1994 VW Golf VR6
turbo
16VT’s involvement: Supplied
a plug and play Megasquirt
ECU to control idle, fuel and ignition, with preloaded base maps for a
customer in UAE;
Chassis: stock;
Forced induction: Holset HX40, Audi external wastegate with stock spring,
EIP-style split-pulse exhaust manifold, aftermarket 2.5" FMIC,
3” downpipe,
60mm intercooler piping, HKS EBC, HKS blow off valve, 1.0+ bar of boost.
Engine: 2792cc, AAA engine
code, 12 valve, free-flow filter & exhaust, C2 spacer to
lower CR to 8.5
Injection: Port
injection, ~200cc/min stock HighZ
injectors, Motronic
ECU, 60-2 trigger wheel, variable reluctance crank
sensor, PWM 2-wire bosch
idle valve, Bosch coolant
and GM intake temp sensors, coilpack
with integrated
module driving 3 coils in wastespark
mode
Description: The
objective of this install was to use the original wiring loom. To do
this, an
old 68 pin ECU was cannibalised and turned into an adapter. The MS was
installed inside the car, with wires running to the 'ECU' box. All the
original
sensors and actuators were used. Shielded wires were used for the VR
sensor.
MS
v3 internal mods
included using the CPU outputs directly to drive the VAG
ignition module (+5V to
trigger
coil), with a 330ohm resistor placed inline to limit current drawn from
CPU. A
TIP122 was installed to PWM control the 4 ohm idle stability valve.
Standard GM 2.49k bias
resistors were used. C31 was reduced from 0.1uF to 0.001uF to cure VR sensor phase shift.
To
make the install compatible
with the VAG relays, the following was done:
Pin configuration:
MS GROUNDS (8,9,10,11)
go to T68/1, T68/7, T68/55, T68/56, T68/58
MS
SENSOR GROUND (19) goes to
T68/33
MS
MAT (20) goes to T68/36
MS
CLT (21) goes to T68/14
MS
TPS SIGNAL (22) goes to T68/40
MS
O2 SENSOR SIGNAL (23) goes to
T68/20
MS
TACH IN aka VR+ (24) goes to
T68/67
MS
VR- (7) goes to T68/68
MS
TPS Vref
(26) goes to T68/41
MS
coil A
(36) goes to T68/8
MS
coil B (25) goes to T68/52
MS
coil C (27) goes to T68/60
MS
+12V (28 )
goes to T68/23 through 5A fuse
MS
FIDLE (30) goes to T68/53
MS
INJ1 (32,33)
goes to T68/2, T68/4 and T68/25
MS
INJ2 (34,35)
goes to T68/3, T68/24 and T68/26
MS
FUEL PUMP (37) goes to T68/6
Options included:
MS
LAUNCH CONTROL on DB37 - pin 3, JS11 - SPR1 (yellow wire)
MS
Output 1 on DB37 - pin 4, JS2 - SPR2, ZTX450 transistor (green wire)
MS
Tacho
out DB37 - pin 29 was fed to T68/22 to drive cluster, IAC2A - JS0
MS
SWITCHABLE MAPS on DB37 - pin 31, IAC2B (blue wire)
Crank signal was decoded using MSnS-E HRcode 09a. 60-2 wheel, with 14th (15th if 0 and 1 are the missing teeth) tooth at TDC. Trigger angle 60*. Trigger position A was 5, Trig pos B 25, Trig pos C 45, Trig return pos A 14, Trig return pos B 34, Trig return pos C 54. Spark output was INVERTED since the VW module goes from 0 to 5V when it wants to trigger the coil. Using 3ms on the MS for now.