KJ Jones Senior Technical Editor
December 1, 2008
The G-Tech/Pro EGS tachometer automatically recognizes the shift light as soon as it's plugged into the device. We dig the way the shift light's three yellow LEDs are sequentially activated at 500 rpm before a programmed shift point. How's that for a warning that it's almost time to grab the next gear?

We've stressed on several occasions the critical role an optimal air/fuel ratio plays in ensuring a 'Stang's engine is operating at its best performance levels. The wideband O2 sensor and gauge are tools to count on when testing various engine parts and tuning Mustangs on the chassis dyno; of course, a tachometer to monitor engine speed is the other device that factors into the tuning mix.

Tuning on the street is another story. Not that it's night-and-day different from using a dyno, as achieving optimal air/fuel, for good drivability as opposed to WOT, is the main objective when road testing, but when you're doing it all yourself, trying to drive, datalog, and manipulate tuning software simultaneously is all but impossible. Every so often, we use Tech Inspection to showcase data-related instruments and diagnostic equipment that we think are cool and can be helpful to Mustang enthusiasts who tune their Ponies themselves, as well as the Melvin types who fiend on interesting technology.

For 'Stangbangers with Ponies and other Fords that have on-board diagnostics (OBD-II) electronics, G-Tech now offers its Pro Expandable Gauge System, a cool setup that we think will satisfy the DIY tuners' needs as well as the general interests of the data geeks out there. The Pro EGS is built around a 4-inch, 1,000-10,000-rpm tachometer and can process and record ODB-II data and rpm directly from a 'Stang's ECU, as well as air/fuel details by way of its wideband O2 sensor. It presents the information through a built-in, graphic LCD display.

Check out the photos and captions of the EGS's simple installation while we highlight this cool datalogging system's key features.

The OBD-II and wideband modules are plugged into the EGS at two ports located in the lower-righthand corner of the unit's rear panel. The 12V power connection sits at the immediate left of those ports. Of course, the power harness includes power and ground wires (we elected to connect our power wires to a cigarette-lighter plug, which enables us to use the EGS in different Mustangs), as well as a green tach wire that can be used to establish an isolated source for engine-rpm data. The EGS also displays rpm output taken directly through the OBD-II module, which is connected to a data port located below the dash. It's important to note that the OBD-II rpm reading may not be 100 percent accurate at all times as the module is processing several elements of data while the engine is running.

Using on-board diagnostics (OBD-II in '96-and-later Mustangs) has lately become one of the more popular ways of getting vehicle information that isn't readily displayed in the instrument cluster. The EGS includes this OBD-II module, which works with all of the current OBD-II protocols-including the super-fast CAN protocol-and provides valuable information such as ignition timing, throttle position, intake pressure, water temperature, and more. The standard trouble codes are displayed in English (for example, "Cylinder No. 6 Misfire"), and you can even clear trouble codes yourself. The device's smog-check feature is a huge plus for California-registered 'Stangs. Using OBD-II's emissions data, the system performs calculations that can determine whether or not a Pony is ready for its smog check.