HEy guys i have a professionally built holley carb. it flows around 900cfm.

i have my timing set to 36* at 3000 rpm. at the track we had to richen up the carb one step because it was running lean.

we got it to where it was running 13.1 -12.8 at wot in high gear. today i go to test it out and its reading 14.2-14.4 today.

it was very humid at the track that night, however it was humid today but not as bad or as hot.

Any ideas?

I have a 383 with dart pro 1 platinum 200cc heads with a mild valve job.
comp cam x282hr cam. rpm air gap intake 1' spacer and ya. compression is at 11:1.

Im wondering if i should lower timing 2 degrees or so.

 

you can try 34 degrees. newer heads like less timing due to better chamber designs but all setups will differ.

weather will change your air fuel ratios due to o2 content in the air. higher pressure conditions outside and cooler air makes for denser air charges so you get more o2 into the intake.

 

so hotter will mean less air and richer. cold air is cooler and leaner

 

basically but by how much i'm not sure

cold air will pack more air in and less fuel so your leaner. funny thing was my car picked up alot of time in the cold air last year but i was very lean at 14.5 to 1 !! summer time i must have been leaner and had no idea! dangerous