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MoTeC M150 Harness build for MKIV Toyota Supra

EFI Wiring Fundamentals

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Discussion and questions related to the course Motorsport Wiring Fundamentals

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Hi All. I have started the Motorsport Wiring classes and need some professional assistance. I am in the beginning steps of a pretty large scale build for my 1994 Toyota Supra. I am seeking assistance regarding the wiring, connectors, wire ga (size) selection, circuit planning etc. I will link a spreadsheet that is pretty detailed so please reference that.

The basics of the build

MoTeC M150 with ProDrag Firmware

6 FIC 1050cc Injectors

6 FIC 1700cc Injectors

6 IGN-1A Haltech Ignition Coils

OEM Crank and Cam sensors

5 BAR MAP Sensor

IAT Sensor

Fuel Pressure Sensor

Transmission (T56 Dogbox) Input shaft speed sensor

Transmission Oil Temp Sensor

Diff Oil Temp Sensor

Turbo Speed Sensor

Exhaust Backpressure Sensor

Ambient Air Temp Sensor

Oil Pressure Sensor

Oil Temp Sensor

Coolant Temp Sensor

Coolant Pressure Sensor

Strain Gauge Shifter

VVTi Cylinder

Flex Fuel Sensor

Drive-By-Wire

MoTeC LTC Wideband

MoTeC 8 Button keypad

Where you see "Firewall Connector", I plan to have a bulkhead Autosport connector (Open to 1 or 2) mounted to OEM ECU wiring part of the firewall. I plan to build a secondary harness for the interior of the car to handle things like the strain gauge, fuel pump PWM, CAN-Bus items, etc.

I would like some assistance with making sure I have the correct design idea at the moment. For a majority of the harness, I have selectee 20 AWG M22759/16 Tefzel wire from YourSpec with laser marking on the wiring. From what I understand, I should isolate the 12 volt grounds so no sensor shares ground with either the ECU itself or the half bridge pins.

As far as the IGN-1A coils, I have read all kinds of conflicting information. I've read to feed all 6 coils with a single 10 AWG power wire. Then I have read that it's ideal to split them into pairs of 3 and feed 3 coils with a shared 20 AWG 12+ feed, then the other 3 with another shared 20 AWG circuit.

Now how about the fuel injectors. Is it best to feed each 6 injector set (12 injectors total) with a dedicated power and ground? If so, AWG size?

The M150 has 3 12 volt positive pins (B13, B19 & C26), for reference.

I will stop the explanation here to see if this post gains any traction.

Thanks!

Attached Files

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