Spending 20 min on google and finding diddly will make you want to light the computer on fire!
That being said.. I was wondering if anyone had info on even rough correction factors for either ET/MPH or hp from a given temp to more normal temps.
It's been like 40 deg here lately, and I was wondering how that compares to a 70 deg day..

matt

Humidity and air pressure figure so heavily into the equation that I don't think you can go only by temperature. There probably is a "rule of thumb" but I don't know it.

Marv & Pat,
Here's a site with lot's of correction calculators you can play with ;)

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

Wow, that's complicated. I was also wondering how 47 degree, but humid air, compares to 70 degree dry air.

The only way to perform corrections is by using density altitude. DA takes into account temperature, dew point, altitude, and pressure (really altimeter), Here's a link to a calculator I use frequently:

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

The is also a great weather site called anything weather (http://www.anythingweather.com/) that keeps archival data including the above info.

Another good site with daily (read no archival data) weather reports that include already calculated DA is here (http://www.wx-now.com).

Once you have your density altitude you can use the standard NHRA correction factors (http://www.prestage.com/Tech+Info/Drag+Racing/351.aspx) to determine what your car might have ran at sea level. These correction factors are just a reference. I've found that air effects each car differently. Sometime my car will slow down and my buddy's car will pick up. The tune on a car can be greatly affected by changes in the air.

HTH.