Ignition tuning with a distributor

Hey Andre,

Can you please explain how you go about tuning ignition advance on an engine that is fitted with a distributor ignition system? Is there still a 3d table which is tuned just like you did in the dyno and road tuning courses? Or is the ignition advance set at one specific value for all operating conditions by where the distrustbutor is physically set?

Can you shed some light on this a bit?

Thanks.

Distributor rotor has a wide tip, which provides an ability to advance or retard ignition over the base distributor position. So you can use a 3D table as with DIS ignition systems. Of course you can`t retard or advance over the tip length

Nothing really changes when you are tuning a distributor ignition system compared to waste spark or direct fire ignition systems. The only issue is that your range of ignition advance becomes a little more limited because if you advance or retard the timing too far the rotor arm won't be aligned with the ignition post and you will end up with crossfiring inside the dissy cap.

This isn't typically an issue to be honest provided you're working in a normal range of ignition timing - Perhaps 0 - 40 degrees BTDC. It does however mean that functions such as antilag or aggressive launch control where you are relying on large amounts of ignition retard may not work with a distributor.

It's also important to make sure your static rotor alignment is ok. By this I mean that you want to align the rotor arm so that it is just about to leave the post at the most retarded ignition angle you're likely to run (normally I'd do this at TDC). This ensures that when the ignition angle is advanced, the rotor arm alignment will be correct.