I just posted this information on 6speedonline, home of the 60-130 database everyone follows.
Am I about to be pelted with tomatoes?
http://www.6speedonline.com/forums/996-turbo-gt2/259006-6speedonlines-official-1-4-mile-60-130-100-150-standing-mile-thread-18.html#post3810499
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I have been looking through the pbox data of a few cars, and found some really interesting information.
The 6speedonline thread allows as much as a -3% negative slope, right? That’s pretty significant. On a really quick car about -20 feet over the 60-130 run. On a slow car like my stock 2008 Audi RS4 (13.5 seconds on a flat road) that’s an elevation drop of up to 50 feet (takes me upwards of 2000 feet to complete the run). Fine.
HOWEVER
Recently a McLaren Mp412C ran at Palm Beach International Raceway on the dragstrip, and had his pbox running. He ran an incredible 10.37 quarter mile time bone stock. Nuts. Anyway, his pbox on one of his runs showed a negative slope over his 60-130 (6.6 seconds for interest’s sake). The negative slope showed as -2.5% or about 25 feet. over the entire dragstrip 1320 foot run, the drop was about 30 feet.
Wait a second…the dragstrip at PBIR has a -30 foot elevation change from start to finish?
Not according to PBIR
Not according to google earth
Not according to the NHRA
Not according to surveys of the land
Not according to anything I could see that measured elevation change over that stretch of land.
Just the pbox.
So the pbox, we can assume, was off. It got the elevation change wrong by almost 3%. Or everyone else made a mistake (unlikely). Or PBIR is cheating in order to hold a reputaiton as a fast track (possible in theory, but reputation risk and NHRA certification make this just about impossible)
Does this concern anyone? I’ve also seen this on my own pbox. -8 foot drop on one dragstrip pass…and a positive 3 foot slope on the next pass. -17 feet at Thompson raceway in Ohio on one pass, less on another, and flat on all the survey and geo data I have seen, not to mention IHRA certification.
Here’s the 60-130 graph, and then a video of the quarter mile run.
http://www.dragtimes.com/images_vbox/25329-2012-Mclaren-MP4-12C-vbox-60-130.jpg
http://www.youtube.com/watch?v=cPJ9ItB7zPI