track times, need altitude correction :)

Hey everyone, my first time to the track w/ my new 12 bolt was not a good day, but not a bad one.
before I tell you my times I am at 3200-3300ft (we will say 3300 :) )
dont know the humidity, but it was raining 2-3 miles away. temp was about 70deg.
best run of the day:
60': 2.176
1/8: 8.963
mph:80.69
1/4:13.767
mph:103.28

****ty times for my mods, but the 60' tells it all I know.
Drag radials may not be enough for a 12 bolt... that or I can't launch (already knew that one)

anyone know how to figure out the DA?
thanks

http://wahiduddin.net/calc/calc_da.htm

Check a weather website for the numbers you need.

Also, http://wahiduddin.net/calc/calc_hp_abs.htm
To figure out how much that hurt you...gives you SAE corrected numbers.

I ran a 13.9 at 104 on a 2.4 60' with that cam and home ported heads and street tires at 3500 ft. So your not doing to bad.

I calculated out the DA and it was 4985 :0
that seems huge, but with this how do I calculate out my times?
thanks for the help..

http://www.stangbangerz.com/modules.php?op=modload&name=hpmph&file=density

damn so corrected I ran a 12.9@109.9
seems a little high to me, but I guess that is @ perfect temp, humidity, and 0 altitude... 109.9 is high for my mods. I am finally happy :0

Ya i know made me happy too but i still wont miss that 230/236 cam at all. I hope i like my new setup better...if it ever gets done.

96LT1TX, I remember your post when you took your car to the track and blew up your stock rear :) I see you have the 12 bolt in there now, but are still having problems with traction. If you got that 60' time down you will be in the deep 12's for sure trapping 110 mph. And getting a good 60' will only be a matter of time & practice now that you have the good clutch and moser rear.

Welcome to high altitude racing. When the DA goes below 5000 feet here, I call it a good day to race. My car's waiting for a new engine so I've been racing my daily driver truck for the last few races. Today I was running 15.0's and occasionally dipping into a 14.9x. Corrected for density altitude I would have run 14.40 at sea level. I lost .6 just because of the high altitude. That's also the equivalent of me losing 34 hp. Power to weight calculations say I'm only producing 270 hp but corrected to altitude I make 304 hp. That's trying to move a 4600 pound truck.

To properly convert DA you need to know the elevation of the track, temperature, barometric pressure (corrected/sea level pressure) and humidity. The humidity isn't a big factor in DA but humidity is what determines vapour pressure. A high vapour pressure and you lose hp.

Welcome to high altitude racing. When the DA goes below 5000 feet here, I call it a good day to race. My car's waiting for a new engine so I've been racing my daily driver truck for the last few races. Today I was running 15.0's and occasionally dipping into a 14.9x. Corrected for density altitude I would have run 14.40 at sea level. I lost .6 just because of the high altitude. That's also the equivalent of me losing 34 hp. Power to weight calculations say I'm only producing 270 hp but corrected to altitude I make 304 hp. That's trying to move a 4600 pound truck.

To properly convert DA you need to know the elevation of the track, temperature, barometric pressure (corrected/sea level pressure) and humidity. The humidity isn't a big factor in DA but humidity is what determines vapour pressure. A high vapour pressure and you lose hp.
Dang man, that's so true.
I'm here in Denver, I went to the track, and remembered to check my time slips in the Density Calculator at home.
Anyway, Bandimere Speedway is at 5800' altitude. Having rained last night, it was kind of cool at the track.

Those numbers given out by the Sea-level Calculator, seem too high to me. The DA was at 15549' . That means based on what I ran today, it would've been 9.41 @ 135.99mph. At Sea-level. No way I would run those numbers under any condition.

Temp F. 74
Relative Humidity 54
Absolute Baro 24.01
R/T......................... .228 (bad!)
60'......................... 1.932
330........................ 5.661
1/8........................ 8.704
MPH....................... 81.39
1000...................... 11.283
1/4........................ 13.458
MPH....................... 104.56


Goose :)
Racing with Altitude!

I already see a problem in your calculations. Barometric pressure is in absolute or "station pressure" Density altitude formulas normally use the corrected pressure. That's what your local weather forecast gives.

Recalculating your results from my own formulas I come up with 29.74 as the corrected sea level pressure (not a good pressure for racing). That gives me a density altitude of 8498 feet. Typical race day in Bandimere.

I already see a problem in your calculations. Barometric pressure is in absolute or "station pressure" Density altitude formulas normally use the corrected pressure. That's what your local weather forecast gives.

Recalculating your results from my own formulas I come up with 29.74 as the corrected sea level pressure (not a good pressure for racing). That gives me a density altitude of 8498 feet. Typical race day in Bandimere.
That's more likely. I think my car would go about 12.1-12.2 or so at 109mph at sea-level.
-Goose.

He zhevy-1 if you really want a little faster time slip you could drive over to julesburg co...but then again there track prep probably isn't as good as bandamere's. I want to race at bandamere sometime since its only 2 1/2 hours away but i need to fix my car first!!

He zhevy-1 if you really want a little faster time slip you could drive over to julesburg co...but then again there track prep probably isn't as good as bandamere's. I want to race at bandamere sometime since its only 2 1/2 hours away but i need to fix my car first!!I may give it a shot, before the Summer is over.

-Goose.