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Anti-lag ALS is it possible with wasted spark ignition setup

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Hi Everyone,

Due to limitation of the ECU model, we have only 3 ignition and injection output for a 6 cylinder straight engine which is turbocharged.

ALS anti-lag function would be necessary for this drift car, so it would be used in wasted spark ignition mode.

Is it possible to have ALS function with ignition retard method and opened/jacked throttle?

I am wondering in the pair cylinder, where the wasted spark event would occur, we would be in the intake stroke when we would have a spark event. Wouldn't this cause backfires into the intake side?

Kindest regards,


You couldn't retard ignition too far, might have to couple it with rotational fuel cut, probably wouldn't give the smooth off throttle coast you might want in a race car but might be ok in a drifter depending on driving techniques.

Is this using double headed coils, or four individual coils?

If it is using double headed coils, then typically this isn't too much of an issue (Mitsubishi used this manner of ignition on most of the EVO's and they ran ALS in Group N without issues) as the majority of the coil energy goes to the plug that is under compression. What energy goes to the plug that is in the chamber that is drawing the intake mixture in is usually not enough to initiate a spark event.

If you are using individual coils per cylinder, then you are going to get a full discharge on both plugs, this has the potential to ignite the mixture when the inlet valve is still open. This does require that there is a sufficient air/fuel mixture near the plug to initiate and maintain combustion.

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