Read this over and over until it makes 100% sense.
Then you are ready to start tuning with an SAFC

http://users.wpi.edu/~ktarry/dsmtech/tuning.html

 

I've never seen that before, then again, I haven't looked, lol.
Thanks for that link DSMTalonAWD51.

 

I'm going to add on to this DSMTalon...
[quote][quote name='BluFalcon' date='Nov 5 2006, 05:28 PM' post='3578']
Ran across this on GVR4.org while searching for something totally unrelated. Figured it might come in handy for some folks. I didn't write it, I just found it. If anything is wrong in here, please feel free to discuss. Thanks.
[b]Someone else wrote this FYI

Basic tuning theory

The factory Engine Control Unit (ECU) employs a narrowband Oxygen
sensor to check the results of a closed-loop fuel ratio control process.
The ECU
comes with fuel maps that are based on the input from several engine
sensors: The Intake Air Temperature sensor, Barometric Pressure sensor,
Engine Coolant Temperature sensor, and Knock/Detonation sensor. The details
could fill a large book, but the easiest way to think of it is that once the
engine is at a normal operating temperature, the Fuel Injectors are opened
for a certain amount of time, which is determined mainly from the Airflow
reading. DSMs use a Karman Vortex style of Mass Air Flow sensor (MAF) that
the
air filter assembly attaches to directly. It is important to note that the
airflow value is determined BEFORE the air is pressurized by the turbo,
and that any air leaks in the piping between the MAF and the throttle-body
will skew the airflow reading. A leak before the turbo will result in the
ECU
getting a smaller airflow reading than it should, and a leak after the turbo
will result in the ECU getting a larger airflow reading.
The ECU operates in two modes. The first mode referred to as "Closed-Loop"
is what the ECU uses for part throttle and cruising operation. In
closed-loop operation the ECU cycles the air fuel ratio between a little
rich and a little lean using the Oxygen Sensor Feedback Trim as shown on a
datalogger. In this mode the actual Oxygen Sensor Voltage is unimportant,
but the fact that it is cycling up and down is useful since it means the ECU
is operating in closed-loop properly, allowing the ECU to fine-tune the
Air/Fuel Ratio (AFR).
The second mode of operation is called "Open-Loop" and is used mainly
at full throttle or whenever the engine RPM is over 4500. The ECU also uses
Open-Loop if the fuel trims are out of range (I.E. you don't have it tuned
right). In this mode the ECU adds fuel based on a direct lookup of the
airflow on a fuel map. No fuel trims are used to adjust the base maps in
this mode. The oxygen sensor voltage output will be fairly constant in
this mode and can be used to determine whether the AFR is rich or lean. In
short, if the O2 voltage is cycling up and down several times a second
then it is in Closed-Loop, and if the O2 voltage is steady then it is in
Open-Loop.
The fuel trims are adjusted by the ECU automatically to provide the
"proper" AFR during all cruising/part throttle situations. This process
works very well and the stock ECU is able to compensate for most sensor
calibration problems. The ECU cannot compensate for larger injectors, or a
crazy big fuel pump, or a modified MAF, this is where the AFC becomes
useful.

---------------------------------

How the AFC Works

The AFC is a simple device that alters the airflow signal that the ECU
reads. The AFC sits between the airflow sensor (MAF) and the ECU, and
works similar to an EQ for a stereo. The AFC adjusts the airflow value that
the
ECU reads up, or down based on RPM, and switches between a LO and HI
adjustment map based on throttle position. On a DSM the MAF changes the
frequency of the output signal based on airflow, so the more airflow the
higher the frequency. The AFC takes the frequency input from the MAF,
looks at the engine RPM, then looks at what the setting is on the AFC for
that
RPM. Since the AFC has a limited number of RPM points, the AFC
interpolates the values when between two RPM points. So if the 4000 RPM
setting is +15% and the 5000 RPM setting is +12%, and the engine is running
at 4500 RPM then the AFC would adjust the frequency that the ECU sees by
averaging the two values. In this case it would be (15 + 12) / 2 = +13.5%.
There are two maps on the AFC. One is called the LO map and the other
the HI map. Which map it uses is determined by the throttle position.
When the AFC is initially set up, the throttle position for the LO and HI
map is configured. The default is something like 30/60. This means the LO
map values will be used exclusively from 0-30% throttle, then it will
interpolate values between the LO and HI maps from 31-59%, then use the
HI map exclusively from 60-100% throttle position. For a DSM application,
it is easier to tune if the maps are either on or off, instead of mixing
the values between them. Set the Th-Point to 69/70 so it uses the LO map up
to 69% throttle and then goes to full HI map beyond that. This separates
the
maps into closed loop and open loop maps, making it easier to tune.

--------------------------------

Initial AFC Setup

A few installation tips first. Be sure to use the Pink and Orange wires
for the airflow signal wires, and NOT the Yellow and White wires. The AFC
is
a universal device and is setup to handle both Speed-Density and
Mass-Airflow type systems. The Pink and Orange wires are for Mass-Airflow
systems like DSMs.
In the Setting Menu, set the Th-Point to 69 for Lo and 70 for Hi. Set
the Ne-Point so the RPM points are 1000, 2000, 3000, 4000, 4500, 5000,
6000, 7000 for stock rev limiter, or 1000, 2000, 3000, 4000, 5000, 6000,
7000,
8000 for raised rev limiter.
In the Etc Menu, set the Sensor Type to "Karman" for a DSM. The Car
Select should be set to Cyl 4 with the Thr arrow pointing up meaning a
rising rate throttle position sensor. Set the GRPH Scale to 30,
Initialize will reset everything to factory defaults so it should be set to
No.

------------------------------------------------

Usage Tips provided by Road Race Engineering:

1. Monitor
For monitoring gauge functions, we like the following settings:
1 Gauge RPM
2 Gauges RPM and Karman
3 Gauges RPM, Karman and Correction
4 Gauges RPM, Karman, Correction and Throttle Position
You will not be able to see any values for "Air Flow" or "Pressure". Why?
Because you don't have an air flow meter or a pressure sensor to monitor.
These are for other cars.
If you push briefly both "Prev." and "Next" at the same time, you jump
from which ever screen that you are on in Monitor to the last screen you
were
in on Setting. It allows you to jump directly from monitoring throttle
position and RPM directly to the Lo-thrtl setting menu for adjustment.
When on the Lo-thrtl menu, push "Next" to jump to Hi-thrtl. By pushing
"Next" you can jump back and forth between Hi and Lo.

2. "Blue Wire Mod"
Huh? Blue wire mod? This allows you to read Oxygen Sensor Voltage on the
AFC display. On the wire harness for the AFC there are three wires that
normally not used on an Eclipse. These are White, Yellow and Blue. The Blue
wire is meant for the second Air Flow Meter on a Nissan 300ZX. You will
connect this wire to the O2 sensor wire right at the ECU. See the Jumptronix
Install instructions for info on where to get the O2 sensor signal. To read
the O2 sensor voltage, scroll down to and select the "etc." menu. Select
the "Sensor Check". Of the three readings, O2 voltage will be the middle one
(#2)

3. Common Problems:

-RPM Signal off by half (1G)
Because of the way that Mitsubishi triggers the ignition coils, this is
normal. To fix it, just set the Cylinders to "2"

-Car runs like crap, wont rev past 2-3K rpm, No change in the Hz reading
on the Karman display
You read the wrong section in the manual and chose the yellow and white
wires to modify the airflow signal. Wrong, you should have used the pink
and orange w