The ProMAX Performance chips for the 928 S4, GT and GTS models have been extensively developed to provide not only a power increase, but also improved smoother running.
All flat spots and anomalies have been engineered out of the original compromise chip (ECU EPROM). To ensure that emissions are not effected, changes beneath 3,000 rpm are minimal. The timing curve on these chips is substantially smoother than the original with the often pronounced step in the mid-range made more progressive.
Power gains at the top end are between 5-14%. Power increases of up to 18% have been recorded on cars fitted with a modified induction system and free flowing exhaust (with cat bypass). NOTE: 2 chips are supplied for the 928 - LH (fuel injection) and EZK (ignition ECU). NOTE: Only available for 32 valve models (S4, GT, GTS).