by FordMuscle
Staff
Introduction
If you're running a carbureted Ford and you haven't seriously
considered
any of the Air Fuel measuring devices found in the www.fordmuscle.com
tech department archive, we know why. Air Fuel meters appear
too complicated, require too much software, provide too much
information, and cost too much money. Unfortunately, these
barriers prevent many traditional Ford enthusiasts from using
this tool to confirm they're running the right jets, power
valve, and have their idle mixture screws out the optimum
number of turns.
Air Fuel meters have long been a device
used by tuners who are mostly
younger and more "techy" than old school Ford hobbyists
like most of us. Since a great portion of the tuner crowd
rarely gets beyond cold air intakes, performance chips, and
exhaust systems, "data logging and laptopping" with
robust Air Fuel meters and bundled software offers them a
way to personalize their motors much the way we do with camshaft
selection. While we are not here to say which group produces
more legitimate hot rodders, we are here to say that if you
are not using the basic functionality of an Air Fuel meter
to tune your carburetor then you're probably pissing in the
wind everytime you pick up that long skinny flathead screwdriver.
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Innovate Motorsports DB Gauge
This compact Wide Band Air Fuel gauge kit from Innovate
Motorsports includes the basics for capturing Air
Fuel data. The controller is built right into the cable.
While the kit includes data logging software in addition
to the 02 sensor and gauge, the cost and simple install
make it perfect for simple "live" data tuning.
Retails for $289.00. |
Air Fuel Meters Dumbed Down
The key to eliminating your hesitation about purchasing, installing,
and using an Air Fuel meter on your carbureted Ford starts
with looking past manufacturer emphasis on data logging and
all the boring software screen shots found
in their marketing materials. Many of the most powerful Air
Fuel meters on the market use handheld or nontraditional displays
since a tuner's tuning decisions are expected to be made from
LOGGED data via a laptop computer. As the Air Fuel Meter market
evolves, a few manufacturer's have recognized that not all
enthusiasts are terribly concerned about or have the time
to study logged Air Fuel data. This is especially true for
carbureted street machines who's owners just want to be sure
their naturally aspirated motor isn't running too lean or
too rich without going to the dyno. In reality, all a traditional
street enthusiast needs from their Air Fuel meter is the ability
to:
Accurately
measure Air Fuel Ratio
Display
the "real-time" Air Fuel Ratio
Easily
mount the Air Fuel Ratio gauge
The Innovate Motorsports dB Gauge pictured above right is
a nice compact unit that fits these basic requirements at
a reasonable price. Take note that there is no control box
since the brain is built right into the cable.
Live Data Tuning with the ACCEL
DFI
The ACCEL
DFI Wide Band 02 Kit is a perfect example of a data logging
device who's manufacturer understands the need for a mountable
gauge even with their most capable Air Fuel meter. While this
unit offers more configurable features than most carbed enthusiasts
will ever need, the digital gauge does allow you to start
tuning immediately from live data (via gauge feedback). For
most, this may be the only way they ever use an Air Fuel meter.
However, the benefit of a high-end unit like this one is that
once you get comfortable live tuning, you then have the option
of analyzing 15 channels of logged data with the included
DataMap software and ACCEL's Gen 7 logging feature. Another
unique feature of the ACCEL DFI Wide Band 02 Kit is its ability
to trigger external devices based on RPM, vehicle speed, and
Air Fuel Ratio. For now however, let us show you how we got
the 650cfm Holley atop our Torino's 351C dialed in with just
live data from the ACCEL DFI Wide Band 02 kit.
After installing the ACCEL unit
on the Torino, the first step was to determine target baseline
Air Fuel Ratios for idle, cruise, and wide open throttle.
The following table was pulled
from the ACCEL DFI instruction booklet. The table is by no
means an absolute reference for the perfect Air Fuel Ratio
for all applications. However, the information provided serves
as a great baseline for experimenting to see how idle mixture,
primary jet, power valve, and secondary jet adjustments impact
power, economy, and drivability. The row highlighted in tan
best represented our 351 Cleveland's profile and most street
performance Ford V8's. With the chart as a guideline we focused
on the first and easiest carb adjustment. What else but idle
mixture?
Recommended
Baseline Air Fuel Ratio Chart
(per ACCEL DFI)
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Engine Type
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Idle
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Cruise
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WOT
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Stock - little or no modification
to engine, 87 octane gasoline
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14.7:1
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14.7:1
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12.5:1
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Street/Strip engine - naturally aspirated,
performance camshaft and exhaust, 10.0 - 11.0 compression,
premium pump gasoline
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14.2:1
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14.0:1
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12.8:1
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Race Engine - naturally aspirated,
high lift/duration cam, 12:1 or higher compression,
high flow heads and exhaust, high octane race fuel
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13.5:1
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13.5:1
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13.0:1
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