BlownHemi (2016-05-11 19:12:06)

After some consideration of my options, I'm almost set on going with VEMS for engine management. Anything that's cheaper is far less intelligent, anything that's more intelligent is also more expensive.

The car is an '89 S13 200SX w/ a built CA18DET engine. 1809ccm, 4 cyl, turbocharged, intercooled, multipoint sequential FI, COP ignition.

Aligning VEMS with the engine:

MAIN INPUTS

Air metering

Original

MAF

VEMS

4bar MAP + IAT (already have both)

MAP will be mounted externally, close to the IM, shortest possible tubing

5V supply comes from the ECU

IAT is a BMW type, res./temp diagram TBC

Crank angle, cylinder pos.

Original

mounted on EX cam, disc has two concentric rings for two optical pickups with OC outputs

(pulled on up ECU side)

Outer ring has 360 slits

Inner ring has 4 windows w/ lengths in slits: 16, 12, 8, 4 (not in this order, TBC)

(I don't yet know which window corresponds to which cylinder)

VEMS

using the same CAS with the "nissan 360 degree secondary trigger" option

Engine coolant temperature

Original

NTC regular type, 2.5kOhms at 20*C, 300Ohms at 80*C

VEMS

using the same

Throttle position sensor/switches

Original

Idle switch, closed when pedal released

TPS ~1kOhms - ~9kOhms for fully released, fully pressed, respectively

VEMS

using the same

Knock sensor

Original

1 channel, piezo type, mounted between #2 and #3

VEMS

using the same

O2 sensor

Original

N/A, stock narrowband removed, Bosch 4.x installed (probably 4.2, TBC)

VEMS

using the Bosch 4.x WBO2

MAIN OUTPUTS

Ignition

Original

Individual coil on plug, ECU outputs logic 5V signals for each cyl.

5V signals go to power transistors mounted in engine bay, these drive the individual coils

VEMS

using the same, putting out 5V logic signals

Q: how difficult to convert the IGBTs afterwards, if needed? (not likely, but still)

Injection

Original

lowZ injectors with dropping resistors mount in engine bay

VEMS

need possibility to drive either highZ or lowZ-s injectors, so "active flyback" option required

Q: do low-Z injectors still need dropping resistors?

Idle Control

Original

no idea, probably the same as any other Japanese vehicle from the same era, 2pin terminal

VEMS

using the same

Fuel pump control

Original

high side switch, probably, TBC

VEMS

using the same

Q: any "modern" features, like 6V operation, PWM closed loop w/ fuel press. sensor?

Auxiliary outputs

water pump PWM control for SSR (future)

[NOT YET FINISHED]