I live where it's about 5500 feet above sea level. I have an air/fuel ratio gauge so fuel mixture is easy, but I want to know how much more timing to put into the motor. I was talking to a guy at the track and he was telling me that at our elevation we could run alot more timing that the guys at sea level. I was running 12 initial and about 34 total by 3500rpm. I then bumped it to 14 then 16 and my car kept running better. I am running almost 40 degrees total and the motor runs great. I wanted to try more but you could feel the starter fighting to start the motor so I left it. I have vortec heads with flattop pistons on a 350 block that is bored .040 over and even with like 10.3:1 compression I have never heard even the slightest engine knock. How much timing are you other high altitude guys running?

 

1 degree more advance for every 1000' in elevation is what I've heard.

I'm running my LG4-based system at 10 degrees base (factory is zero). But, I have a knock sensor system, too.

Bottom line is to run as much total advance as the engine wants for best performance. If you're getting starter kickback, you need more mechanical advance in the distributor (or the MSD start retard system).

 

Good to know, Thanks.

 

When I used to live in Alamogordo (~4400 ft), I was able to advance my initial timing to 10* with no pinging. Same with my friend's 5.0 Mustang, we advanced his quite a bit with no pinging.