JBFMCAR

0-125 great race then first the M6 would pass and then the M5 would soon follow suit these cars a geared for the hwy and haul serious *** up top! The M6 pulls the SL65 on the HWY up top.

J 2OOI

Hey Marcus, just curious... what is your best 1/4 mile trap speed in the E55??

Hope all is well....

Improviz

Actually, the M5/M6 motors have smaller displacement than the 55k cars; they have 5.0L V10s vs 5.4L V8s. Why they win up high is because once the 55k cars hit fourth gear at 130 their torque multiplication drops off dramatically as their gear ratios are a compromise between performance and fuel economy, while the M cars are geared for max acceleration all the way up--and which is why they have to fill up with gas every 160 miles or so.

Doesn't bother me...don't get up that high enough to worry about it, frankly.

Brabus E55

I raced Vic once with his 65 and he smoked me pretty good

New2this

I don't know about a stage 1 E55, but I do know that a K4 E55 holds it own vs Renntech SL65 from a dig all the way up to the speed limiters..

My buddy has the K4 E55, and I had the RT SL65.. Tried several different times, and it was ALWAYS the same result...

Whichever car got the jump, was the car that stayed ahead, the whole way.

jangy

Its the SC. At some point, it stops pushing as hard and actually becomes a hindrance. Don't buy into all the gearing crap. Power is real, regardless of the gear you are in and that is what needs the multiplier. If not, all cars would have 10 gears and be faster than the E55. The Ms are faster because they are made that way. Their intake and exhaust is "geared" for 100 - 150mph blasts, whereas MB made the 55k to go 0 - 100.

NSX2NV

+8,000,000,001

Marcus Frost

I trapped almost 118mph bone stock, and with VRP550 I picked up ~30rwhp and ~50rwtq over stock. I have not been back to the track with the VRP550.

I dyno'd my SL65 but it had a bad IC pump, however the E55 would be very close to the 65 in hp (within 10%) and while the 65 would have the leg up on TQ, it has quite a few pounds over the 55 to contend with.

Not saying the E55 would win, but it would be a great race.

-m

Marcus Frost

Jangy,

I disagree, but on the premise that gearing is not the actual reason WHY the V10s pull on top, rather it ALLOWS them to take advantage of the way their engines were built. True to F1, as power is squeezed out of a motor with higher revs, it is also limited to that extra power within a more confined section of their rev band - hence the need for additional gears. In other words, if you took "x" engine which makes 250hp at a redline of 7k rpm, but then worked the engine to make 300hp at 8k rpm - you would ideally want gearing that allowed you to keep the engine in the higher rev band while going through them. If shifting from 5th-6th on this motor dropped you below the real power hand that would, obviously, hinder acceleration.

It would be great to see an E55 vs SMG M5 vs 6spd E60 M5 - it would clearly show the true story.

-m

Improviz

Both are correct. The gears are designed such that they keep the engine in its max power band from gear-gear, *and* give substantially higher torque multiplication than the E55 in the process.

We all know that the E55's horsepower is underrated. Dynos are in the 420 hp range, and from trap speeds alone vs. weight they're obviously up in the 530 range, if not higher. But let's use that....this means that since hp is directly proportional to torque, the torque would get scaled up by the same amount, giving 575 "true" peak torque.

This is 575/383 = 150% of the M5's max rated torque. Now, have a look at how much more torque multiplication the M5's gears give it than the E55's:
if you take the product of the gear*final drive for each cars' gears, you see that the BMW has a much higher degree of torque multiplication...*particularly* in the higher gears. In the lower gears, the advantage is substantially less, but starting in 4th gear the BMW has an enormous gearing advantage--and it shows:

Compared to E55:
gear E55 mult M5 mult % advantage
1 9.51 14.44 152
2 5.8 9.59 165
3 3.74 6.55 175
4 2.65 5.03 190
5 2.2 4.2 191

Notice that the advantage in gearing is negated by the E55's advantage in torque, until the third, and especially fourth gear.

The lower gears' advantage is probably negated somewhat by the forced induction on the E55, which allows the engine's response to give a very flat response, maximizing torque over the power band, while the M5's n/a motor will be a bit more peaky...but when the gearing gives 190% in fourth gear, that's a pretty big advantage to overcome.

jangy

Marcus, you bring up a great point and I'm definitely not arguing it. I guess my point is that I don't think the E55k would be much, if any, faster with more gears. As my car has gotten faster, getting air through the system is my #1 concern. I simply do not believe that there is enough air flow to run at top end. PERIOD. I don't even think it is close. I think we loose a CRAP LOAD of power up top simply because we run out of air. the drop off isn't small, it is HUGE.

Here is a test that i have done and maybe we can set something up like it. I did some 3rd and 4th gear pulls against an E63 a long time ago. In each scenario, he was in 1 gear taller than me (either his 4th or 5th). Each time, I spanked him below 3500 rpm and he walked me from about 4k rpm all the way through. That is when i started modding....

Improviz

It does. The loss of the extra gear and weaker gearing clearly hurts the M5 up high. If you look at the results from the C&D tests of the six-speed M5 and the SMG, it becomes apparent. For the six speed, the 0-100 tests are meaningless from zero, as they stated that the six-speed version's traction control intervened at launch where the SMG's didn't. but you can still use them to compare the 60-100, 60-150 and 100-150 times where TC wouldn't be a factor:

SMG:
0-60: 4.2
0-100: 9.4
0-150: 20.7

6 spd manual:
0-60: 4.7
0-100: 10.3
0-150: 23.4

60-100 split:
6 spd: 5.6
SMG: 5.2

60-150 split:
6 spd: 18.7
SMG: 16.5

100-150 split:
6 spd: 13.1
SMG: 11.3

Also, when C&D tested the E55 back in '03, they got:
0-60: 4.3
0-100: 9.9
0-150: 24.5

So its 60-100 split of 5.6 was the same as the six speed M5 and only 0.4 off the SMG, its 60-150 time of 20.2 is 1.5 sec. off the six speed's vs 3.7 off the SMG, and its 100-150 time of 14.6 is also 1.5 sec off the six-speed's, vs a 3.3 sec. gap vs the SMG. The six speed car starts drops 0.4 from 60-100 vs the SMG, and almost 2 more from 100-150.

So in both cases virtually all of the pickup came between 100-150 for the M5, and with the six speed it was cut in half. Both cars have the same final drive, but the gear ratios of the seven speed and six speed respectively are:
3.99/2.65/1.81/1.39/1.16/1.00/0.83
4.06/2.40/1.58/1.19/1.00/0.87

Percentages of six speed ratio to seven speed ratio, gears 1-6:
102%/91%/87%/85%/86%/87%

Third gear in the six speed starts at 73 mph and goes to 110, and fourth goes up to 146. The acceleration falls off directly with the torque multiplication. It's all in the physics.

jangy

I'm reading and learning...

Blownbenz

By the way what options are included on your 06 cls55 perf pkg?

Improviz

Do you mean options on the car itself, or are you asking what options are included in the 030 package?