Discussion and questions related to the course Practical Standalone Tuning
I am looking for retrofitting and E9 Bmw 3.0 stock equiped with Djet Injection.
Unfortunatly in Djet, injector are directly connected to negative and ecu switch +12V.
Exactly the reverse as all the systems is know : megasquirt, maxxecu, haltech, rusefi/speeduino.
My friends (Bmw owner) don't want to change stock wiring, and want to stay stock look. So no possibility to modify harness (grrr).
Do you know any standalone that can switch +12v to trigger Injectors?
Or have i to get an scope and made a pcd with transistors to change - into +12V?
I wouldn't think modifying the harness to look stock would not be very difficult. You only have to modify the wiring just where the first injector branches off.
i know i propose him to made adaptator between stock harness and injectors but he don't want (Bmw owner :) )
Surely you could reverse the polarity on the circuit at the ends where nothing will be noticed, provide ignition switched power through a relay/fuse at the "earth" end and ground the ecu end through the injector outputs on the new ecu?
If not you can probably find solid state relays to switch positive power to the injectors driven by the ecu injector earths with very low response time which is either negligible relative to injector response or can be added to the injector dead time values.