***Texas Mile Update!!***
It was never suggested that someone take a casual pleasure cruise through the first half mile, using cruise control with the windows down and waving at the crowd. Some of you simply take things completely out of context.
Every foot matters in terms of length. Period.
Covering the first 60 feet with a wheelstanding launch has very little to do with the final trap speed at the end of a mile. Rolling into the throttle and accelerating as quickly as your traction will allow will result in similar results at the end of the mile. Just like spinning at the drag strip off the line rarely changes your mph at the end of a 1/4-mile. If anything, that spin off the line improves your trap speed. Isn't that the goal here?
Tony is right, an easy launch doesn't really hurt the final mph. At 150 mph the camaro was probably accelerating at around 18 mph per second. At 250 mph the car is only accelerating at around .75 mph per second. An easy launch helps to save parts.
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From: HOUSTON
Someone didn't read the thread.
It was never suggested that someone take a casual pleasure cruise through the first half mile, using cruise control with the windows down and waving at the crowd. Some of you simply take things completely out of context.
Every foot matters in terms of length. Period.
Covering the first 60 feet with a wheelstanding launch has very little to do with the final trap speed at the end of a mile. Rolling into the throttle and accelerating as quickly as your traction will allow will result in similar results at the end of the mile. Just like spinning at the drag strip off the line rarely changes your mph at the end of a 1/4-mile. If anything, that spin off the line improves your trap speed. Isn't that the goal here?
It was never suggested that someone take a casual pleasure cruise through the first half mile, using cruise control with the windows down and waving at the crowd. Some of you simply take things completely out of context.
Every foot matters in terms of length. Period.
Covering the first 60 feet with a wheelstanding launch has very little to do with the final trap speed at the end of a mile. Rolling into the throttle and accelerating as quickly as your traction will allow will result in similar results at the end of the mile. Just like spinning at the drag strip off the line rarely changes your mph at the end of a 1/4-mile. If anything, that spin off the line improves your trap speed. Isn't that the goal here?
My point was I still think improvement can be had beyond adding more power on the big end, but maybe they are at the limits of what they can achieve in the first few gears. They are only looking for a couple mph. It would be cool to compare vbox runs between this car and the lambo on the 251 pass (Mph vs distance traveled).
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From: HOU - yeah, you know the rest.
Properly setup traction control/boost by gear is the ultimate. If you watch the FGT video you can see how easy they leave the line, and use TC/boost by gear to put it all down and run a number. Lmrs car is boost by gear and no TC. Much more man vs machine approach. Initial launch is definately not the major variable in the final trapspeed.
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From: HOU - yeah, you know the rest.
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From: Houston / University of Texas, Austin
i was the one that posted that originally, but i was just clarifying/reiterating that those top fuel motors are built to run at the edge of blowing up for a 1/4 mile. :o 
Regarding trap speed and "every foot counts", a car at the end of the mile is both accelerating SLOWLY and covering LARGE DISTANCES over short time periods. Here's a different look at some (approximate) numbers. . . .
At 253mph, a car is covering 371 feet per second.
Assume at the 1-mile marker, a car is still accelerating at 0.1g = 3.2ft/s^2 = 2mph/s
So to gain 2 more mph, the car must accelerate for 1 more second and cover an additional 371+ feet of distance. Likewise, to loose 2mph, the track may be shortened a little less than 371 feet.
Looking at it another way, the first 371 feet of track only have ~2mph influence on the final trap speed, assuming a final acceleration rate of 0.1g at 253mph.
Yet another way, each foot is worth the following at 253.mph:
0.1g: 1ft = 2mph/371ft = 0.005mph
0.2g: 1ft = 0.01mph
0.3g: 1ft = 0.015mph
The harder a car is accelerating as it passes through the traps, the more important each foot of track becomes. These are just numbers for demonstration purposes, but they are easily scaled to actual numbers, which were surely logged by the lmr crew.
At 253mph, a car is covering 371 feet per second.
Assume at the 1-mile marker, a car is still accelerating at 0.1g = 3.2ft/s^2 = 2mph/s
So to gain 2 more mph, the car must accelerate for 1 more second and cover an additional 371+ feet of distance. Likewise, to loose 2mph, the track may be shortened a little less than 371 feet.
Looking at it another way, the first 371 feet of track only have ~2mph influence on the final trap speed, assuming a final acceleration rate of 0.1g at 253mph.
Yet another way, each foot is worth the following at 253.mph:
0.1g: 1ft = 2mph/371ft = 0.005mph
0.2g: 1ft = 0.01mph
0.3g: 1ft = 0.015mph
The harder a car is accelerating as it passes through the traps, the more important each foot of track becomes. These are just numbers for demonstration purposes, but they are easily scaled to actual numbers, which were surely logged by the lmr crew.
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Roll out 371 feet, stop then hit it hard to the mile I guarantee you will be going more than 2mph faster if you hit it hard from the start line.
The statement is correct. Obviously your car might be accelerating harder than 0.1g through the traps, and might be well under 253mph, then yes, 371ft will make a bigger difference. I don't know how hard your particular car is accelerating through the traps, I just provided some framework for you so you can play with the numbers for yourself.
371ft rollout with 0.2g would coorespond to a ~4mph difference at 253 mph for instance, or 2mph with 185ft rollout.
371ft rollout with 0.2g at 226mph would be (256/226)*4=4.5mph and so on.
All those numbers scale linearly as demonstrated, so the math should be pretty easy to work with if you know your actual speed and accel rate through the traps. . .
371ft rollout with 0.2g would coorespond to a ~4mph difference at 253 mph for instance, or 2mph with 185ft rollout.
371ft rollout with 0.2g at 226mph would be (256/226)*4=4.5mph and so on.
All those numbers scale linearly as demonstrated, so the math should be pretty easy to work with if you know your actual speed and accel rate through the traps. . .
Last edited by drz; Apr 2, 2012 at 09:30 PM.
Mullet, don't you log your runs with the Vbox? What total mph increase are you seeing in the very last second of the run?
Your 226 mph is equal to 331.46 feet/second.
If you can find how many mph you gained in the final second, that would be the approximate difference in finishing mph if the track were 331 feet shorter.
It would be interesting to see the actual data on a fast pass like that.
Your 226 mph is equal to 331.46 feet/second.
If you can find how many mph you gained in the final second, that would be the approximate difference in finishing mph if the track were 331 feet shorter.
It would be interesting to see the actual data on a fast pass like that.
Teching In
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Mullet, don't you log your runs with the Vbox? What total mph increase are you seeing in the very last second of the run?
Your 226 mph is equal to 331.46 feet/second.
If you can find how many mph you gained in the final second, that would be the approximate difference in finishing mph if the track were 331 feet shorter.
It would be interesting to see the actual data on a fast pass like that.
Your 226 mph is equal to 331.46 feet/second.
If you can find how many mph you gained in the final second, that would be the approximate difference in finishing mph if the track were 331 feet shorter.
It would be interesting to see the actual data on a fast pass like that.
218.42mph at 5050 feet
221.74mph at 5392 feet
in the first 330 feet I'm doing right around 87mph per my Vbox.
I still stand by this statement of mine
go!