Installing a VEMS unit on a stock 89 Porsche 911 Carrera 3,2.
Open issues:
- Tuning ;-)
Engine specs
- 3,2litre flat-six normally aspirated
- number of cylinders=6 (even fire)
- trigger system is 2 VR sensors on flywheel / starter ring gear (crankwheel)
- rev sensor is sensing 129teeth per crank rev
- 43*3, so divide-by-N N=43
- the rest like reference tooth almost like with 3 teeth on the crank: a c003 trigger if sectrig comes just from 1 crankpulse, ( or c006 if camsync is also installed - which is not, at least initially )
- TDC sensor is sensing 1 pin on flywheel (don´t know yet how many degrees before TDC).
- Will likely need to have (access to) a strobelight to verify all is well.
- rev sensor is sensing 129teeth per crank rev
- no cam or distributor sensor
- with auditrigger camHALLinverter the EC36/13 input must be grounded to allow the crankhome-VR pulse to go through.
- stock NTCII at cylinder head #3
- AFM (flap type) will be removed, will use TPS instead (exchanging stock idle and WOT switch)
- idle control valve is the "silver cigar" BOSCH thing, two wires to ECU, so PWM
- IGN distribution will remain untouched in first step, stock coil, stock distributor
- stock fuel injector BOSCH 0-280-150-158 low-Z (2-3 Ohms)
- order with "low-Z extension" option if you keep the low-Z injectors (and configure PWM-ing: ~35% PWM duty after 1msec full-voltage)
- wideband O2-sensor will be used intead of stock narrowband
- no MAP.
- It would be easier to tune with a MAP sensor, but also possible with TPS, with more work
- MAT now planed
- The MAT sensor is almost a MUST (in a normally aspirated engine MAT sensor can be an NTC in the air-filter, very simple and cheap, just make sure the engine will never inhale it)
- Firing order is 1-6-2-4-3-5 for the Carrera
- wiring should remain mainly stock with stock-DME-connector and only additional wires for wideband, TPS and so on
- planning to use alpha-N only
VEMS-spec: / Needed parts
- VEMS Board version v3.6
- Serial nr.= 8234
- (Order ID= 8044)
- Flyback: Low-Z-active flyback 8ch
- ignition driver: 8
- primary_trigger: EC36/27 VR
- secondary_trigger: auditrigger w/camHALLinverter
- Knock input channels: 0
- LCD connection: no
- MAP connection: offboard(electronic)
- mounting-style: no-screws
- 1-wire interface: no
- EGT input: no
- PS2 connection: no
- withSDcard: no
- Other stuff:
- DME-plate with 35-pin-connector DIY
- TPS from E36 (Hella): 6PX 008 476-111
- TPS Adapter plate DIY
- WBO2 (Bosch): 0 258 007 351
- MAT (Bosch): 0 280 130 039
- intake pipe with MAT thread DIY
- 1 x Wideband connector
- 1 x Econoseal18-Wire side
- 1 x Econoseal36-Wire side
- Some other connectors etc.
- A lot of enthusiasm and time ;-)
Related projects by other users:
Looks like a similar setup: MembersPage/KevinBlack/PorscheTurbo