Idle Speed. What makes it right?

Kent mosby said

The variables are all easily set in the sniper software. The question is where to set them.

Maybe I should have broken it down to -
When setting the idle timing, what parameters do you look at? Vacuum, idle, surging, lugging off idle???
When setting AFR, What parameters do you evaluate first, second and so on? Idle quality, stumbling, Plugs etc.
When setting Idle speed, What is your primary consideration? Smoothness, vacuum, stumbling off idle, etc...

I understand that all parts must come together and that you will go back and forth to get it right. How do you approach the initial setup?

Click to expand...

I’m sure some tuners follow some kind of self imposed process but really it is a process that is learned and experience makes a big difference. On the few Ive done for myself I plug in some numbers that I know will get it to run. At 13:0 afr 16deg initial timing almost anything will run. Once the idle afr is stable, safe, and kinda rich I’ll bump timing small amounts and watch rpm and vacuum while pulling idle air to keep the rpm the same, usually targeting 1000 on new tunes. Then start trimming fuel to get the o2 correction in line. Once the ve table is close at idle and o2 correction is minimal your idle afr will closely match your target. When your targets match with little correction from o2s then you can mess with target Afr. It’s not just a “set it and forget it” process. You have to move around the tune for a while to find out what the engine likes.