[Formulajones]

I can relate to the air qualities at these desert type tracks in different locations. I race in Phoenix the most but I've been to Sacramento Raceway which is just 50 feet above sea level.
Definitely a big difference in how the car runs.

One particular car I've raced at Phoenix a number of times would run 13 teens at 112 mph. Sometimes a 13.0 would pop on the board depending on how I drove it (stick car with street tires).

Funny story. We drove this car to visit family in Sac and while driving around town a lane was ending. I jumped on the gas to move over and it was like a light switch, busting tires loose, switching lanes without my approval. My wife looked at me and I just said, don't blame me the car never does that. That's what happens when most of the time you're driving around a mile up in the atmosphere and suddenly you're at sea level. It's a different car.

For giggles later that week we ran over to Sacramento Raceway for a few test and tune passes. Right off the bat, 4 passes were 12.80's with a 12.76 best, and all were 115+ mph. This thing has never been 12's. After driving back home to Arizona I did get the car back to the track where it was plagued with low 13's again.
I don't know what it is about the Phoenix desert air even though our track is only 1000 ft above sea level, but it's tough to get a good DA here. All the cars I also raced when living in Ohio ran faster out there too, and they have all slowed down a tick running in Phoenix.