by Chirag Asaravala
With wideband oxygen sensor pricing having dropped significantly
over the last several years, consumer digital air-fuel meters
are more affordable then ever before. For under $500 you can
own the same tuning capability that before could only be rented
during a dyno session.
It seems so simple that one might wonder if there are any
downsides to these devices. The answer is yes. Just about
all of the air-fuel meters on the market still lack refinement.
They fit in that category of "techy" tuning products,
looking like Radio Shack projects boxes with clumsy switches
and requiring a laptop to configure. They work well if you
are willing to put in the time, but the normal enthusiast
would quickly lose interest and
go back to tuning by SOTP (seat of the pants.) Besides, we'd rather
be out tuning the car than behind a laptop tuning the tuning
The FAST air-fuel meter has the capability of running
single or dual wide-band oxygen sensors. Shown is the
dual-sensor kit, PN:17402, which costs about $460.
We recently were presented with a Fuel
Air Spark Technologies (FAST) new wideband meter to test.
While the unit is marketed for its dual oxygen sensor capability
- enabling the separate, or averaged, air-fuel ratio (AFR) reading
of both exhaust banks, we were impressed by its design and self-contained
operation. There is no need for a PC to get this unit configured.
For carbureted engines this is a slam-dunk. Install a couple
of oxygen sensor bungs right after the headers and you're on
your way to precision tuning your idle, part throttle, and wide
open throttle fuel delivery.
However, on an EFI car the appeal of dual-bank AF ratios is
immediately soured by the thought of wiring up two more sensors
into the exhaust. FAST however has solved this issue. The unit
is capable of delivering an analog signal that can be set to
simulate a narrowband 0-1V signal. You can have a wideband air-fuel
meter which will simultaneously replace your stock narrow-band
sensors. Read on, we'll show you how.