Adjusted altitude calculations/ went to Numedia today.

[RichS]

Without a weather station is there a way to calculate the adjusted Altitude? I ran at Numedial today and the conditions were : Temp: 72, Rel Humidity 92%, Absolute Barometer 29.92, actual track alt. is 750. Wondering since I'm usually .30 slower at Numedia vs. Englishtown for simular weather conditions, So my 11.82, 11.88, 11.84 would have been in the 11.6 range at E-Town. Man they preped the track good today. I got a best of a 1.67, with a few low 1.7s. There was a 63 Vette with a 427 small block with a turbo (1 or 2?) making 2100 hp, running a sick and scarry 7.0@202 The car is unreal!!

[CFI-EFI]

NHRA only factors physical altitude, and not for any tracks below 1600 feet. I imagine there are formulas to make that adjustment. The various weather station makers use their own calculations for DA. Each believing THEIR formula is the most usefull to the racer. With that moderate temp and high barometer, I'm guessing the DA was probably pretty close to 750', maybe 1000'. A rule of thumb provided by Altronics, is the an increase of 200' DA is worth a .01 loss of ET. Even a 1000' difference in altitude should only produce a .05 ET change. I'm curious why you normally see a .30 difference.

RACE ON!!!

[RichS]

Not sure why the track is always slower. E-Town is 60ft, Numedia 970ft. Everyone that goes between the 2 tracks goes .2-.30 faster at E-Town also with the same temp conditions. It can't bee the track prep because I get my best 60's at Numedia. I heard before the track has a slight upgrade from start to finish but I doubt that.

Last time at E-Town the Adjusted Altitude was +2100 and I went 11.88. So I'm looking if the AA was simular today. That day is was very simular conditions with less humidity as today here.

[RichS]

NHRA is in Mempis today. A track at 540' with today,Weather conditions: air temperature 78 degrees, relative humidity 80 percent, barometer 29.63 inches, adjusted altitude 2,046 feet.

I know there is a heck of a differance running E-Town in the summer with a CA of +2000 vs fall air and -2000. A good .40

[CFI-EFI]

Originally Posted by RichS

I heard before the track has a slight upgrade from start to finish but I doubt that.

There COULD be a difference in elevation changes between the two tracks. Numedia could be up hill, and E-Town down hill. Both could still be within specs, and it would still make a difference. The length of the tracks could vary, also. Your (and everyone else's) ET differences are too great to be due to only 910 feet of elevation. I've heard of tracks that "grease the clocks" for better ET results for their racers.

RACE ON!!!

[0ski_dwn_it]

rich.

So Numidia is running the track pretty well....lots prep, even on T&T days? If so I might have to make a point of heading the extra hour out there one of these weekends.

You should be able to pull low 1.5s with your combination. Are you running slicks? What kind and pressure?

I just scrubbed another .05 sec off my 60' times to make it a best of 1.481sec.

As for your ET correction, I can almost assure you that you will run .2sec quicker at Etown than Anywhere we have available around here in PA. I ran Numidia, Keystone, Dragway, Beaver, Mason the one year with my 350 and the best it did was 12.9s inland, most in the 13.0 range. Went to Etown for the last runs on the motor and it ran 12.8s EVERY run. Those guys have some tremendous air.

Its not called the mine shaft for nothing.

[RichS]

Hey Jessie, Sunday was a points day and they preped the track awsome. I keept raising my launch RPM and it held each time with a slight bog. Were in the procces of talking with the new owner to try and rent the track out on a Sat once the weather starts to cool off. Looks lik we can get it for 5 hrs before the Sat night session.
I'm running BFG drag radials still since I like my rear to stay together for at least one season!

I know E-Town is allways good for a easy .20 in equal weather. If I was there Sun I would have started beating my old best runs.