial moments to hit its stride.

And this shows up in the as-tested acceleration numbers as well. The M5 was slower from a dead stop to every 10 mph increment tested, which fyi is from 30 to 160 mph. The M5 did not come out ahead in one. Not a single one.

Highlights: M5 Gallardo
0-60: 5.0 4.7
0-80: 7.4 7.0
0-100: 10.4 10.0
0-130: 16.7 16.2
0-160: 27.6 26.7

The in-gear times give an even better illustration of how the Gallardo's wider,
fatter torque band give it a huge advantage over the M5:

Third gear: M5 Gallardo
40-60: 2.7 1.9
50-70: 2.7 2.0
60-80: 2.5 2.2

Fourth gear: M5 Gallardo
30-50: 4.0 3.1
40-60: 3.7 2.7
50-70: 3.5 2.5
60-80: 3.5 2.5
70-90: 3.5 2.8
80-100: 3.4 2.9
90-110: 3.4 2.9

Fifth gear: M5 Gallardo
30-50: 5.0 4.7
50-70: 4.6 3.5

Sixth gear: M5 Gallardo
50-70: 5.8 5.1
70-90: 5.2 4.3

Why don't you stop whining and admit that in this, the first video we have of two non-press cars going at it, the M went down, and all the excuses in the world won't change that? "He coulda been a contender" just doesn't wash.

Improviz

Yes, but this still boils down to the equation I provided earlier. The force at the wheels is primarily the product of the torque at the crank multiplied by the gearing, less parasitics, etc.

So if in your example the car makes less torque at 4,000 rpm but it is in a lower gear which provides higher torque multiplication, then yes, assuming the ratio is not close in the next gear, it will accelerate faster. But this is due to the dramatic dropoff between gears in the multiplication of gearing, and does not change the basic equation, which is, at all rpms, the product of torque times driveline multiplication.

Numerically, suppose Car A has a perfect, lossless driveline, wheels with a radius of 0.5m, makes 650 Nm of torque at 3,000 rpm, 400 hp at 5,500 rpm, and redlines at 6.000 rpm. Its third gear final drive ratio (by which I mean product of gear w/rear axle ratio) is 3:1. Its fourth is 1.75:1

I'll look at three cases:

First is at its max torque peak in third. Wheel force would be 650*3/0.5 = 3900 N.

Second is at its power peak in third. Torque-wise, it produces 400*5252/5500 = 382 lb-ft = 517 Nm. So in third gear at its horsepower peak, force at the wheels would be 517*3/0.5 = 3102 N. Note, skratch, that this is less than the value at its torque peak.

Third case is in In fourth. Max force possible would be at the torque peak, equal to 650*1.75/0.5 = 2275 N. At its horsepower peak, this drops off to 517*1.75/0.5 = 1810 N.

So you can see that max wheel force in third and fourth occur, as they should, at the engine's torque peak. But it would still be better to be in third gear close to horsepower peak, because gear multiplication in third overcomes torque gain at lower rpm in fourth.

And the equations show why: the gearing ratio, and hence the multiplication, in the second case has dropped.from 3 to 1.75, a 42% decrease. But the torque only went up from 517 to 650--an increase of 26%, not nearly enough to compensate for the dropoff in gearing.

It always boils down to force, in the form of torque. What maximizes acceleration is a wide, flat torque band with gear ratios matched to keep the engine in the heart of this torque band in each succsssive gear for the maximum time.

Mardeth

You seem to know alot about the physics behind the performance so maybe you could maybe explain something to me. Let me make an example to clear up what Im asking.

Lets look at running. As far as I understand torque in running would determine the lenght of your stride and rpm how many strides you take. So if one guy takes leaps of 4m at 1 stride a sec and another 2m at 2 strides a sec. So their moving at the same speed.

It probably doesnt in such a linear fashion in cars but isnt it same principle? All other things aside, if one car is making 200Nm 1900-2100rpm and another 100Nm between 3900-4100rpm. Isnt the acceleration around the same in these two? Or am I totally off base?

reggid

From my perspective i am talking generally performance and yes predicting performance with good accuracy is best left for someone with more time on their hands. IMO the main reasons between the discreptancies between paper and the real world are the human factors and the data provided my manufacturers.

Improviz

Hoo, man, you opened up a can of worms there. I'm going to stick to cars, though....and try to do it without using any Calculus, although I'll have to kind of hit a bit of it...

As I said earlier, the instantaneus acceleration of any object with an applied force is acceleration = force divided by mass. But the key word here is "instantaneous", because it truly is a snapshot in time.

And time is the key here: suppose, hypothetically, that you had a car which produced, say, 100 ft-lb of torque from idle to 3000 rpm, 500 from 3001 rpm to 4999 rpm, and back to 100 from 5000 rpm to redline.

So, if you look at its acceleration as a function of time, as it cycles through the rev ranges, the thing would be a slug, then really fast, and then a slug again.

Contrast this with another hypothetical engine which made 500 lb-ft from 0-redline. That thing would go like stink anywhere in the rev range.

Now if you compare this one to the previous one, and make gearing, weight, all other factors equal on both cars, you'd see that even though at certain points of time both would be accelerating at the same rate, overall the second car would stomp the crap out of the first car, since it would be producing this force *all through* the gear range, while the second car would be only producing it part of the time.

This is where the calculus comes in: the concept is known as an Integral. What determines the total 0-xxx time is the amount of energy expended to accelerate the vehicle for the total amount of time expended. Sort of like the difference between the speed you're going in a car at any given moment and the total number of miles you've traveled at the end of an hour. What determines the latter is the integral of your speed function over the hour...same thing with acceleration: what determines the speed you'll hit is the level of force applied, *and* for how long.

Meaning that the rate at which you accelerate at any given *instant* in some time period is a function of the torque times the gear ratio at that instant, but how fast you'll be going at the *end* of that time period depends upon the total amount of energy applied over the entire period.

So the perfect car would have a flat torque curve from 0-redline. Can't do it. But you can try to kind of trick the car into having it via gearing, which is the one concept that skratchy actually seems to have an inkling of; if you set up your gears such that after each shift you're in the power band until you get to the next gear, then do it again, and again, etc., then you can basically use gearing to give you a nice, smooth acceleration curve...

But you always lose power with the drop off in gears; as I showed in my example to reggid, if your gear ratio drops, which it does as you upshift, then even if you keep it in the meat of the power band on each upshift, you still lose lots of power (I'm using power here in place of force, but force is what I'm talking about; I'm just trying not to sound like Mr. Spock too much)...so ideally, you would have good gearing *and* a wide torque band so that when you're *in* a certain gear in the power band, you can *stay* there for a while and keep that power coming for the maximum time. It's the second part that skratchy failed to grasp.

This is why that Lambo motor is such a killer piece of work: it makes very high torque for damn near 4,000 rpm, from about 4,500 rpm up to 8,100. The M's motor, as good as it is, has a much shorter RPM range from its torque peak to its redline and is thus much more peaky.

But both have one thing in common, as do most well-designed motors: since the speed in gears that you can go is also a function of engine speed, you ensure that you can stay in the gears longer by making the engine produce its horsepower peak close to its redline. So in your two examples, while it is true that both would have the same peak acceleration, the car with the higher rev band would allow you to set up the gearing to maximize its acceleration while holding the gears to higher speeds.

Hope this sheds some light...kind of typed it out in a hurry!!

The following writeup is a really good one, btw:
http://vettenet.org/torquehp.html

reggid

the race started from a particular speed in 2nd gear if they changed to first it would be 7.5k.

Why shoukd the m5 start at its optimum and the other car not?

reggid

if you take two identical cars and line them up one takes off 0.1 sec before the other the gap (in terms of distance) will always increase but the gap (in terms of time) will be the same! I think i've got that correct.

reggid

Its easiest to look at the power the motor produces to see whether the change in gearing is enough to offset the reduced torque. Compare the power at the torque peak to power at any other point above the rpm of peak torque to show which gear is the best.

reggid

the ideal engine a gear box engine is an engine with alot of peak power with CVT. Peak torque would be irrelevant in terms of pure performance. That way you can run an engine at max power and vary the CVT to vary speed.

Force = power/velocity

Improviz

I did watch it, again, closely, and you're full of ****. The tach is on the right, and as can be clearly seen from the attached screen capture at the beginning of the video, the tach is at 3:00, which does NOT translate to 5,000 rpm.

Here is the link to the video. You don't even need to pause it...it's the first frame. Load it up and stop it, any fool can see this.

I've attached both the instrument panel from a new M5 and the tach shot from the beginning, i.e. the first frame, of the video below it.

You really are an idiot.

cte430

God, that interior is ugly. Every time I see it, I'm amazed ths is what they came up with.

skratch77

are you blind.he clearly states hes in second gear and he is at 5k (5.21 if you wana be so **** about it) before the first beeps and keeps it there till the go.

zumbalak

I think the capture from the vid shows the rpm to be a bit higher than 5500.

Improviz

You are like the Energizer Bunny of stupidity....no matter how many times you're proven to be wrong, you keep going and going and going and...I mean, the M5 instrument panel I provided plainly shows the numbers, and the image I scanned, from the first video, frame 1, plainly shows that the RPMS were closer to 7,000 RPM, NOT 5,000.

And, as with pretty much other claim you've made in this thread, your RPM claim too is bull****; he made no mention of the rpms at which he started the race; he only stated that he started at 60 km/h, in two, not one, posts:

First post, the one in which he posted the bloody videos:
Second post:
Really careful reading there, genius... 60 km/h in an M5 in first gear does not work out to 5,000 rpm, end of story. And that tach shot is from the very first frame of the video. The M5's tach goes to 9,000 rpm. 3/4 of 9,000 is not 5,000, moron.

The M5 does 5.5 mph/1000 rpm, or 8.8 km/1000 rpm. So do the math, or better still, I'll do it for you since you're both mathematically and English-challenged: 60 km/h /(8.8 km/h/1000 rpm) = 6.8*1000 rpm, meaning the car started the run at 6,800 rpm. Which gels *exactly* with the position on the dial of the tach in my scanned image.

So, not only can you not even understand plain English, even a pretty picture doesn't help you. Which begs a question: at what age were you lobotomized???

Btw, given your lack of reading skills, I'm certain that you're unaware that there were two, not one, videos of these cars running: here is the second:
http://media.putfile.com/G-vs-M5 .

In it, you can clearly see that even when the M jumped out in front at the begining, the Gallardo reeled it in and blew by it. Again: at what age were you lobotomized???

enzom

Impro, settle down, man. You are going to give yourself a heart attack. Yes, you are correct. The M5 started at closer to 7,000 rpm. But the name calling is not really necessary. Down, boy.

Improviz

Just getting sick of this punk kid acting like the M5 is the greatest car ever known to man, and unbeatable. That's all he ever does here, and it's annoying. If he wants to constantly talk about how wonderful BMWs are and how many callouses he's gotten on his hands from whacking off to M5 articles, great: he can do it at Gustav's forum. But it's insulting to constantly have a know-nothing idiot trying to lie and obfuscate in constant defiance of clear facts.

Lying is a violation of the terms of use, and that's all this punk does: lie and make excuses.

enzom

I find stuff like that annoying, too. Well, the ball is in his court now. He either needs to show us that the M5 was at 5,000 rpm (a link to another site where the driver says that he was at 5,000 rpm; a calculation that shows how, based on speed, the car had to be at 5,000 rpm) or admit to being wrong.

skratch77

just to clarify im talking about the viper video.Pause the video at 4 seconds and look at the tach its right at the first beep and its under 5.3k

they said they were doing 60.that sounds right with its gearing there in second gear in that race and you can hear the guy say he is.

second gear goes to 80mph in that car fyi

why dont we ask some one who has the car where second gear at 60 sits on the rpm tach and we can end this

Improviz

Here is what he said:
He was doing 80, in second....80 km/h is 50 mph. Given that the car redlines in first at 45 mph, it would be a bit difficult to run it in first gear from that speed.

And per fastsaloons.com, second gear revs are 8.3 mph/1000 rpm. So 50 mph in second works out to (drumroll, please):


Which, I believe, ah, yes, it is exactly 100 rpm away from the car's torque peak at 6,100 rpm.

I suppose this isn't in the car's power band either...

They started at 60 km/h versus the Gallardo; versus the Viper they said 80 km/h, in second gear, as quoted above.

Again, you're confusing the two races. Read his post again if you don't believe what I quoted above to be accurate, which it is.

Nope. 68 mph, per fastsaloons.com.

Fastsaloons.com has the speed in gear numbers, so it is easy to obtain the mph/1000 rpm numbers from them. Look for yourself....for a change.

jordan

Guys, I don't know why Scratch and others are so upset or questioning the gearing? If the M5 is doing 30 mph, he is prob in 1st gear at 5,500 RPM. That is factual and can not be argued. Tell me if I am wrong and if so I "can show proof".

He was in first gear, that makes Scratch wrong. He was doing 5,500 RPS and that makes others wrong because 1st gear at 30 is 5500 rpm, if it was at 6,500 rpm he would have to be in a lower gear than 1st. AND THAT is not possible. And, I so happen to love the M5 as I do all Fast cars, but, I would have to say that the Gallardo is a tiny bit faster till 120 mph as it is lighter and is expected to be.

The video show the G pulling a bit and staying ahead, yea sure the M would have caught it after 120 plus, but they didn't wind them out because of room. Put them on the highway from a dead stop and let them run 1 mile, my money is on the M5, 1/2 mile money is on the G. And yep, I am new to the board, hello

Jordan

enzom

Welcome to the board. Actually, the video shows the G continuing to draw away until he lifted for traffic at 220 kph plus (according to the driver's post). 220 kph is more than 120 mph. The M never caught it. He only fell further behind. We have already seen based on owners' reviews and timeslips that the M is a dog off the line. So if the G draws away at 120 mph plus, and the M can't get off the line, not sure that I would put my money on an M to close the gap in the next bunch of seconds.

Improviz

Hi, Jordon, welcome to the forum.

I'm not sure where you're getting 30 mph. The person who posted the video wrote that in the Gallardo race, they started in first gear at 60 km/h, which is 37.5 mph, while in the Viper race he wrote they started in second gear at 80 km/h, which is 50 mph. I quoted the threads directly above.

You can read this here:
http://www.6speedonline.com/forums/s...5&pagenumber=1

As to RPMs, I used data provided by fastsalons.com, which you can read here:
http://fastsaloons.com/cardetails.php?carlist=(134)

It gives max speeds and gears, and also gives you the mph/1000 rpm figures for each gear so that you can quickly calculate the rpm of the motor in a given gear at a given speed.

At 37.5 mph in first, this works out to 37.5/5.5 = 6,800 rpm, which can seen in the capture of the tach from the first Lambo video I posted above.

At 50 mph in second, it comes out to 50/8.3 = 6,000 rpm.

Cheers, and welcome again.

jordan

As you will find out,,I am a man of facts. I was thinking it was 30 mph. If he was running 6800 at 38 mph, he should have started out in 2nd! And the viper race was good for the M5 to be in second at that speed. And your figures are correct. Remember, I have not preff for types of cars...just fast ones...as they all are the best at something/type. IE...M5 on the track or highway is where this car shines, E55 1/4 in the sedan category. Z06 as far as sports car is the best bang for the buck.. I don't think much will touch it for a while. Here is what I found....to back up your numbers as they are right on brother.....but still say M5 in 2nd at that speed would have been better. But still would have lost at the top speed they only went. This proves
scratch is not correct about him being in 2nd at 55. Case close! Proof is what it's about....

Remember guys, this 1 M5's video is not the Gospel as we don't know all about the settings or car. I have seen some fast video of the M5 beating the Gallardo's and other things....Let's just hold out for a bit longer and we will see more races and track times to get a true idea of how fast the M is before we think it is slow and an easy win. Trust me, there are many a race I thought would be easy and lost, even to a freakin pick up truck. ALL new cars out should get 3 or 4 months of seasoning and track times/races before it goes in the AUTO BIBLE. I love the e55's, M5's, Vipers, ZO6's and even the Gallardo as they are all neck and neck and fun to drive.

Jordan...

I have been reading you all for a while, just never chimed in for the past 4 months. check out this photo I found, this vid and other have all been talked about. Seek info before doing the Math...it's faster and easier.

Improviz

Wow, where did you get that image?? Could've saved me a bunch of trouble if I'd have had that!!

Yeah, I agree about the bang for the buck (and for a lot more bucks in many cases!) of that Z06. Pretty amazing performance from that thing.

I do also think that the M is an amazing car, but I also think the AMGs are amzaing cars, and I get annoyed at the pooh-pooing of Mercedes by these trolls...

Anyway, thanks for the image!