znod

Hi Grogan:

I have been wondering about much of what you said. I have done some Excel graphs to focus more clearlhy on the issues. I can't provide detail now, but will do so at least when we return to the US. I will think about your formula and get back to you. Also, I had two 8.71's for the 1/8. As I recall, those are a little better than your best--8.75 maybe (check above please). In brief, what looks strange to me is that I am faster to 40 (or was it 50; you are faster to 60 (and 70 or 80); but I am faster in the 1/8 although your terminal velocity is higher. It looks to me like your 50 - 70 times are out of line with the rest of our data, but take this conclusion with a grain of salt because I have not finished with my graphing, etc. Happy New Year!!
[/quote]

Happy new year to you also znod.Hope you are vacationing and having a good time.I have some theories on our respective times.We will discuss at length when you get back.You are correct about your best 1/8 times being better than mine.I was speaking of speed at the end of the 1/8
[/quote]HNY grogan. Be safe tonight. I have some new discussion below. Happy thinking about what is going on.

I have read your post on weight reduction and agree with all your info and calculations.We always used the .1 and 1mph per 10hp rule when making changes.We also used .1 and 1mph per 100# weight reduction.

There is no substitute for the knowledge of the ancients.

I am wondering why our GT2 times are so similar since you have made some mods & reduced weight. Possibly because I have more than 15000 miles and also the ambient temps were much higher for your tests.I did notice your 60' & 1/8 times are on average slightly faster but 1/8 speed is slightly slower than mine.

Even though I have made a case for my mods making a difference, it is possible that the only difference I have made is some weight reduction. Also, it is possible that your car is exceptional or that its additional mileage makes a significant difference. Originally, I raised the issue of whether your car got faster over time. You mentioned at least that you did not document the difference, etc. I do think/know that many cars get measurably and, perhaps, even noticeably faster by 15k or more miles.

And, earlier, after you mentioned using brake torquing, I assumed that your car was faster to 60 because of the use of this procedure. But, then, I noticed that I was faster up to 40 on average and that our cars were essentially the same up to 50 on average. But, then your car seemed to explode from 40 to 80 on average only to lose on average in the 1/8 while having a higher terminal velocity on average. Given these observations, I started looking at our data more closely.

I have plotted a variety of curves for our cars, on average, and also have plotted curves of the auto-mag data on average. My plots seem to imply that there is a possibly extraordinarily linear relationship between MPH and average time from about 40 to 80 for your car. I think that, in concept, such a plot should show time on average to be more of an increasing function of speed from 40 to 80. This relationship is apparent in plots for my car from 0 to 80 and for the auto-mag averages from 30 to 80. You may be able to see what I am getting at using the data in the two tables below. But, note that your data may be perfectly acceptable and that your car may be exceptional. Indeed, my meter may be lying, and your car actually may be quicker through the 1/8,

Having tossed out my test 2 since it results were somewhat outlier-ish, etc., the headings for the first table are:

Datum/Znod Test 1/Znod Test 2/Znod Test 3/Average/Change (except for the first datum)

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

The above data show that, for my car, time, on average, is an increasing function of speed all the way from 10 to 80 (except for 40 to 50)?which mirrors the expected pattern with one exception.

Below is a similar table for your car/data; its headings are:

Datum/grogan Test 1/grogan Test 2/grogan Test 3/Average/Change (except for the first daum)

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 1.59
0-60 5.03 5.00 5.05 5.03 1.18
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

The data in this table bear out the not perfectly, but pretty much, linear relationship for time, on average, as a function of speed for your car from 40 to 80. Something about these data does not look quite right?i.e., especially the two 1.59 and the two 1.04 values. Also, the data say that it took you .59 sec. to go from 80 to 81.77 on average. What do you think about the change in time on average values for our cars? And, remember the auto-mag patterns look like mine. I still need to add one mag to the mag results. I managed to get to London without all my data.

If you happen to have Road and Track 6/05, then would you mind posting all the acceleration-related data for the 545i. If so, then I can provide you with the complete mag results. Thanks.

I have not had time to think about the formula yet. But, I will get to it soon?before we return to the US. I will find a way to post my plots after we return.

grogan545

Hi Grogan:

I have been wondering about much of what you said. I have done some Excel graphs to focus more clearlhy on the issues. I can't provide detail now, but will do so at least when we return to the US. I will think about your formula and get back to you. Also, I had two 8.71's for the 1/8. As I recall, those are a little better than your best--8.75 maybe (check above please). In brief, what looks strange to me is that I am faster to 40 (or was it 50; you are faster to 60 (and 70 or 80); but I am faster in the 1/8 although your terminal velocity is higher. It looks to me like your 50 - 70 times are out of line with the rest of our data, but take this conclusion with a grain of salt because I have not finished with my graphing, etc. Happy New Year!!
[/quote]

Happy new year to you also znod.Hope you are vacationing and having a good time.I have some theories on our respective times.We will discuss at length when you get back.You are correct about your best 1/8 times being better than mine.I was speaking of speed at the end of the 1/8
[/quote]HNY grogan. Be safe tonight. I have some new discussion below. Happy thinking about what is going on.

I have read your post on weight reduction and agree with all your info and calculations.We always used the .1 and 1mph per 10hp rule when making changes.We also used .1 and 1mph per 100# weight reduction.

There is no substitute for the knowledge of the ancients.

I am wondering why our GT2 times are so similar since you have made some mods & reduced weight. Possibly because I have more than 15000 miles and also the ambient temps were much higher for your tests.I did notice your 60' & 1/8 times are on average slightly faster but 1/8 speed is slightly slower than mine.

Even though I have made a case for my mods making a difference, it is possible that the only difference I have made is some weight reduction. Also, it is possible that your car is exceptional or that its additional mileage makes a significant difference. Originally, I raised the issue of whether your car got faster over time. You mentioned at least that you did not document the difference, etc. I do think/know that many cars get measurably and, perhaps, even noticeably faster by 15k or more miles.

And, earlier, after you mentioned using brake torquing, I assumed that your car was faster to 60 because of the use of this procedure. But, then, I noticed that I was faster up to 40 on average and that our cars were essentially the same up to 50 on average. But, then your car seemed to explode from 40 to 80 on average only to lose on average in the 1/8 while having a higher terminal velocity on average. Given these observations, I started looking at our data more closely.

I have plotted a variety of curves for our cars, on average, and also have plotted curves of the auto-mag data on average. My plots seem to imply that there is a possibly extraordinarily linear relationship between MPH and average time from about 40 to 80 for your car. I think that, in concept, such a plot should show time on average to be more of an increasing function of speed from 40 to 80. This relationship is apparent in plots for my car from 0 to 80 and for the auto-mag averages from 30 to 80. You may be able to see what I am getting at using the data in the two tables below. But, note that your data may be perfectly acceptable and that your car may be exceptional. Indeed, my meter may be lying, and your car actually may be quicker through the 1/8,

Having tossed out my test 2 since it results were somewhat outlier-ish, etc., the headings for the first table are:

Datum/Znod Test 1/Znod Test 2/Znod Test 3/Average/Change (except for the first datum)

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

The above data show that, for my car, time, on average, is an increasing function of speed all the way from 10 to 80 (except for 40 to 50)?which mirrors the expected pattern with one exception.

Below is a similar table for your car/data; its headings are:

Datum/grogan Test 1/grogan Test 2/grogan Test 3/Average/Change (except for the first daum)

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 1.59
0-60 5.03 5.00 5.05 5.03 1.18
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

The data in this table bear out the not perfectly, but pretty much, linear relationship for time, on average, as a function of speed for your car from 40 to 80. Something about these data does not look quite right?i.e., especially the two 1.59 and the two 1.04 values. Also, the data say that it took you .59 sec. to go from 80 to 81.77 on average. What do you think about the change in time on average values for our cars? And, remember the auto-mag patterns look like mine. I still need to add one mag to the mag results. I managed to get to London without all my data.

If you happen to have Road and Track 6/05, then would you mind posting all the acceleration-related data for the 545i. If so, then I can provide you with the complete mag results. Thanks.

I have not had time to think about the formula yet. But, I will get to it soon?before we return to the US. I will find a way to post my plots after we return.
[/quote]

Hi again Znod.I do have the magazine your looking for at work.I answered your post in the E60 forum.Very interesting data.Did you take into account that my runs are in opposit directions?Although I can't see it, the road I test on must have a slight grade.It is obvious by my times that something is different.Do you test in opposite directions on the same road?I believe the decrease in "time to speed"in my "northbound"runs are slightly down hill.IMO on a down hill road at the faster speeds(60+),the time to speed will decrease when compared to a perfectly level road.The diff in acceleration is greater as you increase speed on a down hill run.It does't make as much diff at lower speeds because of torque multiplication of lower gears and lower wind resistance. Your times are so consistant that it appears that they are all in the same direction or that your test road is perfectly level.What do you think Znod?

znod

Hi Grogan:

I have been wondering about much of what you said. I have done some Excel graphs to focus more clearlhy on the issues. I can't provide detail now, but will do so at least when we return to the US. I will think about your formula and get back to you. Also, I had two 8.71's for the 1/8. As I recall, those are a little better than your best--8.75 maybe (check above please). In brief, what looks strange to me is that I am faster to 40 (or was it 50; you are faster to 60 (and 70 or 80); but I am faster in the 1/8 although your terminal velocity is higher. It looks to me like your 50 - 70 times are out of line with the rest of our data, but take this conclusion with a grain of salt because I have not finished with my graphing, etc. Happy New Year!!
[/quote]

Happy new year to you also znod.Hope you are vacationing and having a good time.I have some theories on our respective times.We will discuss at length when you get back.You are correct about your best 1/8 times being better than mine.I was speaking of speed at the end of the 1/8
[/quote]HNY grogan. Be safe tonight. I have some new discussion below. Happy thinking about what is going on.

I have read your post on weight reduction and agree with all your info and calculations.We always used the .1 and 1mph per 10hp rule when making changes.We also used .1 and 1mph per 100# weight reduction.

There is no substitute for the knowledge of the ancients.

I am wondering why our GT2 times are so similar since you have made some mods & reduced weight. Possibly because I have more than 15000 miles and also the ambient temps were much higher for your tests.I did notice your 60' & 1/8 times are on average slightly faster but 1/8 speed is slightly slower than mine.

Even though I have made a case for my mods making a difference, it is possible that the only difference I have made is some weight reduction. Also, it is possible that your car is exceptional or that its additional mileage makes a significant difference. Originally, I raised the issue of whether your car got faster over time. You mentioned at least that you did not document the difference, etc. I do think/know that many cars get measurably and, perhaps, even noticeably faster by 15k or more miles.

And, earlier, after you mentioned using brake torquing, I assumed that your car was faster to 60 because of the use of this procedure. But, then, I noticed that I was faster up to 40 on average and that our cars were essentially the same up to 50 on average. But, then your car seemed to explode from 40 to 80 on average only to lose on average in the 1/8 while having a higher terminal velocity on average. Given these observations, I started looking at our data more closely.

I have plotted a variety of curves for our cars, on average, and also have plotted curves of the auto-mag data on average. My plots seem to imply that there is a possibly extraordinarily linear relationship between MPH and average time from about 40 to 80 for your car. I think that, in concept, such a plot should show time on average to be more of an increasing function of speed from 40 to 80. This relationship is apparent in plots for my car from 0 to 80 and for the auto-mag averages from 30 to 80. You may be able to see what I am getting at using the data in the two tables below. But, note that your data may be perfectly acceptable and that your car may be exceptional. Indeed, my meter may be lying, and your car actually may be quicker through the 1/8,

Having tossed out my test 2 since it results were somewhat outlier-ish, etc., the headings for the first table are:

Datum/Znod Test 1/Znod Test 2/Znod Test 3/Average/Change (except for the first datum)

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

The above data show that, for my car, time, on average, is an increasing function of speed all the way from 10 to 80 (except for 40 to 50)?which mirrors the expected pattern with one exception.

Below is a similar table for your car/data; its headings are:

Datum/grogan Test 1/grogan Test 2/grogan Test 3/Average/Change (except for the first daum)

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 1.59
0-60 5.03 5.00 5.05 5.03 1.18
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

The data in this table bear out the not perfectly, but pretty much, linear relationship for time, on average, as a function of speed for your car from 40 to 80. Something about these data does not look quite right?i.e., especially the two 1.59 and the two 1.04 values. Also, the data say that it took you .59 sec. to go from 80 to 81.77 on average. What do you think about the change in time on average values for our cars? And, remember the auto-mag patterns look like mine. I still need to add one mag to the mag results. I managed to get to London without all my data.

If you happen to have Road and Track 6/05, then would you mind posting all the acceleration-related data for the 545i. If so, then I can provide you with the complete mag results. Thanks.

I have not had time to think about the formula yet. But, I will get to it soon?before we return to the US. I will find a way to post my plots after we return.
[/quote]

Hi again Znod.I do have the magazine your looking for at work.I answered your post in the E60 forum.Very interesting data.Did you take into account that my runs are in opposit directions?Although I can't see it, the road I test on must have a slight grade.It is obvious by my times that something is different.Do you test in opposite directions on the same road?I believe the decrease in "time to speed"in my "northbound"runs are slightly down hill.IMO on a down hill road at the faster speeds(60+),the time to speed will decrease when compared to a perfectly level road.The diff in acceleration is greater as you increase speed on a down hill run.It does't make as much diff at lower speeds because of torque multiplication of lower gears and lower wind resistance. Your times are so consistant that it appears that they are all in the same direction or that your test road is perfectly level.What do you think Znod?
[/quote]I don't have much time right this minute. I used only your 10" roll out data--your three fastest sets of data. Two runs were in one direction (N) and one was in the other (S). Looking back, all your runs are pretty similar to 60, but, yes, the south run is much slolwer from 60 on. I think I'll include your south run twice when I get a chance and see how thing look. It could be the you are a little downhill to the north and opposite for the south. My runs all were in one direction, but I am confident in my "track" flatness. Still, one day, I'll try some the other direction.

znod

I don't have much time right this minute. I used only your 10" roll out data--your three fastest sets of data. Two runs were in one direction (N) and one was in the other (S). Looking back, all your runs are pretty similar to 60, but, yes, the south run is much slolwer from 60 on. I think I'll include your south run twice when I get a chance and see how thing look. It could be the you are a little downhill to the north and opposite for the south. My runs all were in one direction, but I am confident in my "track" flatness. Still, one day, I'll try some the other direction.
[/quote]I added in your south run data again. The pattern looked more "normal," but still about the same. Here are the new data.

Datum/grogan Test1/grogan Test2/grogan Test3/grogan Test 3 (again)/Average/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
0-100
0-90
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 1.63
0-60 5.03 5.00 5.05 5.05 5.03 1.18
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

Below are the data from one test of a C6 Z51 Corvette. Your patten(s) of changes falls in between my pattern and the pattern for the C6.

Datum/Value/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

Have fun with the data. We are at the Eurostar station waiting for the 200 mph train to Bussels. Chec what's below.

We are there now. Isn't technology (sort of) cool. I still like the 50's.

znod

I have read your post on weight reduction and agree with all your info and calculations.We always used the .1 and 1mph per 10hp rule when making changes.We also used .1 and 1mph per 100# weight reduction.

I am wondering why our GT2 times are so similar since you have made some mods & reduced weight.Possibly because I have more than 15000 miles and also the ambient temps were much higher for your tests.I did notice your 60' & 1/8 times are on average slightly faster but 1/8 speed is slightly slower than mine.
I see that you are big on theoretical calculations,so am I.I have developed a formula to predict 1/4 Mile ET from the GT2 1/8 mile times.You have to assume a speed at the end of the 1/4 mile but this isn't difficult since it has been published in many magazines(102 to 104).Below is an example.
1/8 time-8.75
1/8 speed 82.0
assume 1/4 speed of 103-82.0=21mph diff
assume the 60% of the diff will be the average speed over the last 1/8,.6x21=12.6
add 12.6 to 82.0=94.6mph average over the last 1/8
94.6mph=138.75 feet/sec
time to travel the last 1/8=660'/138.75=4.757 sec
add 4.757 to 8.75=13.507 ET for the 1/4 mile.
I know this is a lot of assuming but I used this formula on the 1 drag strip run I made and it was only .01 sec diff from actual(14.09 vs 14.10)
Varying the theoretical mph only changes the ET by .04sec per 1mph
Using this formula on your best posted run gives you a 13.497 ET.What do you think?
[/quote]

Hi gorgan. I think the formula is very good--really like it. Way to go. I have not finishing thinking about it, but the key assumption appears to be the 60%. I am going to think more about this value and how sensitive the results of the formula are to the percent assumed. Below are some calculations that I made for my car. In the second two, I assume that my speed at the end of 1/8 was 82--like yours. As you indicate, the formula is not very sensitive to the assumed terminal mph. You'll understand what I did.

We are off to explore Brussels now. The Metropole Hotel is incredible; got a free room upgrade. Brussels looks terrific so far. Enjoy the calculations. And, I have the missing car-mag data now. Thanks though. I will post the revised data for the car mags later. Not much changed; the pattern stayed essentially the same.

103 mph assumed
8.71
80.50
22.50
13.50
94.00
4.7870
13.50

103 mph assumed
8.71
82.00
21.00
12.60
94.60
4.7568
13.47

104 mph assumed
8.71
80.50
23.50
14.10
94.60
4.7568
13.47

104 mph assumed
8.71
82.00
22.00
13.20
95.20
4.7268
13.44

105 mph assumed
8.71
80.50
24.50
14.70
95.20
4.7268
13.44

105 mph assumed
8.71
82.00
23.00
13.80
95.80
4.6970
13.41

All but one calcualation puts me in the 13.40's. I'd be pretty happy with 13.45, or there abouts, given that the mags got 13.7/13.8 (with an outlier for the manual of 14.1). Also, one mag got 13.7 for a 645i.

znod

Hi grogan and all:

Here are the data for the mags. Note that the changes are generally are larger than, but similar to, mine--i.e., time on average is an increasing function of speed. Note that the "goofy" 8.40 to 80 time for RT produces the anamolous change of 1.62. Go figure.

Headings: MT/RT/MT/Average/Change

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 x.xx 1.10 1.10 1.10
0-10
0-0 x.xx 0.00

Once I get back to the US and link to the graphs of all these changes, then all that I am getting at will be clearer, but I am sure your have the idea. Reiterating, your formula is very cool.

I can't imagine others not being interested enough to join in. But, anyway, new quiz. Name this racer.

grogan545

Hi grogan and all:

Here are the data for the mags. Note that the changes are generally are larger than, but similar to, mine--i.e., time on average is an increasing function of speed. Note that the "goofy" 8.40 to 80 time for RT produces the anamolous change of 1.62. Go figure.

Headings: MT/RT/MT/Average/Change

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 x.xx 1.10 1.10 1.10
0-10
0-0 x.xx 0.00

Once I get back to the US and link to the graphs of all these changes, then all that I am getting at will be clearer, but I am sure your have the idea. Reiterating, your formula is very cool.

I can't imagine others not being interested enough to join in. But, anyway, new quiz. Name this racer.
[/quote]

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.

znod

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.

That would be rewarding even though my mods add benefits beyond performance.

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.

[i]This correction would not make much difference, but it might imply that you are slightly uphill to the south.{/i]

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").

[i]Right, these things definitely could matter. Why do you have only 225's?

2-Your 330 times also faster on average due to lead you got at 60'.

Right.

3-Ditto for 1/8 mile

Right, although you seem to be gaining at the end.

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]I am going to try some opposite direction runs. What you say very well could explain everything.[i]

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"

I am not surprised that we could beat the testers especially if our cars actually are faster.

Seems to be a lot of readers to our conversations but no joiners.
Oh and that racer would be Eddie Hill.

Right again. I forgot that I had that photo--and where I got it.

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.

I knew that I would be online provided that I had decent web access. I do my calculations, etc., when in the evenings and, for example, on the train while my wife reads. We definitely will have a safe trip home. Best to you.

[/quote]

znod

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."

znod

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.