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SPARK MAP

The AFR table is a 3×3 matrix – the AFR is interpolated between these breakpoint values. This means that if you’re breakpoints are 45kPa at 14:1 and 95kPa at 12:1, operating at 70kPa will result in 13:1 target.

Distrib Base deg = Adjust this to get the timing light timing to match the displayed Spark Advance at low RPM. It’s recommended to set this as high as possible, because the amount of advance range from min to max is limited due to the rotor and cap being in a fixed relationship.

VR Advance 4000 = Adjust this to get the timing light timing to match the displayed Spark Advance at 4000 RPM. This is adjustment for the small lag inherent in VR signals. It can add up at high RPM.

Idle Advance = The spark advance desired at idle.

1100 45kPa = Spark advance used just after throttle opens from idle. This value shouldn’t be much
more than the Idle Advance, for this reason.
3000 45kPa Cruise = Spark Advance used in a light cruise at 3000 RPM and throttle barely open.

6000 45kPa = Spark Advance used in a high free-rev condition, perhaps also seen when autocrossing and just tipping-in in a low gear at high RPM.

WOT 1100 95kPa = Spark Advance at low RPM and “full load” – perhaps the throttle is as low as 20% to see this much load. Spark is based on MAP, and MAP (and thus “load”) can get pretty high even with low throttle openings at low RPMs.

WOT 3000 95kPa = Spark Advance at high loads and 3000 RPM. This could easily be deemed “total” timing when comparing to a distributor, but due to the flexibility of a 3×3 matrix, this doesn’t limit you as such.

WOT 6000 95kPa = Spark Advance at high loads and 6000 RPM. At high RPM, some engines require more or less spark advance than at 3000 RPM. This allows you to set the timing there.


Boost 1100 180kPa = This is full throttle but with a supercharger or turbocharger boosting to about 11.6 psi. If no intercooler is used, the engine may require very little spark advance. Remember that timing less than the base advance “Distr Base Deg” is not allowed, so choose the base timing carefully.


Boost 3000 180kPa = This is full throttle but with a supercharger or turbocharger boosting to about 11.6 psi. If no intercooler is used, the engine may require very little spark advance. Remember that timing less than the base advance “Distr Base Deg” is not allowed, so choose the base timing carefully


Boost 6000 180kPa = This is full throttle but with a supercharger or turbocharger boosting to about 11.6 psi. If no intercooler is used, the engine may require very little spark advance. Remember that timing less than the base advance “Distr Base Deg” is not allowed, so choose the base timing carefully.