Once the tune is created and modified, it is transferred into the EEC V via the Predator, which is a handheld device that facilitates the uploading and downloading of tune-up programs. It's also capable of monitoring various engine functions, such as temperature and mass air voltage, while dyno testing a 'Stang. Custom tuning involves a lot of back-and-forth between the PC workstation and the vehicle on the dyno. So saddle up for a long day of trial and error-you'll quickly learn how valuable that time is when you start to see the performance improvements.
This new XD-1 air/fuel gauge from Innovate Motorsports (PN 3763; $299.99) proved to be an extremely valuable tool during our dyno tuning. We used the gauge in conjunction with Innovate's LM-1 air/fuel-ratio meter, but it also works with the LC-1 Lambda cable, a stand-alone wideband controller (PN 3769; $199.99) we saw at SEMA last year. Clear, digital, at-a-glance readings of the actual ratios-as they rose and fell-helped Saul determine which way to go with the tune. This 14.7:1 reading represents the stoichiometric air/fuel ratio, or the chemically exact amount of oxygen atoms necessary to completely burn fuel in an air/fuel mixture, under zero-load conditions at idle. Some tuners like to think of this as optimal fuel burn. When the reading on the gauge is higher, the air/fuel mixture is considered lean. A number less than stoichiometric denotes a rich mixture.
We're using Auto Meter's NV series 211/416-inch gauges to monitor boost (PN 7307; $70.00) and fuel (PN 7363; $200.00). The boost gauge is mechanical and gives us accurate readings of both vacuum and boost at the top of the rpm band. The fuel gauge is an electric, full-sweep unit that measures pressure up to 100 psi. This photo shows the "night-vision" green illumination of the gauges, which works well with the factory dash lighting. The NV's brightness is strong, so we recommend giving yourself some adjustability with Auto Meter's LED lighting dimmer (PN 9114; $30.00).
This is the spark-advance table Saul uses to help create our custom tune, as seen through DiabloSport's "Chipmaster Revolution" software. Saul starts with information in this table and, through incremental testing on the dyno, is able to modify our blown Mustang's spark timing to increase power while maintaining a safe buffer from detonation.
This is the DiabloSport open-loop fuel table. When the ECM is operating under open-loop conditions, the O2 sensor works in conjunction with this table, the mass air transfer file, and signals sent to the processor from other sensors-such as coolant temp and air-charge temp-to maintain the desired air/fuel ratio.
Since our 'Stang is now putting out street-credible power at the rear wheels (we set the bar at 350 hp and 350 lb-ft), we think it's worthy of wearing Performance Parts' new "4.6 Interceptor" badges (www.performancepartsinc.com; $8.99/each). The factory "GT" tags were removed from the fenders and rear panel, and these babies now let folks know the real deal.