BMW unveils special edition E60 M5 CSL with 580hp!

[baloo]

Originally Posted by K-1

To make a point, you'd have to scale that to real life. You also need to watch your multiplicand/multiplier. In this case, increasing the "gallons carried" (torque, I assume) has a greater effect on total through-put than increasing the "trips per hour" (RPM).

4 * 20 = 80
4 * 21 = 84
5 * 20 = 100

Increasing the RPM by 10% has the same effect as increasing the torque by 10%. Adding 1 to both numbers is nonsense because the units are completely arbitrary.

[K-1]

Originally Posted by baloo

Increasing the RPM by 10% has the same effect as increasing the torque by 10%. Adding 1 to both numbers is nonsense because the units are completely arbitrary.

Yet, you used those same arbitrary units to support your argument...

[baloo]

Originally Posted by K-1

1200-6200 is above 400 lb-ft. Extrapolating out past 7000 is also above 400 lb-ft. Given that, the CTS-V is overpowering the M5 SE over the vast majority of the rev range. All else being equal, CTS-V (i.e. torque) wins.

That's not how it works. If an engine revs 33% higher, you can gear it 33% shorter, which means the M5 only needs 300 ft-lb to put the same torque to the wheels.

I can produce 1000 ft-lb with a set of pedals and a suitable gearbox, but that doesn't mean I make more power than a CTS-V.

[baloo]

Originally Posted by K-1

Yet, you used those same arbitrary units to support your argument...

No, the units and the absolute numbers are irrelevant. The point is, power is a product of rpm and torque. One factor is as important as the other. Increase either by 10% and the power increases by 10%.

Adding 1 to the numbers really serves no purpose at all, because I could have chosen milliliters instead of gallons and trips per minute instead of trips per hour.

[K-1]

Originally Posted by baloo

No, the units and the absolute numbers are irrelevant. The point is, power is a product of rpm and torque. One factor is as important as the other. Increase either by 10% and the power increases by 10%.

Adding 1 to the numbers really serves no purpose at all, because I could have chosen milliliters instead of gallons and trips per minute instead of trips per hour.

I never said RPM wasn't important. Torque and where it happens in the RPM band is what's important to acceleration. You guys then brought out the red herring of gearing, traction, etc. All else equal, if I'm 150 lb-ft above you from 1200-6200 RPM, it doesn't matter if you can run to 8400RPM. If you can provide mathematical proof to the contrary, I'd love to see it, so I know if I'm just talking out of my ass.

The CTS-V's gear ratios are as follows:
First: 2.660
Second: 1.780
Third: 1.300
Fourth: 1.000
Fifth: 0.800
Sixth: 0.630
Reverse: 2.900
Final Drive Ratio: 3.730

[baloo]

Originally Posted by K-1

I never said RPM wasn't important. Torque and where it happens in the RPM band is what's important to acceleration. You guys then brought out the red herring of gearing, traction, etc. All else equal, if I'm 150 lb-ft above you from 1200-6200 RPM, it doesn't matter if you can run to 8400RPM. If you can provide mathematical proof to the contrary, I'd love to see it, so I know if I'm just talking out of my ass.

Gearing is absolutely not a red herring, it's crucial.

Look, you could put a 2:1 reduction gear on the M5's crank and you'd have an engine that makes 800 ft-lb and redlines at 4125 rpm. According to your logic it would obviously be faster than the CTS-V, because it doesn't matter if you can run the CTS-V to 6200 rpm, the M5 is 300 ft-lb above it from 500-4125 rpm.

Do you see why this doesn't work?

[K-1]

Originally Posted by baloo

Gearing is absolutely not a red herring, it's crucial.

Look, you could put a 2:1 reduction gear on the M5's crank and you'd have an engine that makes 800 ft-lb and redlines at 4125 rpm. According to your logic it would obviously be faster than the CTS-V, because it doesn't matter if you can run the CTS-V to 6200 rpm, the M5 is 300 ft-lb above it from 500-4125 rpm.

Do you see why this doesn't work?

Your "crucial" alteration doesn't play within the confines of "all else being equal."

[baloo]

Originally Posted by K-1

Your "crucial" alteration doesn't play within the confines of "all else being equal."

That's the point. All else is not equal and you need to account for the higher rev range.

[K-1]

Originally Posted by baloo

That's the point. All else is not equal and you need to account for the higher rev range.

That's exactly my comparison. Different torque ratings, the one with lower torque revs higher. Which one wins?

[baloo]

Originally Posted by K-1

That's exactly my comparison. Different torque ratings, the one with lower torque revs higher. Which one wins?

The one with the highest power output over the rev range you're using.

[AMERICA 123]

The CTS -V is alive and well and is still the king of the hill.


From the lead article -

According to Autocar, official power and torque figures have not been released but Biermann hints the output peaks at “around 580bhp and close to 400lb ft”.

That’s up from 407bhp and 348lb ft with the standard M5. No performance claims have been made for the powered-up-and-pared-down M5, but Biermann says it is “comfortably faster the standard M5’s 4.1sec 0-100km/h”.

As part of the car's weight savings diet (which shaves approximately 50kg off the standard M5's 1830kg weight), the roof is now carbon fiber, which lowers the car's center of gravity for increased handling.

The interior has been stripped down for carbon fiber backed race seats up front and the rear seats were removed.

In terms of its suspension the new M5 remains close to the standard specification. “We’ve altered the mapping of the variable dampers but the geometry remains the same,” says Biermann.

As confirmed to Autocar, the new one-off M5 it has already lapped the Nurburgring in the hands of long-time BMW race driver, Claudia Huertgen, in under eight minutes, making it some 20sec faster around the legendary German circuit than the standard M5.

“It’s a lot gutsier than the standard M5,” says Huertgen, who this year drove the new Alpina M6 GT3 race car in the FIA sportscar championship.

“You can sense the added drive out of corners. There’s more bottom end shove. I’m pulling over 180mph under the bridge at the Doettinger Hohe [the fastest point of the track]."

As desirable as this car may be to all of us however, this car remains a one-off and there are no plans for production.

[ptviperz]

Originally Posted by K-1

Why does "my" engine have to stop at 5000RPM?

What's the redline? 5800 RPM? I have no idea but my last LS1 redlined at 5700-5800 I believe. It's a far cry from 8400 RPM

Torque originates at the engine - of course it's important! Engine torque * gear multiplication = wheel torque.

The acceleration that you get for a given amount of power decreases as the vehicle speed increases, yet, at any point in time, acceleration is proportional to power, and depends as much on engine speed as on engine torque.

[Xenon]

Originally Posted by K-1

Look at the differential in HP and TQ numbers. That's Honda-esque (in reference to the S2000 and Civic Si). Granted 400 ft-lb is a lot, but I'd rather have 580hp and nearly that in torque. Contrast those numbers with the CTS-V: 556hp, 551 lb-ft. If this new M5 isn't faster around the 'Ring (we'll see), then what's the point

Nope, no 3.5L V6 here. The '09s dropped the second V6. My (wife's) XE is the uber-smooth, uber-efficient 2.4L + 6-speed. Not that it matters one iota with respect to the M5's engine. But hey, if you can't attack the argument, attack the person, right?

Which means absolutely nothing, but thanks for playing.

The only reason I pointed that out is because you scoffed at 400ft-lbs of torque....That's a lot of power to scoff at, either way you look at it.

[Xenon]

Originally Posted by baloo

The higher an engine revs, the bigger the difference between horsepower and torque. Not because torque goes down but because horsepower goes up. In the end it's pretty much irrelevant because torque at the wheels is what moves a car, and an engine that makes 30% less torque, revs 30% higher and runs a 30% steeper final drive puts the same torque to the ground.

The only difference between 400ft-lb/550hp and 600ft-lb/550hp is the position of the tach needle and the noise the car makes.

For horsepower you're correct. For torque, the only way you are getting a significant increase on torque is by increasing displacement. Raising the redline on a car will give marginal increases of torque at best.

Originally Posted by K-1

Your "crucial" alteration doesn't play within the confines of "all else being equal."

Gearing is a crucial part of the drivetrain. You can't have "equal gearing" just from the fact that no engine is going to have the exact same optimal points as another. If you had equal gearing on both of the cars, one will probably suffer from it.