As much as I respect RennTechV12, I have to disagree with his theory, especially as stated in the very first post. According to that post, torque is the ONLY factor that determines the acceleration of a car. In that case, a Mack 16-wheeler should destroy a F1 car in a straight line race, because the truck produces enough torque to move a mountain and the F1 car, ~200lb-ft. But that doesn't happen.

Similarly if we took say, the Merc 350 engine + 7gtronic drivetrain, which produces roughly the same amount of torque as an F1 engine, and shoved it into an F1 car, it wouldn't win a race even against a Minardi.

This has been discussed FAR FAR FAR too many times, and torque isn't the only factor affecting acceleration.

Widest Michelin PS2s were the first things I did,lowered the suspension,put the LSD (why not standard from factory) and still had problems with electronics preventing any real driving.
The car has all this wonderful power but it's inaccesible except in a straight line.
I really do hope the new 6.3 will have a better power delivery and looking at the specs it sure sounds like it.

Torque and rpms are the only things that matter. Period. You can't have any hp without tq. HP is just a measure of tq at a given rpm. Torque and rpms are the main factors that affect acceleration weither it is by the engine or by torque multiplying gearing.

I am getting bored ****less by this continuing comparison with the M5.
It is now bordering on paranoia, so all those who are still worried about the stinking ugly M5, and whether they've made the right choice buying the E55, should go and buy the Bangle-bungle BMW and leave us all alone to enjoy our cars in peace. Amen.

Ahhhh yes! Those were the good old days. Another pops to mind: 190 E 2.3-16 v

Dude! You've already said it twice in your own post. The way to get a higher hp (as in the M5) with a modest torque is to increase the rpm, which BMW has done with the M5. So YOU CAN HAVE HP WITHOT TORQUE BY INCREASING THE RPM

No, you can't have hp without torque. HP is a measure of torque at a given rpm. What do you not understand? Here is the forumula again, HP = tq * RPM/5252. It's a very simple formula and it's the way you calculate hp, period! The M5 is able to make hp by keeping the torque high past 5252. If the E55 made more torque higher in the rpm range the hp would be greater too. If the E55 or M5 could keep tq stable to 10,000 rpm the engines would make way more power. That's how small engines with very little torque make big hp. They rev the **** out of them.

[QUOTE=BlownV8]No, you can't have hp without torque. HP is a measure of torque at a given rpm. What do you not understand? Here is the forumula again, HP = tq * RPM/5252. It's a very simple formula and it's the way you calculate hp, period! QUOTE]

You have shown a formula with TWO variables (torque, RPM) in a direct relationship (multiplication, not division) with hp. Any of the two variables, when altered will have a direct effect on the resultant hp.
You state " you can't have hp without torque." I guess I don't understand what you are trying to say. Granted, the M5 torque of 384 ftlbs is less than the E55s 500ftlb, but the M5 is carrying MORE hp (500vs. 469) How does this fact fit in to your logic/argument?

The M5 is able to keep that torque relatively high until the rev limiter kicks in. Let's say the M5 makes 351 lb-ft of tq at 7500 rpm. The engine would make (351 lb-ft * 7500 rpm)/5252 = 501.24 hp. Let's take an engine like the E55 that has around 429 lb-ft of tq at 6000 rpm. (429 lb-ft * 6,000rpm)/5252 = 490.1 hp. If the E55 could keep that 429 lb-ft of torque to 7,500 rpm, the motor would make (429 lb-ft * 7500)/5252 = 612 hp. Or conversely, if the M5 could keep the 384 lb-ft to 7500 rpm, it would make 548.36 hp.

So, you CAN have a higher HP, while not having the higher value in torque, it would just need to be peaking at a higher rpm

I'm an engineer with a degree in Physics, and I've done some consulting work (long ago) for some of the major auto companies. Your statement is only correct if you are talking about what torque the car puts to the drive wheels. I think that's probably what you mean. Otherwise, it's really the engine horsepower that determines acceleration.

What people are saying here, is that the torque to the rear wheels is not simply determined by the engine torque. The torque the car puts to the ground is mainly determined by the engine horsepower and the gearing.

If all you are talking about engine torque and horsepower, then acceleration is actually best determined using the horsepower. Any formula that estimates acceleration times will use horsepower, not torque as the primary variable. If you want to estimate your quarter mile times and trapspeeds, a reasonable formula is:

MPH = 225 (hp/weight)1/3 and ET = 6.290 (weight/hp)1/3

(1/3 indicates the cubed root)

This is a decent website with more detailed information:

http://www.stealth316.com/2-calc-hp-et-mph.htm

In Sport auto magazine a few months back there are some numbers posted for the Mercedes CLS55 AMG and the M5 tested in a shoot-out, so a side-by-side comparo on the same day:

0 - 40 km/h: CLS55: 1.5 sec / M5: 1.5 sec
0 - 60 km/h: CLS55: 2.3 sec / M5: 2.3 sec
0 - 80 km/h: CLS55: 3.2 sec / M5: 3.5 sec
0 - 100 km/h: CLS55: 4.7 sec / M5: 4.5 sec
0 - 120 km/h: CLS55: 6.0 sec / M5: 5.9 sec
0 - 140 km/h: CLS55: 7.9 sec / M5: 7.4 sec
0 - 160 km/h: CLS55: 10.2 sec / M5: 9.2 sec
0 - 180 km/h: CLS55: 12.3 sec / M5: 11.6 sec
0 - 200 km/h: CLS55: 15.4 sec / M5: 13.8 sec


Acceleration in 4th/5th gear (CLS55):
80 - 100 km/h: 3.1 / 4.6 sec
80 - 120 km/h: 5.9 / 8.7 sec
80 - 140 km/h: 9.0 / 12.8 sec
80 - 160 km/h: 12.0 / 16.8 sec
80 - 180 km/h: 15.8 / - sec

Acceleration in 4th/5th/6th/7th gear (M5):
80 - 100 km/h: 2.2 / 3.2 / 3.6 / 4.7 sec
80 - 120 km/h: 4.5 / 5.9 / 6.9 / 9.9 sec
80 - 140 km/h: 6.9 / 8.7 / 10.2 / 14.6 sec
80 - 160 km/h: 8.8 / 11.7 / 13.5 / 19.0 sec
80 - 180 km/h: 10.8 / 14.4 / 17.3 / 23.9 sec

Note M5 one gear higher still pulls the 55 from as low as 50mph. But of course in a racing situation bot driver are gonna stomp it or flick the paddles & get the lowest gear possible & then the M5 will win as it is a revver with high rpm power & more than enough torque for its gearing.

But as my post has proven, even in a low rev lugging contest the M5 pulls the 55 due to gearing.

Hey Impro, how you doing man? I'm postin this from an Internet Cafe in Italy bud!

In Response to Zumbalak
Zumbalak - There are some of us who live in places like South Florida where there is an absolute ABUNDANCE of short straights between stop lights and stop signs, and an absolute ABSENCE of any turns or twisties. For us, a BMW M5 would still be a wonderful car to own, make no mistake, but every E55 would still spank it on a daily basis.

For us to have any fun on the streets, and ability to stomp and squirt it from the lights and get up to speed instantly before hitting the brakes, is just about the only fun we are ever going to have with our cars, without leaving our state or taking it to the track.

I firmly beleive that the new M5 will be an ABSOLUTELY AWESOME car, but a bit wasted on me here in S. FL. And yes, if the videos are anything to go by, it will pull away from my E55 at higher speeds, but generally our bragging rights in S FL are won at speeds under 80 mph.

And as for tracking my car, this is something I have done, but it is not what I bought my E55 for, and while it is still a car than can be tracked, if tracking is what you really want to do with your car, you are not going to be buying an E55 or an M5 - just my $0.02!

Sisati

I think the M5 limits at 8200 RPM. When comparing torque with hp, I think you guys are probably saying the same thing. You can't have hp without torque, but holding torque constant, the remaining variable is RPM. So, make an engine that revs higher will give you more hp; that's the BMW and F1 concept. MB is moving in that direction with the e63, except it increases displacement to also give it more torque. It can't rev as high as the v10 M5, but it has more torque to give it more hp. In the end, the 6.2L v8 makes about the same hp as the bmw v10. They do the same thing in different ways.

It should be interesting to see the results. I assume it's easier to race with more torque because if you're caught in the wrong gear, it won't slow you down too much because of the low-end torque. Whereas, if you're in the wrong gear with the v10, you're left in the dust. With the bmw SMG, it's hard to screw up and put yourself in the wrong hear, but it's possible. I could be wrong, but that's what I've been reading.

Actually, I'm not so sure about your implicit characterization of AMG drivers...

Being that the AMG cars are (possibly excepting the SLK and C) monumentally heavy, fairly ponderous (by comparison, taking your p.o.v.) cars, I'd suggest it takes a better driver to harness and shepherd all that power, as opposed to the BMW, which I've never driven but which is said to be all about killer handling; wouldn't it be tougher by yours and others' logic (and therefore require the better driver) to handle with aplomb the car that "anyone can drive in a straight line"?

Apparently not, huh.

I have to agree; the M5 sounds like it'll be great if you live on one of those "switchback mountains" they always use in car commercials, or possibly up in the hills in LA or the bay area or the like. On the other hand, the 'straight line' lower-revving power delivery of the e55 really seems tailor made for the American driving style -- straightaways/traffic light drag racing/endless interstates, and of course, the German autobahns.

It sounds like a taste and application-specific thing to me, and more "apples to oranges" each time i think about it.

That said, for as bizarrely "off" as the 5-series' interior looks, I checked out the wagon a couple of months ago and was surprised at how well thought-out it is: everything (arm rests, etc.) looks edgy and odd, but fits right under your body like the car was designed around a mannequin. Quite impressive, in a "she's not the best-looking so she tries harder" kind of way.

v

Is there a video of the e60 caught in the wrong gear while still pulling on the e55 that I haven't seen? What if it was up against an e63 and it was in the wrong gear? I don't want to hypothesize, but generally speaking, it's going to be tough to catch up to an e63 in the wrong gear.

Apparently not huh?

Exhibit A:

Acceleration in 4th gear (CLS55):
80 - 100 km/h: 3.1 sec
80 - 120 km/h: 5.9 sec
80 - 140 km/h: 9.0 sec
80 - 160 km/h: 12.0 sec
80 - 180 km/h: 15.8 sec

Acceleration in 5th gear (M5):
80 - 100 km/h: 3.2 sec
80 - 120 km/h: 5.9 sec
80 - 140 km/h: 8.7 sec
80 - 160 km/h: 11.7 sec
80 - 180 km/h: 14.4 sec

Exhibit B:

Acceleration in 5th gear (CLS55):
80 - 100 km/h: 4.6 sec
80 - 120 km/h: 8.7 sec
80 - 140 km/h: 12.8 sec
80 - 160 km/h: 16.8 sec
80 - 180 km/h: - sec

Acceleration in 6th gear (M5):
80 - 100 km/h: 3.6 sec
80 - 120 km/h: 6.9 sec
80 - 140 km/h: 10.2 sec
80 - 160 km/h: 13.5 sec
80 - 180 km/h: 17.3 sec

Great, Mr. Magazine is back. October Evo - M5 1/4 in 13.2 @ 116. I know, I know. Run on a gravel trap with 800 lbs of ballast, a full tank, carrying the Redskins' offensive line in p400 mode. Magazines mean squat.

Still waiting for them to show up at a track stateside. Any month now.

Out of curiosity, (seriously) what RPM is an M5 running in 4th gear at 80 kph? 5,000?

YEah Enzom, you sound like a typical sore loser. See plenty of them at the track. Catch a wake up or go back to school. A car with more HP that weighs less will SURPRISE SURPRISE be faster. If you can't comprehend that then there's no need for any further discussion from your part. Just sit in the corner & tell everyoen how good you are at kicking butt.

[QUOTE=enzom]Magazines mean squat.
[QUOTE]

And another thing. Great to say magazines mean squat when the results aren'tin your favour. I bet if the results were the other way around you'd change your tune.

So instead of magazines you think on the road encounters are more scientific? Hell anything can happen on the road man. Doesn't mean jack. But if you want on the road encounters I can post some videos of M5's whooping E55's. There's even a video of a stock M5 running away from a chipped E55. There's also videos of M5's passing 575 Ferrair's, 911 turbos, etc. PLEASE tell me you want the link wiseguy.

The problem is that your E55 block can't tolerate such high RPM.

You are talking about mathmatical calculation then actual performance of the engine, which is complete a$$ talk.

No. AMG is so soft with agressive ESP, you will never approach the limit that BMW M provides you in base car. For example, the M5 allows you to pull over 1G on skidpad, the E55 only pulls mid 0.8.

Plus, with M5 you have to be good with gearing selection and timing of gas pedal. Even though there is SMG, it is still a manual car. Hence selection of gear timing is very critical in getting more out of M5.

That's why M5 will require more skilled driver to max its potential than the E55.

The E55 is never designed to be a sports sedan. It is a great cruiser with insane straightline power, which really does not require an excellent driver.

Who told you the M5 pulls over 1.00g on the skidpad??