znod

Just like Thumper's mother said. "If you can't say somethin nice about someone, then don't say nuthin at all."

das

FastCarFan:

Do not post in this thread any longer unless you have something to contribute to the technical topic. Thank you.

znod

Hi All:

I have done a shift-point analysis based on torque values from my Pro RR meter. Using these values should be superior to the more conventional form of analysis that is based on a dyno plot. The use of these values should be superior because one can take into consideration exactly what happens in each gear as a consequence of all forms of road-torque thievery, including rolling resistance and wind resistance. In making the analysis, I use what I call optimal shift-point theory--the conerstone of which is the idea that, in shifting to a higher gear, one should either minimize the road torque loss that occurs or maximize the road torque increase that occurs.

In making the analysis, I assumed that downshifts to lower gears will be proportional to what happens when the Step shifts manually?which is implicit in (1) through (3). For example, when shifting from 1st to 2nd, the Step, having shifted at 6,451 RPM, moves to 2nd at 4,481 RPM. Now, (4) through (6) assume that shifting is manual and that the shift from one gear to another is 50 RPM less than would have occurred via automatic shifting. Given that I have no idea what starting RPM is pertinent to, for example, 2nd gear under these conditions, I had to make an assumption. So, I made the proportionality assumption mentioned above. For example, I assumed that the starting RPM, for example, in second would be 4,446 RPM = 4,481(6,401 / 6,451). I have not attempted any kind of analysis that would show how sensitive my results are to this assumption.

The analysis implies that what happens in first gear is better under manual shifting (i.e., from comparing (1) with (4)). However, as inferred by comparing (2) with (5) and (3) with (6), what happens in second and third gears appears to be better if shifting automatically--particularly when shifting from third to fourth. Thus, this analysis yields mixed interences.

Bokke

I made some runs this afternoon and am very discouraged! The temp was 72F, humidity was 65%, altitude - 650ft and my best 0 - 60 run was 5.86 seconds. My 60 foot times were in the 2.10 to 2.15 range, but this time I was getting significant wheel spin in the shift to second gear. I am wondering if my tires "suck"...I had Michelin Pilots on my E39 M5 and don't recall getting as much wheel at the 1-2 shift, so I am convinced the Bridgestone's are inferior.....Oh, this was also with the charcoal filters removed. Z-man and G-man, do you get any wheel spin (DTC off) at the 1-2 shift?

I am also thinking, why did I go down this path?

OBTW, Das thanks for "unlocking" this tread, I think it is the most useful on this site.

Cheers,

znod

Hey man. Don't give up. Driving a manual is not easy. You may need to start making some weather and altitude adustments. Today's results very well may be better than you think. To do these adjustments, you will need to do a whole 1/4 mile (very carefully). Look at the difference in my 0 to 60 data for unadjusted versus adjusted in the first post of this thread. The differences in mine could correlate highly with the differences in your today's results and your earlier results. Don't be discouraged. And, and I get no wheel spin going to second on the 545i. You could get drag radials if you don't have 19" wheels. They would help tremendously. And, thanks for the vote of confidence for this thread. We don't want to lose you.

If you can get me your approximate dewpoint and barometer reading in your area for today, then I will do a somewhat inaccurate weather and altitude adjustment for your today's 0 to 60 time. We'll see how things look. You should get a better looking result.

znod

Hi Bokke:

I meant to say a bit more about your tires. I am not sure how many miles you have on them, but I had to replace my Z06 tires before 10k miles, but, of course they were relatively soft and sticky tires. And, believe it or not, I don't burn that much rubber in the Z06. When I got my g-meter, I tried some tests in the Z06, and I could get zero traction in either first or second. So, I decided on the drag radials because I try to minimize wheel spin. But, other relatively soft and sticky tires would have worked as well--at least when new.

You can get drag radials for the E60 in sizes 17" and 18". Running drag radials on the street works fine for me; however, on the frequently wet streets of Houston, I probably would feel differently. Those streets can get pretty slippery. I know; I grew up there--Houston/Bellaire.

grogan545

Hi Bokke,Its not possible to get any wheelspin with a step after first gear.The timing is retarded and the shift slow enough so that you can't even get a "chirp"on any of the shifts.This is my biggest complaint with the step.I am waiting for Dinan to come out with a trans program to allow more control and more agressive shifts for the step.Your times may be as Znod said due to weather condiitons.I had a 2.10 60' time recently but still managed a 5.32 sec 0-60.What are your 1/8 speeds ?They are a good indicator of if your horsepower is down.If your times are relatively slow but your 1/8 speed is good(80+)it would indicate traction problems.

Bokke

I had 2 runs late today - around 5pm CST.

NWS data from DFW, which is about 17 miles due west of me....
temp - 75.9F
dew pt - 59.0
barametric pressure - 30.08
altitiude - 625ft

0-80....9.87
0-70....7.92
0-60....5.90.....5.97
0-50....4.55.....4.60
0-40....3.32.....3.32
0-30....2.10.....2.10
0-20....1.25.....1.25
0-10....0.32.....0.33

1/8......9.37.....9.57
speed..76.0.....65.6

300ft...6.13.....6.15
60ft.....2.17.....2.17

HP.......328......323

...still getting wheel spin at the 1-2 shift Also, very frustrated that I cannot get my 60ft times down. I am convinced that a large part of the problem is my tires - this is my first, and last, set of Bridgestones. I will replace with the Michelins!

Still wanting to learn but getting very discouraged. All these years having a manual because it was quicker, and am thinking I should stick with the Step or SMG

Cheers,

znod

You are due for both weather and altitude correction improvements. Things should look at least somewhat better after making these adjustments. Unfortunately, the available adustment calculators don't work well for anythng but 1/4 results. I will use your data and get some approximate results for you--as mentioned before. It's 3 a.m. right now so I am going back to bed soon.

Still, even your first 1/8 mile speed looks too low. I think my GT2 reads low for 1/8 speeds, but who knows?

znod

Hi Bokke:

The following shows the significance of weather and altitute adjustments. Below is my better of two passes today. The weather and altitude adjustments turn what appears to be an uninspiring pass into my 3rd best after adjustment.

Altitude--1550'
Density Altitude--2008.5' (bigger than "altitude" because of unfavorable weather)

........................Unadjusted................ Adjusted
1/4 Speed.............103.000.................105.495
1/4 Time.................13.725...................13.4 08
0 to 60......................5.248....................4 .924
1/8 Speed...............81.900...................83.18 6
1/8 Time...................8.917.....................8 .698

I adjusted some of your first pass data from above for weather and altitude. I ignored the second pass because something looks wrong with it's 1/8 data--like you coasted through the 1/8.

Your density altitude is:

Air Temp 75.9 (?F)
Altimeter Setting 30.8 (in)
Dew Point 59 (?F)
Altitude 625 (Feet)
Density Altitude 1095.8 (feet)

Using your density altitude, I calculated the adjusted values below.

Corrected 1/8 Time: 9.262
Corrected 1/8 Speed 76.895

Below are my adjusted results from today calculated the same way. Note that they do not agree with the regression approach I use in getting adjusted values other than those for the 1/4. As said before, the NHRA- type adjustments appear to apply only to the 1/4.

"Adjusted" 1/8 Time: 8.711
"Adjusted 1/8 Speed: 83.884

I used both sets of my adjusted data to correct your adjusted data additionally. Here is what I came up with.

Bokke--Additionally Corrected 1/8 Time: 9.262 - (8.711 - 8.698) = 9.249
Bokke--Additonally Corrected 1/8 Speed: 76.895 - (83.884 - 83.186) = 76.197

Overall, I did not help much. But, at least what I have done shows that your first pass is better than it looks. And, not that there is no reason to be particularly secure with my SOP procedures for making your adjustments.

1/8 Time: 9.37 - 9.249 = .12 better
1/8 Speed: 76.197 - 76 = .197 better

Still not great though. Too much wheel spin/possibly bad tires is my assessment.