9. Scanner / Logger, Laptop and AC inverter
Powertrain controllers are simply lookup tables or algorithm calculators-like any computer, they couldn't function (generate sensible outputs) without receiving operational data (input) from the sensors guiding them. Understanding how these inputs are used by the controller to generate the appropriate outputs is critical, yet often very complex. Scanners, which read and report sensor data (inputs) and operational commands (outputs like spark advance) in real-time, enable tuners to watch and learn how these inputs and outputs are interacting. The instantaneous sensor readings (inputs) at any moment can be used to locate the corresponding point in the tuning maps (output command source). The tuner thereby learns where in the maps to make the appropriate changes to the tune. Watching, comprehending, and remembering scanner readings becomes overwhelming very quickly. Loggers are used to record scanner data for future review. Typically, most scanners are capable of recording, or logging, as well. Some scan loggers operate as stand-alone tools, yet most offer PC interface. The most practical interface is with a laptop computer. Laptops are the computer of choice for most tuners, simply because of their ease of mobility. To keep them running indefinitely in a car, a power connection can be made with an AC inverter. Without the inverter, the laptop's battery-power can be disappointingly short-term, and the screens are typically too dim to view in daylight.
10. Real-time tuning or emulation
The one nice thing we remember about "old-school" tuning was that making changes caused immediate effects, all while an engine ran. There was no 'downtime' between tuning changes, unless it required hardware changes. With electronic powertrain controllers, applying changes generally requires some sort of reprogramming-and a shutdown of the engine to make the change. This guess (tune and reprogram while the engine is off) and test (restart and evaluate changes) type tuning does work, but may take dozens (or probably more, depending on complexity) of tries to perfect. 'Real-time' tuning allows making instantaneous changes while an engine runs.
If drilling holes and welding bungs in tubing is not your forte, there's still an effective way to utilize an AFR meter. We sketched out plans on a napkin for a simple clamp-on tube that can be slipped in a tailpipe and allows mounting the wideband sensor temporarily. Within fifteen minutes, our local fabrication guru Ken Estelle, buzzed one together for us in his home garage. | 
Contrary to popular belief, mounting thermocouples in pipes does not require welding. EGT offers both clamp-on type and weld-on type bungs for mounting probes. The clamp-on mount can be used anywhere a hole can be drilled and the clamp will fit. For the more permanent mount, weld-on bungs can be buzzed to the desired locations. |
Entry-level performance meters can be a good starting point for quantifying dynamic performance. This Gtech Pro meter was found on eBay for $49.95. More sophisticated (and better accuracy) meters can be found as well, depending one one's budget and needs. | |