928 S4/GT/GTS (1987-1995)

V2.1 now shipping with refinements and fixes!

Individualized performance for your S4, GT, or GTS!
Automatically creates a custom advance map for EACH cylinder
Each cylinder is optimized for its own unique airflow and knock tolerances
More power across the rpm range at rpms not available when manual tuning

Custom tuning can be used as the basis of the new chip (EG. from a cam swap)

EZK new code highlights:
- 8 learned maps, 1 for each cylinder
- Soft rev limit, ignition retard (6400)
- Knock light/CEL enabled

- New knock sensors
- New CPS (crank position sensor)
- New TPS (throttle position switch)
- New hall sensor (cam position)

Recommended minimum octane:
91 US/AKI (95 EU/RON)

- EZK chip
- case label

Buy It! (in stock)


Q: What does EZK-S stand for?
A: Elektronische Zündung mit Klopfsteuerung - Selbstlernende/Selbstoptimierende
A: Electronic Ignition with Knock-control - Self-learning/Self-optimizing

Q: How long does it take the EZK-S chip to generate new maps?
A: About an hour for the initial learning, the entire map is filled in about four hours of driving

Q: How and when should I reset the learning?
A: Hold pedal to floor, turn key to ON, seasonally or when going up in fuel octane rating

Q: How does it drive while the EZK-S is learning?
A: May feel flat at certain RPMs but becoming smoother and more powerful over time

Q: Why does the exhaust sound different?
A: As ignition timing is optimized more power goes to the wheels vs. wasted as noise

Q: What is a soft rev limit?
A: At the soft limit power is reduced so that the hard fuel cutoff cannot be reached

Q: Where is the CEL?
A: 89-95 have a Check Engine Light which just needs a bulb installed (red B8.4D)
A: 87-88 can wire a 12V bulb/LED to the diagnostic plug

Q: What information will the CEL show?
A: Knock and hall sensor errors, knocks, and if the learning has been reset

Example of four cylinders versus stock timing after a couple of hours of driving