4
Part #170450
Revised 3/08/07
FAST™
3400 Democrat Rd.
Memphis, TN 38118
Phone: (901) 260-3278 Fax: (901) 375-3408
www.fuelairspark.com
2.
To review the data log in real-time play back, simply press the down-arrow button (the button
next to the P on the display screen) (Fig. A). The log will load, the P will begin flashing, and
the data log will immediately begin its play back. At any time you can pause the playback by
pressing the down arrow (P) button. By pressing it again, you will resume playback from the
point you originally paused it at. When the log is finished playing, it will prompt you to decide
if you want to replay again. If you select no, you will be put back into the live air/fuel screen.
If you select yes, it will reload the log and begin playback again.
Advanced Options
:
•
Fuel Type:
Gasoline and alcohol (i.e. methanol) fuel calibrations can be selected, depending
on the type of fuel you chose to run. Once this is selected, it will become the default value
when the unit is powered up. You can go back later and change the fuel type at any time.
•
Analog Output Mode
: When reading air/fuel in this mode, an additional analog signal output
is provided that will run most external, electronic air/fuel gauges and/or feed an external data
logger (Fig. B). This signal is sent via two wires that are factory contained under the connector
heat-shrink wrap at the display housing end of the wiring harness (Fig. B). Simply cut the
shrink wrap back and pull out the black and grey wires. The black wire is the signal ground
wire and the grey wire is the analog signal output wire.
•
Simple Mode
: This takes the output voltage and multiplies it by 10 to calculate the actual
air/fuel ratio. Many external electronic air/fuel gauges use this signal type.
•
High Res Mode
: This provides a 0 - 4.096 volt output signal. Certain digital gauges and data
acquisition systems use this type of signal.
•
Narrow Band Simulator Mode
: This provides a narrow band output signal that simulates
many OEM style air/fuel sensors. This will allow you to use the wide-band style sensor the
FAST™ Air/Fuel Meter uses not only to serve the air/fuel meter, but to also run the engine’s
computer. This mode is compatible only with pre-OBDII vehicles.
Tuning Advice
Air/fuel ratio requirements vary greatly from application to application, but some generalities can be
found to get a tuner “in-the-ballpark” when tuning an engine. Below is a graphical chart that represents
the normal operating environment for most engines using gasoline for fuel. The left side vertical
column reads boost pressure or vacuum in the engine’s manifold. The horizontal bottom row is the
engine’s rpm. For those running methanol, the proper air fuel ratio changes dramatically. At part
throttle cruising and idle, the proper air/fuel ratio is around 6.4 to 1. At wide open throttle, an air/fuel
ratio of 5.5 to 1 is a good starting point for maximum power production.
