MembersPage/KarlBuchka/Fuel (2008-09-26 03:52:29)

Original intentions of running Delphi 1000cc injectors was scrapped. A friend offered me a set of used Siemens DEKA 1 795cc Low-Z injectors for a great price. Specs (from http://www.racetronix.com/3145FM.html)

Static Flow Rate: 74.7 lb/hr = 9.42g/s = 769 cc/min (+/-4%)

Dynamic Flow Rate 2.5ms PW @ 100Hz: 16.9 mg/pulse (+/-4%)

Coil Resistance: 2.35 Ohms / Low Impedance / Low-Z (Peak/Hold driver circuit required)

Spray Pattern: Pencil

Connector: Minitimer (Bosch EV1)


MembersPage/KevinBlack/InjectorSpecDatabase has a complete looking set of these numbers for the Delphi 95lb/hr injectors. Mirrored here:

Delphi Low-Z 95#/hr (with 30v TS diode and 6R8 resistors)

Barring any new information I will use these as base values for the Siemens injectors. Any suggestions on the figures?


The low-z injectors will require power resistors. As mentioned earlier, I can source them in almost any spec I want. I understand the resistors are used for current limiting, but how much current am I aiming for? A couple of quick calculations yields a 12ohm resistor for a current of 1A and 5ohm for 2A (both assuming 2ohm injector resistance and 14V supply).

PhatBob's UserGuide states that 6.8ohm/50W power resistors yielded good results on 'Delphi 1000cc injectors'.

I have opted for 6R 50W power resistors due to cost and availability.


I calculated req_fuel to 3.75 using (6.49 * 2300[cc] / 5[cyl] / 795[cc/min]).


As of now I plan to use my current Megasquirt fuel map (with values scaled) as a base map.