Originally posted by rmcd79:
Going out and racing someone heads up is fine because you both have the same conditions to work with, but the way your comment came off it sounded like you thought conditions didn't matter when comparing a time from Denver and a time from sealevel.
Yes, but this is the problem. Apples are being compared to oranges here. Fergus (or Ferktek?) was commenting on different cars at different tracks. The times are not comparable without some type of correction which is not possible to obtain. It could be guessed at, but unless someone (and what a job that would be!) went out and tested every car manufactured at different tracks and different temperatures, you wouldn't know what the correction factor would be. Not all cars react the same way to environmental changes so an individual correction would have to be made for each car.
To make things a little easier to understand:
Car A is raced at Track 1 and gains an ET of 14.7
Cab B is raced at Track 2 and gets an ET of 15.8
Well, if there is a difference of 1000' ASL between the two tracks or a 10 degree difference in temperatures then the times are just not comparable. Car B might well run a 14.2 at Track 1. You would not know unless you drove to that other track.
Both cars have to be raced at the same track in order to compare their times. If you watch NHRA they don't say, "well Jimmy ran x.xx last week so he wins today!!" (BTW I don't watch NHRA - I like corners, in both directions).
There is one other factor the FL guys have missed. Super charging and turbo charging actually come from aircraft. It is a method of increasing manifold pressure to obtain engine operating conditions which simulate sea level. This is done to increase performance at the service ceiling, or to increase that ceiling.
You cannot compare a turbo-charged engine at sea level to a normally aspirated engine at >1000' ASL. It might be possible (again, each car would need to be identical) to assume (and I use "assume" very lightly) that a supercharger Contour racing in Denver would get approximately the same numbers as an NA Contour at sea level. This of course would largely depend on removing other factors such as track condition and temperature, and assume that stock, both engines produced exactly the same horsepower at the same location.
