Apexi S-AFC

Here is my (hopefully simple) version of Apexi S-AFC (second generation/blue screen version) installation for a 3/S. It was installed with stock fuel injectors, and all values were kept at 0% for now, until larger 450cc/min DSM injectors can be installed.

Go to the Apexi Website and use these reference documents for diagrams:

Remove carpeted panel on driver side of center console. The ECU is mounted vertically behind the radio with the wiring harnesses facing the driver side.

Splice or solder the wires to the ECU wiring harness according to the references above, or use the table below and Stealth 316 ECU Info Page, as reference:

AFC Wire	ECU wire	1G ECU Pin #	2G ECU Pin #	3G ECU Pin #
red	power	25	25	47
green	RPM signal	101	58	45
brown	ground (closer to ECU)*	26	26	58/51
black	ground (farther from ECU)*	26	26	58
orange	air flow signal input(to AFC)**	70	90	61
pink	air flow signal output(from AFC, to ECU)**	70	90	61
grey	throttle signal	64	84	78
blue	unused (air flow signal input #1 for hot-wire, flap, or pressure sensor)	--	--	--
white	unused (air flow signal input #2 for hot-wire, flap, or pressures sensor with twin air flow)	--	--	--
yellow	unused (air flow signal output for hot-wire, flap or pressure sensor)	--	--	--
*brown wire must be connected closer to the ECU than the black wire
**completely cut air flow signal wire with orange wire as input to AFC and pink wire as output from AFC to ECU

Turn the ignition on, but don't attempt to start the car.

From main menu go to "etc." The setting for "Sensor Type" is "Karman". The settings for "Car Select" are"6" for "Cyl" and the "up arrow" for "Thr".
There are more things to use from the etc menu, but none are critical. As one additional note on the "dec.-air" function: contrary to what most people think, I don't think that the afc will help running rich between shifts. most people claim that the "dec.-air" function will do it, but from the afc manual:
"Some vehicles equipped with hot-wire air flow meters with forced induction units and may experience engine stalling when the throttle is let off. This can be caused by a blow off valve releasing into the atmosphere, lack of a blow off valve, or the use of a very large turbocharger. By using the Dec.-Air function, the unit can prevent the tendencies for engine stall."
3/s cars have a karman type sensor (not a hot-wire air flow meter), so I'm assuming the the function does not do anything. Many people claim that it can be used to solve the fairly common problem of running rich between shifts and/or stalling, but I know of no one that has successfully done it, and gotten positive results.

To take advantage of the many different ways of using the monitor functions, read the full "S-AFC Manual". For the monitor settings, there are six available options, however only four are applicable for 3/s cars:

Afl - not applicable (air flow usage % - for hot wire/flap type MAF)
Prs - not applicable (intake manifold pressure)
Kar - air flow signal in Hz
Thr - throttle % (0% to 100%)
Rev - engine rpm
Cor - correction % (-50% to 50%)

To set the correction percentages, from the main menu, go to "setting", and adjust the correction percentages at each RPM. For a car with stock injectors (360cc/min), set all correction percentages to 0% as a baseline. I highly recommend leaving the stock injectors installed when installing the AFC to make it significantly easier to diagnose problems.
Start the car, and make sure it idles well. If it won't start or idles poorly, check all electrical connections, then check all settings, and finally check all intake hoses for leaks.

I chose to mount the AFC to the center vents with the supplied bracket. I slid the bracket under the vents with a bit of pressure, and it holds in place very well.

I also chose to route the wires through a small gap just above the carpeted panel on the passenger side of the center console. It will probably require removal of the panel to get the wires through the gap.

When all is working well, reinstall the center console panels. For my AFC settings with 450cc/min DSM injectors, see my Fuel Injector Installation Page for baseline correction percentages.

Use all information in this guide, including descriptions for wires and settings, only as a reference, and at your own risk.

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