[Fot] High Altitude racing

[Bud R]

In theory if you're running a constant depression carb like a ZS then  
altitude should not make a difference since the less dense air should  
pull less fuel. In practice many cars that have come from lower  
altitudes have found they run too rich at Colorado altitudes (5280  
ft.) and above. Usually leaning the mixture helps.

If you run Weber carbs or something similar then you have to do  
correct jets and venturies to get it right. Yes it makes a big  
difference since we have about 5psi less air pressure (inches of  
mercury) than at sea level. So a supercharger (with 5 psi of boost) in  
Denver would just about make up for how my TR6 ran at Galveston TX, or  
Jekyll Island where I was in heaven with the kick in the pants the  
accelerator gave me at those sea level venues.

Bud Rolofson

71TR6 CC57365 (Good 6)
71 Spitfire MK IV Race Car #3
66TR4A CTC57529 (The Project)
71F-250 Camper Special (Triumph Support Vehicle)
Z-50A Hardly Davidson 1977 Honda Mini-Trail Bike (Triumph Pit Bike)







On Jan 30, 2013, at 2:59 PM, Robert Johns wrote:

> but he was way too rich.  From memory,(
> that is a long time ago)  Los Alamos is 10,00 feet and tuning for that
> altitude made the big difference.