If you've spent any time around drag racing, you've probably heard the term "auto shifter" thrown around. But what exactly is it, how does it work, and is it worth adding to your bike? Here's everything you need to know.
What is an Auto Shifter?
An auto shifter (also called a quick shifter or air shifter) is a system that allows you to shift gears at full throttle without using the clutch. Instead of rolling off the throttle, pulling the clutch lever, and shifting — which takes time and breaks your acceleration — an auto shifter lets you bang through gears seamlessly while staying pinned.
There are two main types:
- Air shifters — use a small pneumatic cylinder (powered by a CO2 or nitrogen tank) to physically move the shift lever. Common on dedicated drag bikes.
- Electronic quick shifters — use a sensor on the shift lever to detect shift pressure and momentarily cut ignition or fuel to unload the transmission, allowing a clutch-less up-shift. Common on street and track bikes.
How Does It Work with a Shift Light?
This is where it gets interesting for Raptor Performance customers. Our shift lights with the optional auxiliary output can automatically trigger an auto shift system at your programmed shift RPM. Here's the sequence:
- You accelerate and the engine climbs toward your shift RPM
- The Raptor shift light LEDs activate to warn you to shift while simultaneously activating the auxiliary output that sends a ground signal to trigger your ignition kill (like the Raptor Soft Kill)
- The brief ignition cut unloads the transmission, the shift happens, and you're already accelerating in the next gear (usually in under 50 milli seconds (0.050 seconds).
The result is faster, more consistent shifts with zero throttle lift — exactly what you need to cut elapsed times on the drag strip.
What is a Soft Kill?
A soft kill is a type of ignition interrupt that briefly cuts ignition to one or more cylinders to unload the drivetrain during a shift. Unlike a "hard kill" that cuts all ignition completely, a soft kill is gentler and more controlled — reducing the chance of a missed shift or drivetrain shock. The Raptor Soft Kill module is designed specifically to work with our shift lights for smooth, clutchless upshifts on sport motorcycles.
Do You Need an Auto Shifter?
- Street riding or occasional track days — probably not necessary. A shift light alone will help you shift at the right RPM consistently, which is the bigger gain for most riders.
- Bracket racing or ET-focused drag racing — yes, absolutely. Eliminating clutch time and throttle lift between gears can shave real tenths off your elapsed time, and the consistency of an auto shift system makes your runs more repeatable.
- Top speed or heads-up racing — yes. Every millisecond counts, and clutchless full-throttle shifts keep your acceleration curve as smooth as possible.
What You Need to Get Started
To run an auto shift setup with a Raptor Performance shift light, you'll need:
- A Raptor shift light with auxiliary output (single or dual mode) — this provides the trigger signal at your shift RPM
- A Raptor Soft Kill module — receives the trigger signal and performs the ignition cut
- An air shifter — to move the shift lever automatically rather than manually pushing it
All of these components are manufactured in-house at our Tennessee facility (except the air shifter which is available at many motorcycle speed shops) and are designed to work together seamlessly.