SharkTuner Mk1

Info about the Mk1 SharkTuner for 85+ cars

The JDS Porsche SharkTuners for the Porsche 928 allow the optimization of the fuel and ignition maps to ensure optimum performance from the engine. The original SharkTuner Mk1 connected via a "ribbon cable" to the ECU for 85+ cars, the new SharkTuner-2 replaces the original ROM's with programmable memory modules ("PEM's") and connects via the diagnostic connector for 87+ cars.

This page covers the SharkTuner Mk1, for info on the SharkTuner-2 see this page. Complete information on the SharkTuner family is available on the JDSPorsche website.

The SharkTuner Mk1 can be connected via a ribbon cable to the ROM socket for 85/86 cars, either to the LH2.2 or EZF ECU. For 87+ cars, the ECU's can be connected the same way, via ribbon cable to either LH or EZK, or the ECU's (either or both) can be fitted with PEM's (programmable memory modules) and the SharkTuner connected to the ECU's via the standard diagnostic connector. In either case the SharkTuner is a hardware interface between the LH ECU (fuel injection computer) and/or the EZF/EZK ECU (ignition computer) and a laptop computer. A slave microcontroller in the SharkTuner acts as an interface between the laptop computer and the ECU's, and a custom Windows program running in the laptop provides access to both the LH and EZF/EZK ECU's for real-time diagnostics, adjustments, and data logging. For tuning, a wideband-O2 (WBO2) sensor is required to provide a measurement of the air/fuel ratio (AFR).

Here is the Sharktuner Mk1 user manual for more information (click the link to open, right-click to download). Read the manual first, it makes everything much more clear!

Sirius Cybernetics LLC is an agent for JDSPorsche for SharkTuner sales and support for the Americas, Australia and Asia. (For sales in the Mideast and Europe, contact JDSPorsche at We are also the developers of the Sharkplotter software, which allows post-processing SharkTuner log files to update fuel and ignition maps-- no longer do you need to drive with one hand on the keyboard and the other on the wheel.

The Sharktuner Mk1 is available for all cars from 85 (LH2.2/EZF) and onward, and comes complete with ribbon cables and adaptors for direct connection to the ROM socket for both 85/86 and 87+ cars plus a diagnostic cable for '87+ cars (specify year), for $1990 plus shipping. This, and a WBO2 sensor, are all you need to tune and diagnose the LH and EZF/EZK. PEM's are an option for the '87+ cars for $100/ea, one each required for the LH and EZK.

To place an order or get a shipping quote, please send an email to:

Happy tuning!