Just for those who are interested, I installed a DET3 in piggyback mode on an early 3000gt/GTO Twin Turbo.
DET3 Function ECU
Pin 1 12V Pin 12
Pin 11 Ground Pin 13
Pin 3 +10 MAF Input Pin 70 (Harness/Sensor Side)
Pin 7 MAF Output Pin 70 (ECU side)
Pin 8 + 9 Crank Input Pin 69 (Harness/Sensor Side)
Pin 6 Crank Output Pin 69 (ECU Side).
Configurations
Under Setup Tables
Fuel Table
Freq
Freq
Disable
Disable
Ignition Table
Freq
Disable
Disable
PWM 1/2
Freq
Disable
Disable
Under Ignition Configuration
Retard Single Signal
Hall Effect or Optical Sensor
Maximum RPM
7000
Num. Signals per 720
6
Maximum Retard
15
Under Frequency Configuration
Modify Frequency Input Nonlinear
Freq Min
10
Freq Max
2700
Base Unit
4
RPM Multiplier
1.0
The only thing I'm notsure on is Freq Min 10, and Base Unit 4.
The car did run pretty smooth after install, so it should be fine.