1988 VW Polo mk2 16V turbo Digifant I


16VT’s involvement: Modified the customer supplied Megasquirt v3 MS2, and supplied a fully functional plug and play G60 loom for a customer in Germany; calibrated fuel, ignition and idle on a local vehicle with similar hardware before shipping out the loom+ECU.

Chassis: stock;

Forced induction: GT28RS.

Engine: 1800cc, KR engine code, 16 valve, Audi 20V intake manifold.

Injection: Port injection, 245cc/min  highZ injectors, Bosch coolant and Bosch intake temp sensors.

Description:  The objective was to replace the  Digifant 1 system with the megasquirt. A suitable adapter was made to link the megasquirt to the digifant 1 loom. All stock sensors were used. A V3.0 Megasquirt PCB was used.

Pin configuration:

MS GROUNDS (8,9,10,11) go to T25/13, T25/19 (black)
MS SENSOR GROUND (19) goes to T25/6 (black)
MS MAT (20) goes to T25/9 (red/black)
MS CLT (21) goes to T25/10 (yellow)
MS TPS SIGNAL (22) goes to T25/15 (blue)
goes to T25/2 (blue)
MS PIN 24 goes to T25/8 (hall sensor 12V supply via jumper from T25/14) (red)
MS PIN 6 goes to T25/18 (hall sensor signal to 4N25 via XG1) (green)
MS TPS Vref (26) goes to T25/11 (white)
MS +12V (28 ) goes to T25/14 (red)
MS FIDLE (30) goes to T25/22 (yellow)
MS INJ1 (32,33) goes to T25/12 (green)
MS INJ2 (34,35) wired externally (yellow)
MS IGN (36, using D14 output) goes to T25/25 (brown)
MS FUEL PUMP (37) goes to T25/3 (green)

Options included:

Launch control on pin 3 (red wire) using JP4 (XIRQ in megatune)
Output 1A (PT6 in megatune) on pin 4 (white) using ZTX450 (rated at 1000mA) and SPR2, currently set as 6000rpm shift light
Switchable maps on pin 5 (blue wire), not hooked up since MS2 1.0.2 does not support input switch
Pin 6 used for hall sensor signal
Pin 25 is freeeeeeeeeee
Pin 27 is freeeeeeeeee
O2 sensor (pin 23) Tee'ed off and brought out as yellow wire for use with LC-1
Output 2A (PT7 in megatune) on pin 31 (pink) using IAC2B and ZTX450, currently set to be grounded when MAT>50C