Jetting

[LIS20]

As the temperature goes down -- do you go up in jet size (ex. 80 to 82) or down (80 to 79)?? I have a new engine nd i do not want to lean it out

[rcstreet1]

Go up when the temp drops

[sj valley dave]

You can go on line and get an air density formula. You plug in air temp, altitude above sea level (static), humidity and air pressure and you see what real density is...We have raced at a track that is 350 ft above sea level, but due to temp, humidity, etc, adjusted altitude was 6,500 feet, so we leaned the engine down as there was not "as much" air for the engine...Willy's recommends one jet size per 1,500-2,000 feet of elevation change..

[fast_crew]

I don't suggest changing jets based off temp alone. Actual elevation, Baro pressure and humidity play a bigger role. Either do as Dave mentioned or invest in a hand held type weather station.

[chevy370lsx]

Install a wideband sensor, stay in the 12.5-12.8 range.