Back in "the old days" (2002-2003), the process for tuning a C5 was considerably more intricate than it currently is. At that time, you had to use one program to log and analyze data, and another to reflash the PCM with a new calibration. Tuning was a relatively tedious process because the two programs didn't "talk" to each other. Consequently, you found yourself continually switching back and forth between programs to determine the changes that had to be made. To make matters even more challenging, none of the programs available at the time were particularly user friendly.

Then I came across a scanning/data logging software package called EFILive. It was not only easy to use and to customize, it offered a number of unique capabilities, including a control panel that allowed the user to temporarily alter ignition timing, air/fuel ratio, and torque converter clutch lock/unlock settings-while the engine was running-with a laptop computer.

I hadn't used EFILive for very long before thinking, I wish these guys would develop tuning software. In early 2005, my wish was granted when the EFILive team of Paul Blackmore and Ross Myers released FlashScan, version 7.2. They followed that up with version 7.3 and have continued to add features to it, including the capability to scan and tune LS2/LS7, GM diesel, and four-, five-, and six-cylinder GM engines. Recently, they released version 7.4, which provides even greater scanning and tuning capabilities, and can be used with an even wider selection of General Motors ECMs and PCMs.

A fully integrated software package, FlashScan includes separate scanning and tuning programs, which operate independently but also interface with each other. This extremely well-done interface, which can be easily altered to accommodate individual user preferences, tremendously simplifies the task of implementing tuning changes based on data logged during testing.

To make tuning even more interesting, in late 2006, EFILive released its V2 interface cable that will ultimately allow stand-alone scanning and tuning (without requiring a laptop computer). The V2 cable also accepts data from up to eight external inputs, such as a wide band O2 sensor, thermocouple, or a variety of temperature or pressure sensors, or any analog sensor with a 0-5 volt output.

All LS1/LS2/LS6/LS7 tuning software does pretty much the same thing-it allows you to make changes to a vehicle's calibration data and write that data to the PCM.

What makes one program superior to another is ease of use, documentation, and the extent of changes that can be made to an existing calibration. In these areas, FlashScan is in a league by itself. No other data logging/programming package offers access to over 650 calibration parameters and tables combined with data monitoring and logging capabilities, the ability to link logged data with relevant calibration tables, and a control panel to make temporary changes on the fly.

Although electronic powertrain controls are often regarded as having almost magical capabilities, they simply offer more extensive and precise control of engine and transmission calibrations than nonelectronic mechanisms. Tuning, therefore, is as much a matter of learning to "control the controls," as it is a matter of developing the data that will enable the engine and transmission to deliver optimum performance. With FlashScan providing access to so many control parameters, it's relatively easy to gain control of virtually any aspect of powertrain operation. FlashScan also facilitates the development of the precise calibrations that are required to achieve specific results-such as establishing the fuel, spark, and air flow settings that enable an engine with a radical camshaft to idle as smoothly as possible.