check this out. A Mclaren 12C ran at PBIR with a PBOX on.
Have a look at elevation…looks like 20 feet drop from this car’s 60-130 run. It trapped 134. So that means it had more elevation drop not captured on the graph from 0-60 mph and from 130-135 or so.
That means around a 30-35 foot drop in elevation. That’s HUGE! That’s 2.5%!
http://www.dragtimes.com/images_vbox/25287-2012-Mclaren-MP4-12C-vbox-60-130.jpg
Damn, that’s whack and makes pbir runs much less impressive now. Most of our tracks are slightly uphill. Infineon goes up like pbir goes down.
I’ve been keeping an eye on PBIR for a long time, hoping for a PBOX to get posted. The times there have always been ‘too good to be true’ almost. Guess this explains part of it.
Everything always says 150 but my gps read 185 there, reason I laughed is our old house was down the hill from it and would be underwater if the track was at 10.
All these records going down there, hell I can push a car twice as fast down hill, I should use some of our grades and go set a bunch of 60-130 records.
In for numbers…
Pacific is def uphill, one of my videos on youtube with me bracket racing against an older white z car I almost roll backwards out of the beams while waiting. I used to put my e-brake up one click and launch with it like that and put it down after shifting to second. It was cool cause it also disabled the edl through first and didn’t really hinder me at all.
PBIR is flat:
http://audirevolution.net/forum/index.php?topic=1613.msg40911#msg40911
Sak, can you split the Track Slope (last half) out of the McLaren thread…? I’m hoping to have more to add to the McLaren thread, but the Track Slope talk is a pretty good discussion/reference on it’s own. You can add pbox elevations to that perhaps, we can figure out what’s going on with the differences between the google maps API vs pbox.
yeah I just can’t see a certified track having that large of a drop in elevation…to be honest I doubt PBIR sits anymore than 15 feet above sea level. Almost everything from st. Lucie/ Indian river county and south is around 10 feet above sea level at its highest
All around I95 is flat as Kate Hudson. You’re right PBIR is at 23’ elevation, which explains a lot in itself. Killer DA all the time, just like e-town, ATCO, the LI test track.
I don’t get how Thompson is so fast for you and Prime still, except it, cleverly, faces west. The winds are usually westerly…lol let’s start another theory about Thompson…
heck even the gainesville track is flat and that’s touching north florida, maybe 75 feet above sea level. The only way to see any substantial difference of times in Florida is temperature. Anything above 65 degrees and my car feels like it’s running at least a second slower in the quarter, especially if its humid (which it always is). I have yet to see any time from either g-ville or PBIR that seem consistently faster than they should be
Killer DA??? or killer A
When that McLaren ran 10.6 it was 500+ feet of density altitude. That’s nice, but certainly not killer.
When we went to Cayuga in November and everyone was setting MPH records, the density altitude was -800 to -1100 feet.
http://www.dragtimes.com/da-density-altitude-calculator.php?temperature=35.6&rh=65&altset=30.15&elevation=630&track=190&month=11&day=4&year=2012&time=12:00 PM
On the weekend when AMD went to the dragstrip in Seattle at 40 fahrenheit, the density altitude was -1500 feet. That’s killer to me. You may have a different definition.
That’s all according to dragtimes.
it’s usually 1000-2500 feet of density altitude there at PBIR. They run overnight sometimes the help. Check the da on that McClaren pass.
Also imolas4 is a 4.2 s4 owner from Florida.
Imolamonster…hahaha that’s who I thought. Oops.
I’ve seen Kate a few times in Rosseau up north, she has no killer A or killer Ds. Flat like PBIR, and honestly she wasn’t someone you’d notice on the street. The nanny she had was frickin hot though.
With those low level tracks, density is always high, so chances of having a decent DA with a nice high temperature is more. For those with traction issues, like that McLaren, having a DA of 500 with a decent temperature is as awesome as it will get.
Also at some point denser air will hurt traps more than it helps the engine…density differences of 7% is easily possible between the tracks we typically talk about, and the air drag on the car really picks up at higher speeds.
Hey can you move from the McLaren thread though, from where I notice the drop in the McLaren pbox? Then maybe you can help correlate the pbox data to the elevations.
I did look at Pacific, it is slightly uphill, the staging area is a bit of a “hump”.
I just posted this information on 6speedonline, home of the 60-130 database everyone follows.
Am I about to be pelted with tomatoes?
+++++++++++++++++++++
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