Many times not all graphics are stored by the WaybackMachine, so if there are graphics missing from the following VFAQ, please don't email me about them (unless you are emailing me to tell me you have a copy of the missing graphic you can send me).

If you know the original author of this VFAQ, and have their contact info, please have them email me if they have any missing info to add, have the VFAQ at another site I could not find, or wish to have it removed from my site.

APEXi ITC Installation on 2G

BACKGROUND:

Equally as important as being able to control the air-fuel ratio when tuning a car for peak performance, is being able to control the ignition spark timing curve. The APEXi Ignition Timing Converter (ITC) is a new product that allows the user to set the spark curve to +/- 15 degrees at 5 different rpm points: 800, 2400, 4000, 5600, and 7200 rpm. The ITC unit draws a straight line between those points to complete the timing curve. Without an ITC to override the ECU's spark curve, the 2G ECU chooses one of five spark tables when the car is fully warmed up and running in wide open throttle mode. Depending upon coolant temperature, barometric pressure, airflow, cam angle, crank angle, throttle position, and rate of throttle position change, the ECU decides when the ignition spark is to fire relative to piston top dead center. The most conservative of these timing curves is not performance friendly and provides less than optimum power, to say the least. It is advantageous for the performance minded car owner to be able to add a few degrees of timing to the conservatively set factory programming, to maximize the power potential of the vehicle. Keep in mind that overriding the factory set timing curve can be dangerous to the engine if not done in moderation. Do not be terribly concerned though, because the safety provided by the engine knock sensor is not disabled by installation of an ITC. In the case of extreme engine knock, the ECU will still have the capability of pulling the timing way back to prevent or to minimize the chances of engine damage. Be aware that in most circumstances, though, fuel having a higher octane rating is required when running the car with more timing advance. So if you intend to advance the timing by 3 to 5 degrees, don't scrimp on fuel -- always use the highest octane pump gas you can find for street use, and always use race gas at the drag strip.

PROCEDURE:

White wire on ITC = crank angle output from ITC to ECU

Yellow wire on ITC = cam angle output from ITC to ECU

Green wire on ITC = cam angle input from cam sensor to ITC

Pink wire on ITC = crank angle input from crank sensor to ITC

Black wire on ITC = ground (must be the same ground that is used to ground the ECU to the car)

Red wire on ITC = main power to the ITC unit

The blue wire, the light blue wire, the brown wire, and the orange wire are not used in DSM installations. They should be insulated.

1. Disconnect the car's negative battery cable.

2. Remove the access panel from the driver's side of the center console (one steel screw and one plastic screw).

3. Maneuver your head under the steering column so that your left ear is pointing to the floor and your eyes are looking at the ECU box (which is inside the console). The following steps assume that you are positioned in this way, for ease of explanation.

4. You'll see that there are four plastic connectors which attach many wires to the ECU.

5. The left most connector has 26 terminals, the next from the left has 16 terminals, the next has 12 terminals, and the furthest connector to the right has 22 terminals. You should also look at page 24 of your ITC installation manual, if you have one -- Mitsubishi 4-connector ECU. The drawing states that it's for a 1996 and later model Lancer EVO IV, but that's the correct one for a 2G turbo DSM as well.

6. The terminals are numbered as follows (don't look for these numbers in your car, they're not there, these numbers are obtained via review of a 2G DSM shop manual):

On the far left connector, top row is 1 through 13 and bottom row is 14 through 26.

On the second connector from the left, top row is 31-38 and bottom row is 39-46.

On the third connector from the left, top row is 51-56 and bottom row is 57-62.

On the far right connector, top row is 71-81 and bottom row is 82-92.

Connector 1

Connector 2

Connector 3

Connector 4

7. Cut the wire at terminal 89 in half (terminal 89 is the crank angle sensor return signal to the ECU). Attach the lower end of the cut to the pink ITC wire. Connect the upper end of the cut to the white ITC wire.

8. Cut the wire at terminal 88 in half (terminal 88 is the cam angle sensor return signal to the ECU). Attach the lower end of the cut to the green ITC wire. Connect the upper end of the cut to the yellow ITC wire.

9. Tee the red wire from the ITC onto the wire at either terminal 12 or 25 (power supply wires for the ECU).

10. Tee the black wire from the ITC onto the wire at either terminal 13 or 92 (ECU ground wires).

11. Set the CAR SELECT setting on the ITC unit to D.

12. Set the 8 dip switches on the ITC unit to the following: up, up, down, down, up, down, down, up

13. Ensure all connections are tightly made up and are well insulated.

14. Connect the ITC wiring harness to the ITC unit.

15. Re-install the access panel on the center console.

16. Re-attach the car's negative battery cable.

17. Set all 5 control knobs on the ITC unit to zero timing adjustment (straight up).

Done. Now you're ready to start up the car and adjust the ignition spark timing curve to your liking. Where should the knobs be set for safe, high power operation? Well, that is up to you. I do not wish to tell you how to set your timing except that it may be unwise to set it at any greater than +5 degrees above stock at high rpm. I currently run the following spark curve as read on the ITC knobs (as directed by a very highly respected and accomplished 2G DSM owner who runs a DSM parts business and performance shop).

800 rpm: 0 (no adjustment)

2400 rpm: +5 degrees

4000 rpm: +9 degrees

5600 rpm: +5 degrees

7200 rpm: +5 degrees