APEX Integration burst onto the scene a few years ago with the goal of introducing high-quality race-bred street parts at affordable prices. Since hitting the scene, the company has flexed its technological muscle in the arena of electronics. An example cutting edge of technology is the Super AFC Fuel Computer. In this third generation of upgrades, the AFC has gone digital. This means not only that the knobs have disappeared, replaced by soft-touch directional keys, but also that the incoming information and outgoing calculations happen millions of times faster. This faster processing speed translates into more accurate and precise control of fuel-related events, and, combined with diligent tuning, a faster and more reliable ride for the end user.
The APEXi S-AFC is housed in a silver case that is 1/2-DIN size. The display screen is relatively large, well-lit and easy to read-even under the most spirited driving conditions. Illuminated by an eclectic blue-green Vacuum Fluorescent Display (VFD), the the unit would complement any interior.
Our IS 300 tester's 1JZ-GE has been lightly modified with a high-flow intake and cat-back
Functioning as a meter display, the S-AFC does cartwheels around the competition. Three modes of display can be shown on the screen: "Numerical," with it's real-time adjusting numerals; "Analog," which imitates two small gauge faces with needles; and "Graph," a running bar graph of under-the-hood events. Using any of these modes, the user can actively monitor intake manifold vacuum, intake manifold pressure, air flow capacity, engine rpm, throttle position or airflow correction percentage factor. All of this information is pertinent to the driver that wants to know his engine, not blow his engine.
At the heart of the S-AFC's magical powers is the ability to control fuel delivery at eight rpm points throughout the powerband, offset in increments of 500 rpm. This precision control allows the user to add (or subtract) fuel where needed. The advantage of an electronic fuel control system vs. a manual one (such as a high-pressure fuel pump or larger injectors) is that it allows for precision tuning where it's needed. In addition, the S-AFC can help tame the rough idling, poor fuel economy and erratic power delivery of engines with upgraded larger injectors and high-flow fuel pumps.
All of this is done electronically through the vehicle's factory airflow meter or MAP sensor. The S-AFC jumps in line at the vehicle's ECU, where it takes the reading coming from the ECU, recalculates it according to a percentage difference set by the tuner, and then sends it back to the ECU which tells the fuel system to compensate accordingly. It is a simple and logical technology, and we wanted to see how well it works.
We took an S-AFC to Nacho Negishi at Dynamic Autosports in Lake Forest, Calif. and set up a blind date between it and a slightly modified 2001 Lexus IS 300. The IS 300 is a "new classic" stateside, now that our market has finally been blessed with its own version of the Toyota Altezza "wnderkar." Nacho happily and easily conquered this first-time install as soon as he found the ECU, which was hidden in an air-cooled box in the engine bay. The S-AFC was very easy to install with the included car-specific wiring diagrams, including pin locations and a minimum amount of connections.
Finding the ECU is a bit tricky as Lexus has positioned it in a ventilated box in the engi
The box is cracked open to gain access to the ECU to splice in the S-AFC.
Installation requires tapping into a number of wires. Here our intended victim is this yel