SpiltTransFluid

Hi all. I live in Colorado (5280 feet above sea level) and my problem is this. I have an edelbrock performer 600 cfm with the factory jets. Does anyone on here know what size jets I need for this altitude? Nobody in my area seems to know this.... thanks

Apeiron

The process for tuning the carb is the same at any altitude.

Primetime91

iTrader: (15)

You'll be using leaner jets at higher elevation

Probably want to change the enrichment rods too

Damon

Most people overestimate how much of a change is needed due to altitude. Some formulas would have you go downabout 4 jet sizes vs. sea level. In reality, it usually only takes a change of maybe 2.

If you want to try some changes, keep them modest. Try going down 2 jet sizes (or 4 larger on the rods) and see how it responds. If you've gone too far, you'll be able to tell and can back up to the previous calibration.

Every engine is different and there really is no substitute for making small, incremental changes and "zeroing in" on what works best.

Modern stand-alone wideband O2 sensor systems can give you real-time data on where you are what effect a given change has made. Very handy for the serious tuner, but not cheap.