grogan545

Right, your tire size might do the trick consistently for you.

I have changed my mind, maybe, about my agreement above. Here is something I posted once before. Check it out. Are you sure your tire sizes imply complete shifting after 60 MPH?

"Thus, with stock [sport package] wheels/tires, the starting shift points would be the same as the revised-for no-rounding values for my setup calculated below subsequently:

(5,346 / 6,500(33.99283975) = 27.96
(6,158 / 6,500)60.57698365) = 57.39

The atrocious ones I calculated earlier for my setup, but now without rounding, are:

(5,346 / 6,500(34.28769707) = 28.20
(6,158 / 6,500)61.10243456 = 57.89

Thus, my conlusions about starting shift points are independent of the wheel tire setup. Perhaps I should have seen this independence because of proportionality before calculating, but I did not."

Good morning. Please see the orange insert above. The calculations don't necessaryily imply anything about your car. But, I wonder if your tire sizes are that different from the stock sport package tires--used in the first two calculations. So, as mentioned, I wonder if your car really is doing all of its shifting after 60 MPH.

And, I know where to find your sweet spot instructions. Thanks. Finally, wow, if what you say holds up, then I will be looking forward to a less than 5 sec. average. Happy snow days.
[/quote]


I calculate my speed in second as follows:
tire dia-25.9"
25.9Xpi=81.37"
81.37/12=6.781'
6.781/3.38(rear ratio)=2.006'
2.006/2.34(2 gear)=.857'/rev
6158rpmX.857=5279.47'/minute
5279.47/5280=.9999
.9999X60=59.99 mph shift point in second gear for my car.

znod

Thanks g-man. We are getting ready to leave, come back, and leave again for much of the day. So, I'll be totally inactive after about 12:00 until maybe this evening. I am going to look at you calculations above and then compare them to the way I have been calculating such things.

Below are some old and new data. They pertain to only my best three runs with the Pro RR. The first two runs were presented above, but the third one is a new one. I used DS on this run--with good results, comparatively.

I wanted to get all possible comparisons out of the way before ditching the mods. Note that it looks to me like both my 0-30 and 0-60 times are being affected by shifting. Of course, shifting, per se, in this way, won't hurt 1/8 and 1/4 results unless my car is shifting early. Have you determined your starting shift RPM's? If you could do so, they might help us figure out for sure whos' 0 to 30/60 times are being affected by the Step's shifting. Also, importantly, I noticed, from the Pro RR, that both 60' and 330' occur at RPM dips right after a shift occurs. So, on my car, they too are being affected by Step shifting. Here are the data--which I don't have time to make completely pretty right now. Happy thinking.

Key:

NS = New Strip
N/S= North/South
D = D Mode
DS= DS Mode
P = Rro RR

After Dealer...............NS/S/D/P.......NS/N/D/P NS/S/DS/P
Pro RR..........................Test 6...........Test 7............Test 8........Average
1/4 Mile Time................13.774..........13.882........ ...13.810.........13.844
1/8 Mile Time..................8.940...........8.999....... ......8.971...........8.979
0-100...........................12.996..........13.3 55...........13.038.........13.221
0-90.............................10.566..........10. 821...........10.631.........10.732
0-80...............................8.698...........8 .874.............8.746...........8.817
0-70...............................7.000...........7 .123.............7.030...........7.083
0-60...............................5.300...........5 .384.............5.344...........5.365
0-50...............................4.039...........4 .091.............4.081...........4.078
0-40...............................2.941...........2 .980.............2.962...........2.965
0-30...............................1.766...........1 .808.............1.803...........1.793
0-20...............................1.005...........1 .035.............1.034...........1.022
0-10...............................0.318...........0 .327.............0.343...........0.324
1,000 Feet.....................11.565.........11.649.... .......11.599.........11.620
330 Feet.........................5.828...........5.865 .............5.856...........5.850
60 Feet...........................2.046...........2.0 68............2.069...........2.053
1/8 Mile Time..................8.940...........8.999....... ......8.971..........8.979
1/8 Mile Speed..............81.460..........80.740......... ..81.360........80.763
1/4 Mile Time................13.774..........13.882........ ...13.810........13.844
1/4 Mile Speed............102.290........101.700..........1 02.200......101.773
HP @ Speed
HP @ RPM.................235.1@5.79k..225.7@5.69k..232. 8@5.77k
Torque @ RPM...........250.7@4.48k..243.3@4.49k..249.6@4.54 k
Shift Points:
1st to 2nd--
RPM..............................6,264...........6 ,220..............6,216
Time............................1.770s.........1.7 04s.............1.710s
Speed.........................30.130..........28.7 70............28.970
2nd to 3rd--
RPM..............................6,216...........6 ,240..............6,228
Time.............................5.266...........5 .299............5.441s
Speed.........................59.840..........59.4 70...........60.480
3rd to 4th--
RPM..............................6,224...........6 ,212..............6,212
Time..........................11.839s........11.91 2s..........12.158s
Speed.........................95.370..........94.3 20...........96.490

Bokke

Did a couple of runs this morning:

Temp:40F
Hum: 27%
Wind: N25
Direction: East/West
DTC: off
launch RPM: 1,000 - 1,500

#1 #2 #3 #4 #5 Avg
0-80 9.90 - 8.92 - 9.60
0-70 7.82 7.53 7.20 7.50 7.55 7.52
0-60 5.70 5.55 5.55 5.52 5.58 5.58
0-50 4.37 4.30 4.35 4.25 4.27 4.31
0-40 3.30 3.32 3.38 3.20 3.27 3.29
0-30 1.97 2.00 2.10 1.93 2.00 2.00
0-20 1.20 1.20 1.33 1.15 1.20 1.22
0-10 0.37 0.35 0.50 0.35 0.35 0.38

1/8 9.30 9.20 9.17 9.15 9.20 9.20
75.90 76.2 79.9 77.2 76.8 77.2

300ft 6.02 6.00 6.08 5.95 6.00 6.01
60ft 2.13 2.15 2.25 2.10 2.15 2.16

HP -- 341 360 324 336 272

Had some traction issues on the first couple of runs as I think my tires were just to cold, so I did not list them. I did set the "speed limit" chime at 62mph so I would not shift into 2nd until I heard the chime. RPM seemed to be about 6,200. This seemed to help. As you can see my best-to-date (5.52) also has my best 60ft time (2.10). I am still getting wheel spin at launch - this is just going to take practice - as I think this is my key to better 0-60 times. Today I did get significant wheel spin shifting into 2nd - on one run the whole backend twitched to the right and I aborted the run

I might go and try a couple later today when the temp is supposed to be about 10 degrees warmer.

Cheers,

znod

Way to go Bokke. I notice that you are getting more consistent and that your times are coming down. Both of us appear to be sufferng in the 0-10 and 0-20 departments. Your suffering is lack of traction. I am not sure what I am "suffering" from. However, it looks to me like the Pro RR measures 0 to the lower speeds as being slower than does my GT2.

For example, below are my 0 - 10 and 0 -20 data after 20.01.00, but before my dealer reset. Even given the reset, there is no reason for my current 0 - 10 and 0 - 20 values to be so much "slower" than these except for the change in the meter. And, there is no way to say which data are closer to correct for sure. The only evidence I have suggesting that the new meter may be measuring me more accurately overall is that my 1/8 and 1/4 mile speeds now seem more consistent what others, including the mags, get/got for trap speeds.

0-20 0.98 0.97 1.02 0.95 0.95 0.95 0.92 0.98
0-10 0.28 0.27 0.30 0.28 0.25 0.20 0.28 0.28

Looking forward to more data. Take care.

znod

I looked at tirerack.com, and, for your tires, they give the same revs per mile as for mine--708. I see now that you said earlier that your car's speed is off by 2 MPH also. And, you are basing your above calculation on the 6,158 RPM value used in the following calculation--which is independent of tire size.

(6,158 / 6,500)61.10243456 = 57.89

It is my fault you used this value. I picked up the wrong values above. I think we should be using my "correctly" calculated value(s) of 5,308 and 6,170 given below (which actually would favor the point you are making).

(5,308 / 6,500(34.28769707) = 28
(6,170 / 6,500)61.10243456 = 58

But, if both of our revs per mile both are 807, I get the following:

There are 807 revs per mile given 275 / 30-19 (mine) rear tires = 225 / 50-17 (yours)
At 60 mph one would do a mile a minute, or 807 tire revs per minute.
If the effective rear-end is 1:1, then a mile a minute would take 807 engine RPM.
If the effective rear-end is 2.3322:1 (as below for 6th gear), then 60 MPH would take 2.3322(807)] = 1,882.0854 RPM
Given the above, it the car could turn 6,500, then its top speed would be 60(6,500 / 1,882.0854) = 207.216952

Thus, given the effective rear-end ratios below, and assuming that a 545i gets to 6,500 when shifting::

Top speed in 2nd gear would be 207.216952(2.3322 / 7.9092) = 61.10243456

However, from above, let's say a 545i only gets to 6,170 when shifting. Then:

Top speed in 2nd gear would be (6,170 / 6,500)61.10243456 = 58

545i Effective Rear-End Ratios:

1st gear--4.17 X 3.38 = 14.0946
2nd gear--2.34 X 3.38 = 7.9092
3rd gear--1.52 X 3.38 = 5.1376
4th gear--1.14 X 3.38 = 3.8532
5th gear--.87 X 3.38 = 2.9406
6th gear--.69 X 3.38 = 2.3322

So, what I am saying is that both of our zero to 60's may be affected by shifting.

grogan545

I looked at tirerack.com, and, for your tires, they give the same revs per mile as for mine--708. I see now that you said earlier that your car's speed is off by 2 MPH also. And, you are basing your above calculation on the 6,158 RPM value used in the following calculation--which is independent of tire size.

(6,158 / 6,500)61.10243456 = 57.89

It is my fault you used this value. I picked up the wrong values above. I think we should be using my "correctly" calculated value(s) of 5,308 and 6,170 given below (which actually would favor the point you are making).

(5,308 / 6,500(34.28769707) = 28
(6,170 / 6,500)61.10243456 = 58

But, if both of our revs per mile both are 807, I get the following:

There are 807 revs per mile given 275 / 30-19 (mine) rear tires = 225 / 50-17 (yours)
At 60 mph one would do a mile a minute, or 807 tire revs per minute.
If the effective rear-end is 1:1, then a mile a minute would take 807 engine RPM.
If the effective rear-end is 2.3322:1 (as below for 6th gear), then 60 MPH would take 2.3322(807)] = 1,882.0854 RPM
Given the above, it the car could turn 6,500, then its top speed would be 60(6,500 / 1,882.0854) = 207.216952

Thus, given the effective rear-end ratios below, and assuming that a 545i gets to 6,500 when shifting::

Top speed in 2nd gear would be 207.216952(2.3322 / 7.9092) = 61.10243456

However, from above, let's say a 545i only gets to 6,170 when shifting. Then:

Top speed in 2nd gear would be (6,170 / 6,500)61.10243456 = 58

545i Effective Rear-End Ratios:

1st gear--4.17 X 3.38 = 14.0946
2nd gear--2.34 X 3.38 = 7.9092
3rd gear--1.52 X 3.38 = 5.1376
4th gear--1.14 X 3.38 = 3.8532
5th gear--.87 X 3.38 = 2.9406
6th gear--.69 X 3.38 = 2.3322

So, what I am saying is that both of our zero to 60's may be affected by shifting.
[/quote]

You could be correct Z man.I got my data from the tire manufacturer info.My tire is listed at 25.9' dia.,and your tire is listed at 25.7' dia.Maybe Tirerack got lazy and thought this minor diff is insignificant.The real unknown on my part is at what exact rpm the 2 to 3 shift occurs.It is so close to 60 mph that it may or may not affect my 0-60 time.Your Pro RR meter is giving you real data.Just looking at my speedo & tach is not accuate enough.I think I mentioned before that both the speedo & tach have built in dampening so the needle does't swing wildley.I have quite a bit of experience in my occupation in dampening electronic signals(Industrial Automation).I deal with all kinds of signals from flowmeters and the like and it is always necessary to dampen(slow the response)them to prevent the readout from fluctuating.Therefore when we read 6000 on our tachs,the engine has already passed this point.I just don't know how much past.

cobradav

Well crap, I won't be adding to the body of knowledge for awhile. Finally finished swabbing the deck, clean up and load up the Gtech for trial run(s). Get to my selected spot and boy is it busy. Anyway get the thing calibrated, trial run for level set, and then a real run, but aborted when I sawa how bogged down I got. Tried another, and a little better but had to back off for traffic. Got turned around and the rains came and hard (only rain in last 7 days) so I was going to cruise home, stopping to get a serial to USB connector. About 10 minutes into the return trip all text disappears from meter (backlight still on). DC Adapter haas switch turn of and on and only backlight comes up, text never came back. Turned off, came home, plugged into AC and still no text (have backlight). Sent Telsa an email asking for RMA. Sh*t. Can't even test the download into PASS. It'll be at least two weeks before I'm back in the game as I leave for Seattle next week.

Oh, well what can I say. Not impressed with quality control to say the least.

znod

Very cool line of work. I knew that you had some sort of heavy technical/engineering background.

Anyway, I think what's below is about all we "know"--assuming that our cars are shifting at about the same times.

2nd to 3rd--
RPM.......................6,216.......6,090......6 ,216
Time.....................5.266s.....5.266s.....5.5 30s
Speed..................59.840......59.840....61.16 0

So, maybe both of us are affected totally--since 6,216 is right before RPM start to decrease. And, given this value, a starting shift value of 6,170 makes sense--which implies that it takes the step 46 (increasing) RPM (6,216 - 6,170) or .11 sec (see below) to do the 2-3 shift. Unfortunately, here is what we are up against in drawing conclusions based on the pertinent download from the Pro RR.

Secs...........Speed.............................. .RPM
5.2 273.74 59.44 0.285 187.3 162.5 6052
5.21 274.61 59.5 0.283 186.1 161.3 6057
5.22 275.48 59.56 0.281 185 160.3 6062
5.23 276.37 59.62 0.279 183.9 159.1 6067
5.24 277.24 59.68 0.277 182.8 158.1 6073
5.25 278.12 59.74 0.275 181.7 157 6078
5.26 278.99 59.79 0.273 180.6 155.9 6085
5.27 279.89 59.84 0.271 179.4 154.7 6090 Approximate time/speed 2-3 shift supposedly ended--at
5.28 280.74 59.89 0.269 178.2 153.5 6096....5.266 secs and 59.84 MPH.
5.29 281.64 59.95 0.267 176.9 152.3 6102
5.3 282.5 60 0.265 175.7 151.1 6108.........My 0 to 60 supposedly occurred here--5.30 secs.
5.31 283.4 60.06 0.262 174.3 149.7 6114
5.32 284.27 60.1 0.26 173.1 148.6 6119
5.33 285.16 60.15 0.258 171.8 147.3 6125
5.34 286.03 60.2 0.256 170.6 146.2 6131
5.35 286.92 60.25 0.254 169.4 145 6137
5.36 287.79 60.3 0.252 168.1 143.7 6143
5.37 288.69 60.35 0.25 167.2 142.8 6148
5.38 289.56 60.39 0.249 166.3 141.9 6154
5.39 290.44 60.44 0.247 165.4 141 6159
5.4 291.35 60.49 0.246 164.6 140.2 6164
5.41 292.23 60.53 0.245 163.9 139.5 6169....But, here is approximately 6,170 with 0 to 60.53 of
5.42 293.12 60.58 0.244 163.3 138.9 6174....5.41. Is it just coincidence that the difference here is
5.43 294 60.63 0.243 162.7 138.3 6179..... .11 (5.41 - 5.3) and above is .11 (6,216 - 6,170).
5.44 294.91 60.67 0.241 162.1 137.7 6184....Maybe my 0 to 60 really was 5.41. That would
5.45 295.79 60.73 0.24 161.5 137 6189......reconcile everything--except it would imply that the
5.46 296.68 60.78 0.239 161 136.5 6194.....whole 2-3 shift occurred after 60 MPH and, therefore,
5.47 297.56 60.83 0.238 160.5 136 6199.....my 0 - 60 could not be in 5.41. It's irrecon-
5.48 298.47 60.88 0.238 160.2 135.6 6204.....cilable.
5.49 299.38 60.94 0.237 160 135.4 6208
5.5 300.27 61 0.237 160 135.3 6210
5.51 301.15 61.05 0.237 160.1 135.3 6212
5.52 302.03 61.11 0.237 160.3 135.5 6213
5.53 302.94 61.16 0.238 160.8 135.8 6215 And, here is approximately 6,216 with 0 to 61.11 of 5.53.
5.54 303.82 61.2 0.238 161.2 136.4 6207 This is were RPM start to fall--after the shift.

The Pro RR could have cleared a lot of things up for us, but its inconsistency has just confused things more. Darn. So far I do have confidence in its timing ability, although I wonder why I am measured so slow for 0 to 10 and 0 to 20. It's just that my terminal speeds now seem reasonable. I am going to get my meter and play with it some more given the above values--as though I have not done so before. But, who knows, maybe I'll see something new?

znod

Hi cd:

That is a double or triple bummer. Bah Humbug. Really, I am sorry. Well, in the interim, please put your mind at work on the issue I've explained above. It is related to the A, B, C thing. If you think about this issue, then you should forget the A, B, C thing. Solving this problem solves A, B, C too.

Darn again!!!!! Keep in touch while you are gone.

grogan545

Very cool line of work. I knew that you had some sort of heavy technical/engineering background.

Anyway, I think what's below is about all we "know"--assuming that our cars are shifting at about the same times.

2nd to 3rd--
RPM.......................6,216.......6,090......6 ,216
Time.....................5.266s.....5.266s.....5.5 30s
Speed..................59.840......59.840....61.16 0

So, maybe both of us are affected totally--since 6,216 is right before RPM start to decrease. And, given this value, a starting shift value of 6,170 makes sense--which implies that it takes the step 46 (increasing) RPM (6,216 - 6,170) or .11 sec (see below) to do the 2-3 shift. Unfortunately, here is what we are up against in drawing conclusions based on the pertinent download from the Pro RR.

Secs...........Speed.............................. .RPM
5.2 273.74 59.44 0.285 187.3 162.5 6052
5.21 274.61 59.5 0.283 186.1 161.3 6057
5.22 275.48 59.56 0.281 185 160.3 6062
5.23 276.37 59.62 0.279 183.9 159.1 6067
5.24 277.24 59.68 0.277 182.8 158.1 6073
5.25 278.12 59.74 0.275 181.7 157 6078
5.26 278.99 59.79 0.273 180.6 155.9 6085
5.27 279.89 59.84 0.271 179.4 154.7 6090 Approximate time/speed 2-3 shift supposedly ended--at
5.28 280.74 59.89 0.269 178.2 153.5 6096....5.266 secs and 59.84 MPH.
5.29 281.64 59.95 0.267 176.9 152.3 6102
5.3 282.5 60 0.265 175.7 151.1 6108.........My 0 to 60 supposedly occurred here--5.30 secs.
5.31 283.4 60.06 0.262 174.3 149.7 6114
5.32 284.27 60.1 0.26 173.1 148.6 6119
5.33 285.16 60.15 0.258 171.8 147.3 6125
5.34 286.03 60.2 0.256 170.6 146.2 6131
5.35 286.92 60.25 0.254 169.4 145 6137
5.36 287.79 60.3 0.252 168.1 143.7 6143
5.37 288.69 60.35 0.25 167.2 142.8 6148
5.38 289.56 60.39 0.249 166.3 141.9 6154
5.39 290.44 60.44 0.247 165.4 141 6159
5.4 291.35 60.49 0.246 164.6 140.2 6164
5.41 292.23 60.53 0.245 163.9 139.5 6169....But, here is approximately 6,170 with 0 to 60.53 of
5.42 293.12 60.58 0.244 163.3 138.9 6174....5.41. Is it just coincidence that the difference here is
5.43 294 60.63 0.243 162.7 138.3 6179..... .11 (5.41 - 5.3) and above is .11 (6,216 - 6,170).
5.44 294.91 60.67 0.241 162.1 137.7 6184....Maybe my 0 to 60 really was 5.41. That would
5.45 295.79 60.73 0.24 161.5 137 6189......reconcile everything--except it would imply that the
5.46 296.68 60.78 0.239 161 136.5 6194.....whole 2-3 shift occurred after 60 MPH and, therefore,
5.47 297.56 60.83 0.238 160.5 136 6199.....my 0 - 60 could not be in 5.41. It's irrecon-
5.48 298.47 60.88 0.238 160.2 135.6 6204.....cilable.
5.49 299.38 60.94 0.237 160 135.4 6208
5.5 300.27 61 0.237 160 135.3 6210
5.51 301.15 61.05 0.237 160.1 135.3 6212
5.52 302.03 61.11 0.237 160.3 135.5 6213
5.53 302.94 61.16 0.238 160.8 135.8 6215 And, here is approximately 6,216 with 0 to 61.11 of 5.53.
5.54 303.82 61.2 0.238 161.2 136.4 6207 This is were RPM start to fall--after the shift.

The Pro RR could have cleared a lot of things up for us, but its inconsistency has just confused things more. Darn. So far I do have confidence in its timing ability, although I wonder why I am measured so slow for 0 to 10 and 0 to 20. It's just that my terminal speeds now seem reasonable. I am going to get my meter and play with it some more given the above values--as though I have not done so before. But, who knows, maybe I'll see something new?
[/quote]

Wow Znod the Pro RR gives a lot of data.I see what you mean about the inconsistantcy though.What I found interesting though is that it only took .11 seconds to complete the shift.I think I was confusing the power reduction before the shift with the actual start of the shift.I believe now that the power reduction occurs and then the shift occurs,not simultaneously.This gives the illusion that the shift takes longer than it actually does.
But how do we explain the other run where 6216 rpm is only 59.84?Again I will fall back on my limited knowledge of microprocessors from industry.A microprocessor does,t record all info simultaneously but records data in a serial fashion one after the other on a very fast scale.So it is not necessarily looking at speed and rpm at the same time.It could be that this device is looking at time & rpm more often than it is looking at speed,therefore sometimes the speed doesn,t seem to match the rpm,s.

Having said all that I may be full of crap.I just looked at the speed,time,and rpm of the 2 to 3 shift and noticed that the Pro RR has somehow mixed data between the 3 examples .The time & speed on the first listed data obviously belongs with the 6090rpm.Both 6216 rpm should have the same speeds,but i don't know how to reconcile the times.I think I am confusing myself.Am I making any sense to you Znod?