BOSCH D-Jetronic Megasquirt Adapter Options

[shconer]

I have built a prototype board that adapts the factory Bosch D-Jetronic card edge connector in my 1969 Squareback to the DB-37 connector of my Megasquirt 2. Also I retrofitted the factory pressure sensor with a modern sensor inside. With some small modifications to the Megasquirt board to accommodate the external MAP sensor. I have created a plug and play system that works with the factory harness and does not require any further modifications or additions. Alternately you could instead connect the standard Megasquirt onboard MAP sensor with a hose to the manifold and lose the factory appearance. I have done some testing with the prototype board and I am in the final stages of developing the final version. I have designed it to be compatible with early and late type 3 cars as well as all fuel injected 914's. Before I ordered PCBs and components I thought I would see if there is any interest out there for something like this. The final PCB is designed to mount inside of the factory case with room for the Megasquirt. An assembled adapter would cost approximately $80 CAD. This could be a cheaper solution for someone with a malfunctioning D-Jet ECU or a dual carb conversion. The factory idle control system still controls idle. This is a fuel only set up and the factory distributor and ignition is used. Also there is no provision for EGO feedback, it is a open loop system. This adapter works with MS1 or MS2 V3.0/3.52.

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[shconer]

This adapter is mostly a passive device. Because the injectors are controlled on the high side the adapter has a MOSFET protected with a diode to drive the injectors as the Megasquirt is not capable of doing this and that is the only active part of the adapter. This does add some injector dead time but it has been very minimal in my testing. The final board will use surface mount components except for the capacitors, and the connector and will have some sort of conformal coating on it for added protection. So as far as experience, driveability, and tuning is concerned its really built upon the constantly evolving Megasquirt platform.

This adapter is designed for applications that want to retain the factory appearance. So its limited to stock or mild performance applications. Where the factory ECU requires replacement, or where modifications require more flexibility in the ECU. Any type of fuel injector can be used. The most limiting factors in terms of performance is the lack of ignition timing control which is a limit of the factory harness and the factory trigger system housed inside the distributor.