Building a Porsche 3,0l 944 turbo
Now the details that affect VEMS specs and installation.
- original Bosch Motronic sensors will be used
- water temp x2 , oil press, knock
- exceptions are MAT and MAP, these will be from VEMS web shop
- original wiring loom will be used
- fuel injectors are SiemensDeka
- Static Flow Rate (GAS): 86 lb/hr @ 43.5PSI (300kPa) = 903cc/min, 10.88g/s
- Coil Resistance: 2.35 Ohms / Low Impedance / Low-Z
- Ignition for starters wasted spark, with option to COP
- TPS will most likely be the one that comes with ITBs
- For trigger see below
Trigger
Porsche 944 turbo trigger:
- 132teeth on flywheel -VR sensor
- Crank home (1 pin on flywheel 24.5 tooth, ie 66.8 dec BTDC 24.5 x 2.7272 deg, if i remember right) -VR sensor.
- No cam sensor
- And no missing teeth anywhere!
I.e. trigger is 132+1
Here's a screenshot of my triggerlog made into a graph, nice and steady signal. So VEMS can be installed to a 132+2 system with 2 VR sensors and without cam home hall sensor.
Shopping list
Assembled v3.3 controller
- 1-wire interface no
- ignition driver 4
- Knock and EGT yes
- LCD and PS2 yes
- MAP connection 400kPa onboard (6/4mm pneumatic)
- mounting-style screws
- PowerFlyback yes
- primary_trigger VR
- secondary_trigger Auditrigger
- EconoSeal36-Wire
- Econoseal18-Wire
- EGT sensor (K-type) Size 6mm
- K-thermocouple connector
- mounting-style panel-mount
- Sex pair
- mounting-style flyback
- Sex pair
- Wideband O2 sensor
- Wideband connector
- With wire with crimped wires
- MAT sensor
- Pneumatic valve 3way
Specifications:
Board_version=v3.3
Serial_nr= 748
pump-= 4.16V
wbo2_pump_pw_zero=0x67
wbo2_nernstdc_target=0x86
pump+= -3.3mV/200 Ohm
AREF=4.9V
(C103=1nF, no D100)
Firmware 1.1.24
http://www.vems.hu/download/v3/firmware/
Part of config, I'm running this trigger with div_by_2 with these settings:
primary_trigger=C3
secondary_trigger=19
tooth_wheel=42
trigger_tooth=01
another_trigger_tooth=21
crank_minper=33
tooth_wheel_twidth1=20
tooth_wheel_twidth2=00
cam_sync_r_edge_phase=00
cam_sync_f_edge_phase=00
reset_engphase_after=40
ign_tdcdelay=7F
ign_dwell14=27
ign_dwell6=CC
ign_crank_advance=20
ign_out=70
ignchmax=03
Auditrigger was initially according to PhatBob's instructions:
EC36#27 VR+ ( primary ) = CRANK speed sensor
EC36#13 VR+ ( secondary ) = reference sensor (whel HALL!)
EC36#26 VR- ( primary & secondary )
but changed to
EC36#27 VR+ ( primary ), = CRANK speed sensor
EC18#12 VR- ( secondary ), = VR reference sensor
EC36#26 VR- ( primary )
EC36#26 VR+ ( secondary )
after discussions with Miska. So installation instructions should be updated considering this part.
Configuration:
Tables:
Pictures:
History:
Update 16-11-2007
Finally I've managed to get the car idling well, there's been both mechanical and program related problems. Now triggering issues are solved and VEMS is defitely suitable also for this kind of installation.
I would like to thak all those who have helped me with my project!!
Next update will arrive as soon as there's something to update...