I’d like to run a flat 10 degree map for months. How safe?

YES, it’s an extreme example, but on purpose. I don’t have access to the dyno, but I’m very confident at dialing in everything BUT the ignition timing. I’m another level of conservative and playing it safe.

To eliminate any chances of knock until dyno-time and proper equipment (aside from properly calibrated knock sensor), could I just run 10 degrees across the whole map, idle aside?

Reason I ask is, lower ignition promotes higher exhaust temps. What is the danger if any?

Why don't you run the stock OEM ignition map for the engine or something close. That would have been tuned to be conservative. want more safety, then remove 4 degrees everywhere in that map.

Removing too much of ignition timing for a long period of time is not very good idea... It hurts your fuel economy, power and overheats the exhaust valves and runners which can lead to cracking....

Thank you for such prompt response, it's a 200K miles Honda (F22C) with 13PSI supercharger on a mediocre tune.

Only reason I'm concerned of running the OEM ignition/spark timing is I am centrifugal-supercharged at 13PSI with 93 octane @ 150 AIT.

Do you suggest I take OEM ignition map (I know it) and subtract say 5 degrees across the board. Then take boost+ areas and subtract another 2, 3, 4 hell... 5 degrees per PSI until it safe?

Many Thanks,

-Dmitriy

OEM ignition timing is for natural aspirated engine. Since you are adding boost you need less ignition timing in boosted areas of ignition map. You can leave your na ignition map area unchanged but reduce ignition a couple of degrees every 1 psi of boost in boosted area of the map. 3-4 degrees of retarded ignition timing per psi of boost should keep you in the safe zone providing that octane rating of your pump gas is high enough (93 or higher). Anyway, it would worthwhile to double check fir any sound of knock at high loads with a set if headphones and a metal tube attached to engine.

Balshoyie spasibo.

-Dima