Ignition settings on idle?

How do you know when to stop adding timing to idle ? I have entered around 20 degrees and the car seems to like it. I can keep adding more though, but idle gets higher and higher when do i stop adding?

You want to pull it back a bit after you've passed your target idle so your idle control can take over

The ECU that you are using and how the idle strategy works will also make a large difference. For example, with a MoTeC M1 the timing set in the base ignition map around the region of the map that the engine idles at sets the upper limit that the idle control system uses, so if you only have 5 degrees advance in there, then that is the maximum that the idle control system can use. If you then raise it to 20 degrees, with an Idle Aim of 10 degrees and the Advance Minimum set at 0, then the Idle control has a 20 degree range of timing to use for idle control.

Other ECU's that I have used require the setting of the base idle map in the main table, and then use this value for the Idle Aim and swing either side of this point, and some have a totally separate ignition timing map that activates when certain parameters are met, such as TPS and Engine Speed, so you need to know what the ECU is looking for regarding the ignition timing for idle.

I personally try and avoid using timing values lower than 5 degrees BTDC, as I find that having the timing more retarded that this introduces too much heat into the system if the engine sits in this region. It can be useful though for cold starts to get the ECT up quickly.

my car seems to like 20 degrees is this normal?

What ECU are you running? Have you calibrated your triggers for TDC? so that the ECU reads the correct timing before going any further?

If you have checked the base timing and made sure that if the ECU is requesting 10 degrees advance, and that is what is being delivered, then 20 degrees of timing may be correct. The engine may want 20 degrees at idle because the throttle is closed more at idle with the aftermarket ECU in comparison to the OEM, and thus is needs timing to maintain the targeted idle speed, or there may be parasitic drag in the system that means that more torque is required to maintain the engine speed. There is no hard and fast rule as to what is the idle timing figure, it is what the engine wants that sets the timing.

my idle is a tad high I'm going to turn it down to 18 or so, man theres so much to retain hahahah. I wish I knew how to tune lol. But yah, I'm running a haltech elite 2500. I synced the ignition timing bang on. If that's what you guys were getting at as well..

Not sure which timing numbers to put in the ignition map now, I smoothed the transistions out a bit, and made sure my timing numbers were very low in high rpm high load as I want to do that on the dyno with a experienced tuner.