Hi Znod ,read your last 2 posts,very interesting info regarding your 1/4 times.I believe they can be verified on an NHRA strip.
Just a note on the data you compiled on my runs.I incorectly entered a 0-60 time of 5.05 on my S run.It should have been 5.17 sec.Don't know if changes much,but I thought it worth mentioning.
After all our bantering back & forth with our data I observed the following:
1-Your 60' times are consistantly better than mine.I can think of several reasons for this.You have better tires(michelins probably wider than my 225's).Lighter weight.Your 12" rollout vs my 10"(not a big diff as the diff is after already moving 10").
2-Your 330 times also faster on average due to lead you got at 60'.
3-Ditto for 1/8 mile
I believe my" times to speed "advantage is due to my test road,although even if I take average speed for N & S runs they still appear to be faster than yours.Could be your test road has a slight upgrade in the direction your testing.The time differences at higher speeds(above 60)on an upgrade are more pronounced.
I know from experience it is difficult to see a slight grade.
I know most readers probably don't believe we can get better results than the car mag "experts"but they only spend a few hours on acceleration testing and the cars are usually new with few miles on them.after a good break in and much time perfecting our method I find it hard to believe we can't do better than the "experts"
Seems to be a lot of readers to our conversations but no joiners.
Oh and that racer would be Eddie Hill.
I thought I wound't hear from you for 10 days but it looks like you can't stay away that long.Have a safe trip back home.
[/quote]
I changed my spread sheet for the 5.17 value. I see now that you mentioned your mis-post earlier. I will post my final analytical findings after getting home and linking the graphs. The change to 5.17 made only a small difference in the "paterns."
[/quote]Hi grogan:

In addition to assuming .6, I also made formula calculations for .55 and .65. The formula's results are rather insensitive to such changes also. Given the assumptions below, my predicted times range from 13.35 to 13.55 with the most likely values, IMO, falling in the range of 13.41 and 13.50.

55%
103 mph 104 mph 105 mph
80.50 80.50 80.50
55%
103 mph 104 mph 105 mph
82.00 82.00 82.00

60%
103 mph 104 mph 105 mph
80.50 80.50 80.50

60%
103 mph 104 mph 105 mph
82.00 82.00 82.00

65%
103 mph 104 mph 105 mph
80.50 80.50 80.50

65%
103 mph 104 mph 105 mph
82.00 82.00 82.00

Your formula is likely to be quite robust, I think.
[/quote]
Here are the final data sets for the graphs that I will post eventually.

Auto Mag Data:

Datum/Mag1/Mag2/Mag3/Ave/Change

0-90 10.90 11.00 10.95 2.18
0-80 8.90 8.40 9.00 8.77 1.62
0-70 7.10 7.20 7.15 1.78
0-60 5.40 5.20 5.50 5.37 1.32
0-50 4.00 4.10 4.05 1.15
0-40 2.80 2.90 3.00 2.90 1.15
0-30 1.60 1.90 1.75 0.65
0-20 1.10 1.10 1.10
0-10
0-0 0.00

Znod Data:

Datum/Znod Test 1/Znod Test 3/Znot test 4/Ave/Change
1/8 Mile Speed 80.40 80.50 80.50 80.47
1/8 Mile Time 8.78 8.71 8.71 8.73 0.06
0-80 8.72 8.65 8.65 8.67 1.88
0-70 6.82 6.75 6.82 6.80 1.65
0-60 5.14 5.07 5.22 5.14 1.27
0-50 3.89 3.82 3.92 3.88 1.07
0-40 2.82 2.76 2.83 2.80 1.11
0-30 1.72 1.65 1.70 1.69 0.74
0-20 0.97 0.89 1.00 0.95 0.66
0-10 0.32 0.25 0.30 0.29 0.29
0-0 0.00

grogan Data--Test 3 Included Only Once:

Datum/grogan Test 1/Grogan Test 2/Grogan Test 3/Ave/Change
1/8 Mile Speed 82.10 82.60 80.60 81.77
1/8 Mile Time 8.75 8.75 8.83 8.78 0.57
0-80 8.12 8.05 8.45 8.21 1.59
0-70 6.55 6.52 6.78 6.62 1.55
0-60 5.03 5.00 5.17 5.07 1.22
0-50 3.83 3.83 3.88 3.85 1.04
0-40 2.80 2.83 2.80 2.81 1.04
0-30 1.73 1.85 1.73 1.77 0.75
0-20 1.02 1.05 1.00 1.02 0.69
0-10 0.35 0.33 0.33 0.34 0.34
0-0 0.00

grogan Data--Test 3 Included Twice:

Datum/grogan Test 1/grogan Test 2/grogan Test 3/grogan Test 3/Ave/Change
1/8 Mile Speed 82.10 82.60 80.60 80.60 81.48
1/8 Mile Time 8.75 8.75 8.83 8.83 8.79 0.52
0-80 8.12 8.05 8.45 8.45 8.27 1.61
0-70 6.55 6.52 6.78 6.78 6.66 1.57
0-60 5.03 5.00 5.17 5.17 5.09 1.24
0-50 3.83 3.83 3.88 3.88 3.86 1.05
0-40 2.80 2.83 2.80 2.80 2.81 1.05
0-30 1.73 1.85 1.73 1.73 1.76 0.74
0-20 1.02 1.05 1.00 1.00 1.02 0.68
0-10 0.35 0.33 0.33 0.33 0.34 0.34
0-0 0.00

C6 Corvette Data:

Datum/C6 Vette/Change

0-90 8.20 1.40
0-80 6.80 1.40
0-70 5.40 1.10
0-60 4.30 1.00
0-50 3.30 0.80
0-40 2.50 0.70
0-30 1.80 1.80
0-20
0-10
0-0 0.00

 

Hi Znod ,read your last 2 posts,very interesting info regarding your 1/4 times.I believe they can be verified on an NHRA strip.
Just a note on the data you compiled on my runs.I incorectly entered a 0-60 time of 5.05 on my S run.It should have been 5.17 sec.Don't know if changes much,but I thought it worth mentioning.
After all our bantering back & forth with our data I observed the following:
1-Your 60' times are consistantly better than mine.I can think of several reasons for this.You have better tires(michelins probably wider than my 225's).Lighter weight.Your 12" rollout vs my 10"(not a big diff as the diff is after already moving 10").
2-Your 330 times also faster on average due to lead you got at 60'.
3-Ditto for 1/8 mile
I believe my" times to speed "advantage is due to my test road,although even if I take average speed for N & S runs they still appear to be faster than yours.Could be your test road has a slight upgrade in the direction your testing.The time differences at higher speeds(above 60)on an upgrade are more pronounced.
I know from experience it is difficult to see a slight grade.
I know most readers probably don't believe we can get better results than the car mag "experts"but they only spend a few hours on acceleration testing and the cars are usually new with few miles on them.after a good break in and much time perfecting our method I find it hard to believe we can't do better than the "experts"
Seems to be a lot of readers to our conversations but no joiners.
Oh and that racer would be Eddie Hill.
I thought I wound't hear from you for 10 days but it looks like you can't stay away that long.Have a safe trip back home.
[/quote]
I changed my spread sheet for the 5.17 value. I see now that you mentioned your mis-post earlier. I will post my final analytical findings after getting home and linking the graphs. The change to 5.17 made only a small difference in the "paterns."
[/quote]Hi grogan:

In addition to assuming .6, I also made formula calculations for .55 and .65. The formula's results are rather insensitive to such changes also. Given the assumptions below, my predicted times range from 13.35 to 13.55 with the most likely values, IMO, falling in the range of 13.41 and 13.50.

55%
103 mph 104 mph 105 mph
80.50 80.50 80.50
55%
103 mph 104 mph 105 mph
82.00 82.00 82.00

60%
103 mph 104 mph 105 mph
80.50 80.50 80.50

60%
103 mph 104 mph 105 mph
82.00 82.00 82.00

65%
103 mph 104 mph 105 mph
80.50 80.50 80.50

65%
103 mph 104 mph 105 mph
82.00 82.00 82.00

Your formula is likely to be quite robust, I think.
[/quote]
Here are the final data sets for the graphs that I will post eventually.

Auto Mag Data:

Datum/Mag1/Mag2/Mag3/Ave/Change

0-90 10.90 11.00 10.95 2.18
0-80 8.90 8.40 9.00 8.77 1.62
0-70 7.10 7.20 7.15 1.78
0-60 5.40 5.20 5.50 5.37 1.32
0-50 4.00 4.10 4.05 1.15
0-40 2.80 2.90 3.00 2.90 1.15
0-30 1.60 1.90 1.75 0.65
0-20 1.10 1.10 1.10
0-10
0-0 0.00

Znod Data:

Datum/Znod Test 1/Znod Test 3/Znot test 4/Ave/Change
1/8 Mile Speed 80.40 80.50 80.50 80.47
1/8 Mile Time 8.78 8.71 8.71 8.73 0.06
0-80 8.72 8.65 8.65 8.67 1.88
0-70 6.82 6.75 6.82 6.80 1.65
0-60 5.14 5.07 5.22 5.14 1.27
0-50 3.89 3.82 3.92 3.88 1.07
0-40 2.82 2.76 2.83 2.80 1.11
0-30 1.72 1.65 1.70 1.69 0.74
0-20 0.97 0.89 1.00 0.95 0.66
0-10 0.32 0.25 0.30 0.29 0.29
0-0 0.00

grogan Data--Test 3 Included Only Once:

Datum/grogan Test 1/Grogan Test 2/Grogan Test 3/Ave/Change
1/8 Mile Speed 82.10 82.60 80.60 81.77
1/8 Mile Time 8.75 8.75 8.83 8.78 0.57
0-80 8.12 8.05 8.45 8.21 1.59
0-70 6.55 6.52 6.78 6.62 1.55
0-60 5.03 5.00 5.17 5.07 1.22
0-50 3.83 3.83 3.88 3.85 1.04
0-40 2.80 2.83 2.80 2.81 1.04
0-30 1.73 1.85 1.73 1.77 0.75
0-20 1.02 1.05 1.00 1.02 0.69
0-10 0.35 0.33 0.33 0.34 0.34
0-0 0.00

grogan Data--Test 3 Included Twice:

Datum/grogan Test 1/grogan Test 2/grogan Test 3/grogan Test 3/Ave/Change
1/8 Mile Speed 82.10 82.60 80.60 80.60 81.48
1/8 Mile Time 8.75 8.75 8.83 8.83 8.79 0.52
0-80 8.12 8.05 8.45 8.45 8.27 1.61
0-70 6.55 6.52 6.78 6.78 6.66 1.57
0-60 5.03 5.00 5.17 5.17 5.09 1.24
0-50 3.83 3.83 3.88 3.88 3.86 1.05
0-40 2.80 2.83 2.80 2.80 2.81 1.05
0-30 1.73 1.85 1.73 1.73 1.76 0.74
0-20 1.02 1.05 1.00 1.00 1.02 0.68
0-10 0.35 0.33 0.33 0.33 0.34 0.34
0-0 0.00

C6 Corvette Data:

Datum/C6 Vette/Change

0-90 8.20 1.40
0-80 6.80 1.40
0-70 5.40 1.10
0-60 4.30 1.00
0-50 3.30 0.80
0-40 2.50 0.70
0-30 1.80 1.80
0-20
0-10
0-0 0.00
[/quote]

Hello Znod.You asked why 225 tires on my car.That is the standard tire for a 545I without the sport package.

Very interesting info(at least for you & I).As you noted the assumed values used after the 1/8 don't have a large effect on 1/4 elapsed times.This is because we are already going more than 80mph(more than 117'/sec)after the first 1/8.It is a knowned fact in drag racing that the 60' time has more to do with your eventual time than anything that happens after the first1/8(unless you blow your engine!!)

I am working on a "virtual" race between our cars.I'll average my best N & S runs and use the figures for my run,and use your best run #'s.I will post the results either later today or tomorrow.

ps I think it will be close

 

Hi grogan:

Your race results will be fun to see. I forgot, or maybe did not know that your car is sans the sport package. So, you have a slightly lower rear-end ratio than me, and your car would be somewhat lighter than a sport package car (at least because not sport package and its heavier wheels and maybe heavier fires)--maybe compensating for my lighter than stock wheels and tires. I decided to convert my graphs to JPEG images and am attaching them to subsequent replies because the forum software is behaving strangely. Enjoy, and post back if you have questions.

I will have to try to attach the graphs later. Who knows what is going on with the forum software. Sometimes the images attach and sometimes they don't. They seem to be right sized, but I may have to "shrink" them. OK, now I have tried "shriinking" them and still am having problems. I will try again in London or after arriving at home.

 

Hello again Znod
I was about to mention the weight diff between sport & non sport packages.It may cancel out any weight advantage you may have had.I checked specs on axel ratio,I believe it is the same for all steps.(3.38).the 6 speed manual is 2.93.
OK here goes with the "virtual"race.
-----------Znods best---------Grogans best ave(N&S)----------Time diff------Lead
60' 1.91 2.025 .115 sec Z by 5.57'
330' 5.68 5.75 .07 sec Z by 6.53'
1/8 8.71 8.79 .08 sec Z by 9.5'
1/4 13.467 13.48 .013 sec Z by 2.00'
Congratulations!!!
I calcuated the lead and by how many feet as follows:
Approximate speed converted to feet/sec at a given distance(33mph at 60'=48.4'sec)
multiply the feet/sec by the time diff(48.4X .115=5.57')
I used 33 mph at 60',63.6mph at 330',81mph at 1/8.For the 1/4 mile times I used my formula previously mentioned but used 1.5mph higher for Grogan as it looks like even my ave speed increases over yours after the 1/8.
O course their are many variables,road,weather reaction times etc.but based on our respective data you are the winner!!

 

Hello again Znod
I was about to mention the weight diff between sport & non sport packages.It may cancel out any weight advantage you may have had.I checked specs on axel ratio,I believe it is the same for all steps.(3.38).the 6 speed manual is 2.93.
OK here goes with the "virtual"race.
-----------Znods best---------Grogans best ave(N&S)----------Time diff------Lead
60' 1.91 2.025 .115 sec Z by 5.57'
330' 5.68 5.75 .07 sec Z by 6.53'
1/8 8.71 8.79 .08 sec Z by 9.5'
1/4 13.467 13.48 .013 sec Z by 2.00'
Congratulations!!!
I calcuated the lead and by how many feet as follows:
Approximate speed converted to feet/sec at a given distance(33mph at 60'=48.4'sec)
multiply the feet/sec by the time diff(48.4X .115=5.57')
I used 33 mph at 60',63.6mph at 330',81mph at 1/8.For the 1/4 mile times I used my formula previously mentioned but used 1.5mph higher for Grogan as it looks like even my ave speed increases over yours after the 1/8.
O course their are many variables,road,weather reaction times etc.but based on our respective data you are the winner!!
[/quote]Very cool grogan, but you are catching me. On the rear-end ratio thing, I think you have smaller diameter rear tires, but am not sure. I will think about your "virtual" calcs later. I am in a very cold conference room in Bruges. The internet is free in here, but there is no conference so there is no heat. I am going to try to post the graphs again now.

Nope, no luck yet. I'll keep trying, but not tonight. Grrrrr!

 

Very cool grogan, but you are catching me. On the rear-end ratio thing, I think you have smaller diameter rear tires, but am not sure. I will think about your "virtual" calcs later. I am in a very cold conference room in Bruges. The internet is free in here, but there is no conference so there is no heat. I am going to try to post the graphs again now.

Nope, no luck yet. I'll keep trying, but not tonight. Grrrrr!
[/quote]

Hello again Znod,
Catching you slooowly(gained about 7' in the second 1/8).
You are right about the diff in ratio due to tire size.The standard goodyear RSA 225/50 are 25.9" dia.
Guessing you have PS2 that are 245's(19")dia. is 26.7"
I know there are a number of members reading this thread(over 1100 hits).They must think we are severly abusing our cars,but we have been massaging the same data over & over.The truth is I take meticulous care of my car and I am sure you do the same.I have 18000+ miles on it now and I would venture that only about 20 miles were spent at wide open throttle.
I do intend to make a few more runs when the weather gets better to see if I can improve my times.

PS after analizing your info regarding time diff to speed I think some of the anomalies are due to shift points.
1 to 2 shift between 30 & 40 mph causes the time diff to be larger between these speeds.Same also occurs between 60 & 70(shift to 3).This causes the time diff between these speeds to be almost the same as the diff's betwenn 40 & 50 and 70 & 80.

 

Very cool grogan, but you are catching me. On the rear-end ratio thing, I think you have smaller diameter rear tires, but am not sure. I will think about your "virtual" calcs later. I am in a very cold conference room in Bruges. The internet is free in here, but there is no conference so there is no heat. I am going to try to post the graphs again now.

Nope, no luck yet. I'll keep trying, but not tonight. Grrrrr!
[/quote]

Hello again Znod,
Catching you slooowly(gained about 7' in the second 1/8).
You are right about the diff in ratio due to tire size.The standard goodyear RSA 225/50 are 25.9" dia.
Guessing you have PS2 that are 245's(19")dia. is 26.7"
I know there are a number of members reading this thread(over 1100 hits).They must think we are severly abusing our cars,but we have been massaging the same data over & over.The truth is I take meticulous care of my car and I am sure you do the same.I have 18000+ miles on it now and I would venture that only about 20 miles were spent at wide open throttle.
I do intend to make a few more runs when the weather gets better to see if I can improve my times.

PS after analizing your info regarding time diff to speed I think some of the anomalies are due to shift points.
1 to 2 shift between 30 & 40 mph causes the time diff to be larger between these speeds.Same also occurs between 60 & 70(shift to 3).This causes the time diff between these speeds to be almost the same as the diff's betwenn 40 & 50 and 70 & 80.
[/quote]Good point. I had not thought of that. Do you think maybe your car is shifting faster than mine. Also, I thought of something else about your higher terminal speed. On your better runs, you seem to be getting more wheel spin than me--on my better runs. I remember an old drag-racing saw to the effect that a slower ET and a higher MPH is indicative of extra wheel spin. Have you heard this one, and does it make sense to you? Could it explain both my "jump" and your extra mph? Yes, I take great care of my car. I really haven't done that many runs. I think I can improve though and will be doing some more.

We are back in London. I'll be posting a new thread on gains from mods based on your formula tonight; it's 7:36 p.m. right now. Your formula is the key; the rest is easy. Check it out when you get the chance.

 

Very cool grogan, but you are catching me. On the rear-end ratio thing, I think you have smaller diameter rear tires, but am not sure. I will think about your "virtual" calcs later. I am in a very cold conference room in Bruges. The internet is free in here, but there is no conference so there is no heat. I am going to try to post the graphs again now.

Nope, no luck yet. I'll keep trying, but not tonight. Grrrrr!
[/quote]

Hello again Znod,
Catching you slooowly(gained about 7' in the second 1/8).
You are right about the diff in ratio due to tire size.The standard goodyear RSA 225/50 are 25.9" dia.
Guessing you have PS2 that are 245's(19")dia. is 26.7"
I know there are a number of members reading this thread(over 1100 hits).They must think we are severly abusing our cars,but we have been massaging the same data over & over.The truth is I take meticulous care of my car and I am sure you do the same.I have 18000+ miles on it now and I would venture that only about 20 miles were spent at wide open throttle.
I do intend to make a few more runs when the weather gets better to see if I can improve my times.

PS after analizing your info regarding time diff to speed I think some of the anomalies are due to shift points.
1 to 2 shift between 30 & 40 mph causes the time diff to be larger between these speeds.Same also occurs between 60 & 70(shift to 3).This causes the time diff between these speeds to be almost the same as the diff's betwenn 40 & 50 and 70 & 80.
[/quote]Good point. I had not thought of that. Do you think maybe your car is shifting faster than mine. Also, I thought of something else about your higher terminal speed. On your better runs, you seem to be getting more wheel spin than me--on my better runs. I remember an old drag-racing saw to the effect that a slower ET and a higher MPH is indicative of extra wheel spin. Have you heard this one, and does it make sense to you? Could it explain both my "jump" and your extra mph? Yes, I take great care of my car. I really haven't done that many runs. I think I can improve though and will be doing some more.

We are back in London. I'll be posting a new thread on gains from mods based on your formula tonight; it's 7:36 p.m. right now. Your formula is the key; the rest is easy. Check it out when you get the chance.
[/quote]

I am not sure my car is shifting faster than yours,but since you brought up this point I can tell you that I have never been satisfied with the way the steps shift.At full throttle the shifts are relatively slow and soft(too much computer control of torque).I think there is another .1 or .2 sec to be shaved if the shifts were crisper.There seems to be much less computer interference at 1/2 throttle.
On your point of higher terminal speeds with more wheel spin I am not sure.My memory on this point is that terminal speed is relatively unaffected by wheel spin or bog down,but is a function of horsepower.I recall Racers starting in 2nd gear to gain traction,losing several tens in et,but attaining the same terminal speed.
Below post of a run I made in august of this year indicates that you may be correct.The early times to speed and distance are better than previous #s but the 1/8 speed is down a little(82+ to 81.6).
10 .25
20 .95
30 1.67
40 2.82
50 3.85
60 5.05
70 6.60
80 8.23
90 9.95
60' 1.95
330' 5.70 1/8 8.75 & 81.6mph
Even though my start was better(1.95 60')above 50 I showed no improvement over previous times and my speed at 1/8 was slightly lower.This run was in the N(downhill direction).The big variable here is the weather this run was made in mid august(hotter & more humid).The previous runs were made in mid may.

 

Very cool grogan, but you are catching me. On the rear-end ratio thing, I think you have smaller diameter rear tires, but am not sure. I will think about your "virtual" calcs later. I am in a very cold conference room in Bruges. The internet is free in here, but there is no conference so there is no heat. I am going to try to post the graphs again now.

Nope, no luck yet. I'll keep trying, but not tonight. Grrrrr!
[/quote]

Hello again Znod,
Catching you slooowly(gained about 7' in the second 1/8).
You are right about the diff in ratio due to tire size.The standard goodyear RSA 225/50 are 25.9" dia.
Guessing you have PS2 that are 245's(19")dia. is 26.7"
I know there are a number of members reading this thread(over 1100 hits).They must think we are severly abusing our cars,but we have been massaging the same data over & over.The truth is I take meticulous care of my car and I am sure you do the same.I have 18000+ miles on it now and I would venture that only about 20 miles were spent at wide open throttle.
I do intend to make a few more runs when the weather gets better to see if I can improve my times.

PS after analizing your info regarding time diff to speed I think some of the anomalies are due to shift points.
1 to 2 shift between 30 & 40 mph causes the time diff to be larger between these speeds.Same also occurs between 60 & 70(shift to 3).This causes the time diff between these speeds to be almost the same as the diff's betwenn 40 & 50 and 70 & 80.
[/quote]Good point. I had not thought of that. Do you think maybe your car is shifting faster than mine. Also, I thought of something else about your higher terminal speed. On your better runs, you seem to be getting more wheel spin than me--on my better runs. I remember an old drag-racing saw to the effect that a slower ET and a higher MPH is indicative of extra wheel spin. Have you heard this one, and does it make sense to you? Could it explain both my "jump" and your extra mph? Yes, I take great care of my car. I really haven't done that many runs. I think I can improve though and will be doing some more.

We are back in London. I'll be posting a new thread on gains from mods based on your formula tonight; it's 7:36 p.m. right now. Your formula is the key; the rest is easy. Check it out when you get the chance.
[/quote]

I am not sure my car is shifting faster than yours,but since you brought up this point I can tell you that I have never been satisfied with the way the steps shift.At full throttle the shifts are relatively slow and soft(too much computer control of torque).I think there is another .1 or .2 sec to be shaved if the shifts were crisper.There seems to be much less computer interference at 1/2 throttle.

I agree with all of what you say. It's funny about the shifting being crisper at, say, half throttle. Sometimes I have even aborted runs because the shift from 1 to 2 is so poor. These poor shifts are highly correlated with excess wheel spin even though I have both DSC and DTC off. Have you had any 1 to 2 shifts that were so bad you aborted the runs?

On your point of higher terminal speeds with more wheel spin I am not sure.My memory on this point is that terminal speed is relatively unaffected by wheel spin or bog down,but is a function of horsepower.I recall Racers starting in 2nd gear to gain traction,losing several tens in et,but attaining the same terminal speed.
Below post of a run I made in august of this year indicates that you may be correct.The early times to speed and distance are better than previous #s but the 1/8 speed is down a little(82+ to 81.6).
10 .25
20 .95
30 1.67
40 2.82
50 3.85
60 5.05
70 6.60
80 8.23
90 9.95
60' 1.95
330' 5.70 1/8 8.75 & 81.6mph
Even though my start was better(1.95 60')above 50 I showed no improvement over previous times and my speed at 1/8 was slightly lower.This run was in the N(downhill direction).The big variable here is the weather this run was made in mid august(hotter & more humid).The previous runs were made in mid may.

I see what you mean. What you say sort of supports my point, but there is not enough data to draw much in the way of a conclusion. Thanks for thinking about the issue. We are back--and darn tired and sleepy. I can barely keep my eyes open so I am putting the computer down. Later.
[/quote]

 

Very cool grogan, but you are catching me. On the rear-end ratio thing, I think you have smaller diameter rear tires, but am not sure. I will think about your "virtual" calcs later. I am in a very cold conference room in Bruges. The internet is free in here, but there is no conference so there is no heat. I am going to try to post the graphs again now.

Nope, no luck yet. I'll keep trying, but not tonight. Grrrrr!
[/quote]

Hello again Znod,
Catching you slooowly(gained about 7' in the second 1/8).
You are right about the diff in ratio due to tire size.The standard goodyear RSA 225/50 are 25.9" dia.
Guessing you have PS2 that are 245's(19")dia. is 26.7"
I know there are a number of members reading this thread(over 1100 hits).They must think we are severly abusing our cars,but we have been massaging the same data over & over.The truth is I take meticulous care of my car and I am sure you do the same.I have 18000+ miles on it now and I would venture that only about 20 miles were spent at wide open throttle.
I do intend to make a few more runs when the weather gets better to see if I can improve my times.

PS after analizing your info regarding time diff to speed I think some of the anomalies are due to shift points.
1 to 2 shift between 30 & 40 mph causes the time diff to be larger between these speeds.Same also occurs between 60 & 70(shift to 3).This causes the time diff between these speeds to be almost the same as the diff's betwenn 40 & 50 and 70 & 80.
[/quote]Good point. I had not thought of that. Do you think maybe your car is shifting faster than mine. Also, I thought of something else about your higher terminal speed. On your better runs, you seem to be getting more wheel spin than me--on my better runs. I remember an old drag-racing saw to the effect that a slower ET and a higher MPH is indicative of extra wheel spin. Have you heard this one, and does it make sense to you? Could it explain both my "jump" and your extra mph? Yes, I take great care of my car. I really haven't done that many runs. I think I can improve though and will be doing some more.

We are back in London. I'll be posting a new thread on gains from mods based on your formula tonight; it's 7:36 p.m. right now. Your formula is the key; the rest is easy. Check it out when you get the chance.
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I am not sure my car is shifting faster than yours,but since you brought up this point I can tell you that I have never been satisfied with the way the steps shift.At full throttle the shifts are relatively slow and soft(too much computer control of torque).I think there is another .1 or .2 sec to be shaved if the shifts were crisper.There seems to be much less computer interference at 1/2 throttle.

I agree with all of what you say. It's funny about the shifting being crisper at, say, half throttle. Sometimes I have even aborted runs because the shift from 1 to 2 is so poor. These poor shifts are highly correlated with excess wheel spin even though I have both DSC and DTC off. Have you had any 1 to 2 shifts that were so bad you aborted the runs?

On your point of higher terminal speeds with more wheel spin I am not sure.My memory on this point is that terminal speed is relatively unaffected by wheel spin or bog down,but is a function of horsepower.I recall Racers starting in 2nd gear to gain traction,losing several tens in et,but attaining the same terminal speed.
Below post of a run I made in august of this year indicates that you may be correct.The early times to speed and distance are better than previous #s but the 1/8 speed is down a little(82+ to 81.6).
10 .25
20 .95
30 1.67
40 2.82
50 3.85
60 5.05
70 6.60
80 8.23
90 9.95
60' 1.95
330' 5.70 1/8 8.75 & 81.6mph
Even though my start was better(1.95 60')above 50 I showed no improvement over previous times and my speed at 1/8 was slightly lower.This run was in the N(downhill direction).The big variable here is the weather this run was made in mid august(hotter & more humid).The previous runs were made in mid may.

I see what you mean. What you say sort of supports my point, but there is not enough data to draw much in the way of a conclusion. Thanks for thinking about the issue. We are back--and darn tired and sleepy. I can barely keep my eyes open so I am putting the computer down. Later.
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Welcome back Znod,hopefully the jet lag is not too severe.

I never aborted a run due to the lazy shifts,but I have aborted runs due to wheel spin.I will continue my efforts for better times until I have recorded the impossible(for a 545)less than 5 sec run to 60mph.I have read in various E60 threads that the times we are recording for 545 steps are not possible,but I trust in you & GT2.

Where do you mount the GT2 for your runs?I mount mine directly in front of the speedometer & tach with the bottom resting on the ledge so as to prevent vibration during a run.I think this points it directly ahead per the GT2 instructions.