Electronic tuners work in conjunction with your electronic control unit (ECU) to adjust different electronic procedures in your vehicle, including its throttle response or fuel-to-air ratio. Tuning a vehicle will affect many different components, including throttle position, ignition timing, ignition spark, and fuel injection.
Tuning your throttle response involves working with what’s called a throttle map. This is essentially a computer code that monitors different variables of your throttle response, including throttle position and engine load. In layman's terms this is most often used to adjust throttle position, or how much your throttle butterfly must open and close depending on acceleration. This will also affect the fuel-to-air ratio of your intake.
Many modern vehicles now employ a “drive by wire” system that can transmit signals from a variety of sensors to actively monitor and adjust throttle position on a feedback loop. These are considered much more efficient than older cable systems and simpler from a mechanical perspective.
Essentially, “drive by wire” systems replaced existing cabling between the throttle and throttle pedal with electronic wiring. This gave drives more control over throttle tuning and, in turn, more control over torque delivery.
There are two types of tuners we should concern ourselves with. The first is a throttle response tuner, which only regulates throttle response. The other is a handheld tuner that allows you to adjust other variables, such as spark advancement.
Throttle response tuners are convenient because they allow for quick plug-and-play access, and they’re cheaper. Tuning devices are more complex, and require manual adjustment through its interface by either yourself or a professional.
Handheld tuners offer more sophistication and diagnostic control. While a little pricey, enthusiasts generally invest in handheld tuners to improve their torque and horsepower.