Kartboy

About Kartboy: 25+ Years of American-Made Subaru Performance

Kartboy is one of the most respected names in the Subaru aftermarket — and for good reason. The brand was born in a San Diego machine shop in 1999 when Tom Deadrick, frustrated by vague shifts and weak stock components, started making his own parts for his Subaru. What began as a passion project quickly became a cult favorite among Subaru enthusiasts, with every part designed, machined, and tested in-house. More than two decades later, the Kartboy name remains synonymous with precision and reliability in the Subaru community.

Racing DNA, Street-Proven Results

Tom Deadrick, better known as "Kartboy," is an aerospace fabricator by trade with deep roots in high-performance motorsport, bringing advanced composite and metal fabrication skills to the world of Subaru tuning, backed by hands-on experience in CART, NHRA, SCCA, IMSA, and 125cc shifter kart competition. That motorsport pedigree is evident in every component the brand produces — from the tight tolerances of its transfer case control levers and short shifters to the durability of its suspension hardware.

All Kartboy hardware — from short-throw shifter assemblies to shifter bushings, differential wedges, sway-bar endlinks, and oil caps — is designed, CNC-machined, anodized, and assembled in the USA. That commitment to domestic manufacturing means tighter quality control and parts that are built to last the life of the vehicle.

Signature Short Shifters & Drivetrain Upgrades

Kartboy's drivetrain lineup includes short throw shifters, front and rear shifter bushings, and complete combo kits, all engineered to deliver tighter, faster, more confident gear changes. These setups include a CNC-machined short shifter that reduces throw by up to 40%, along with front and rear bushings made from high-durometer polyurethane to tighten up both front-to-back and side-to-side movement. It's little wonder that Kartboy's short shifter combo is widely regarded as one of the best bang-for-buck modifications available for the WRX and STI platforms.

Rounding out the drivetrain experience, Kartboy also offers a selection of manual transmission shift knobs designed to complement the feel of their short shifters and give drivers a more tactile, connected interface with the gearbox.

Suspension & Chassis Hardware

Kartboy provides a range of suspension and chassis upgrades including endlinks, sway bar bushings, and subframe bushings, engineered to stiffen key areas of the chassis, reducing unwanted movement and improving responsiveness during cornering. Upgrading these components helps maintain alignment settings and extends the life of the suspension. The brand's sway bar adapter kits are a natural pairing with these endlinks, giving enthusiasts a complete solution for tightening up chassis dynamics.

Exhaust & Finishing Touches

Kartboy's attention to detail extends beyond drivetrain and suspension. Their exhaust hangers are a testament to the brand's whole-car philosophy — even small hardware components are engineered and manufactured to the same standard as their headline products. Whether you're building a dedicated track car or simply want to eliminate slop from your daily driver, Kartboy has a thoughtfully engineered solution for your Subaru.

A Legacy Built on Trust

Over two decades later, Kartboy is still known for no-nonsense performance, bulletproof quality, and a fiercely loyal fanbase. In 2025, Kartboy teamed up with the crew from Company23 and BuiltRight Industries to carry the brand forward — honoring the legacy while doubling down on innovation and new product engineering. For Subaru owners who demand the best, Kartboy continues to be the benchmark.