more or less timing for cammed cars

[huttler]

i've been scanning through posts and i'm getting conflicting information about timing for cammed cars. I think the general idea is this:

if the specs of a cam are (for example) 114 LSA 224/228 then i would advance the timing to 34* in idle zones (0-800 rpm, 0.08 - 0.32 cylinder airmass) and advance timing 1-2 degrees in all other ranges.

[EC_Tune]

Generalities don't take into account deck height, cam/crank sensor error, chamber cc's etc. All of those add up to a custom tune that is "just right" for your engine.

34 degrees with a 224 cam is getting up there. I would start out low and work my way up by watching the manifold pressure. When the MAP drops a to it's lowest point at idle that's the sweet spot, no more timing is necessary. You can test this with the VCM Controls in the scanner.
Don't crank in too much timing or you can get an unstable idle. Sometimes less is more.

[Alvin]

yeah, 34 is way to much. use map as a indication of where to go with your timing at an idle.

[WS6FirebirdTA00]

Yeah use the VCM controls to play with the timing, just give it time to become stable in between changes. Once the MAP reading seems to bottom out that will be a good range. You will get to a point where more timing will barely change the MAP.

[Billiumss]

Good info, will this help with some idle surging and or dipping when you push the clutch pedal in if your MAF, VE and RAF is just about perfect?

[WS6FirebirdTA00]

if the rpms come down too fast and dip, you need to log your throttle cracker and follower to see what they are doing. Throttle follower should be zeroed out before you get to your idle rpm. Then you have to see how and when it dips below idle so you know what needs to be adjusted.