spark table timing question

[mobythevan]

Ok, I need some input on my spark table for the 4G63 engine in the talon. I am trying to understand better why the L28et has idle timing set around 20 BTDC and then ramps up from there, but the 4G63 has idle timing at 5BTDC. I can see that the stroke and chamber design (swirl/air fuel mixture)) will affect timing, but is there anything wrong with setting the idle timing on the Talon at 16-18BTDC and ramping up from there? And why does the factory ECU keep timing so low at idle?

[yo2001]

It's got to do with the compression/VE and emission, also ECU adds 5 more degree of timing at idle with total timing of 10degree. most of DSMer's with stock or smal turbos run more initial timing around 10degree (with ECU bypassed) with no problem. Just check for the knocks.