Detroit Speed Mustang Showcases New Fox Body Suspension Solutions
In a world where Fox Body Mustangs have become the canvas for every kind of build, Detroit Speed took the opportunity to make its 1989 Notchback stand out. The time-warped IMSA-themed track warrior was built to serve as Detroit Speed’s proving ground for its latest products. This car was designed from the ground up to develop and showcase Detroit Speed’s full lineup of Fox-specific suspension and chassis systems, ultimately to turn heads at shows and rip corners at autocross courses. It’s a no-compromise machine with competition DNA and a very clear purpose.
At its core is a Ford Racing 363 cubic inch small-block, fed by a Holley EFI system and controlled through a Holley Terminator X ECU and a 12.8-inch Pro Dash. It’s backed by a Tremec TKX 5-speed and Detroit Speed’s FN988 gear set in a full floater rear axle assembly—because when you’re pushing a car this hard on track, conventional axles aren’t going to cut it. That same mentality carries into every corner of the car, literally.
Detroit Speed’s SLA front suspension conversion ditches the factory strut setup and replaces it with a proper short-long arm design. That completely transforms how this Mustang handles, especially under high load or rapid transitions. Not a mere suspension upgrade, the SLA kit is a redefinition of what a Fox Body front end is capable of. Paired with double-adjustable JRI coilovers, the tuning window is wide open for any track, tire, or driving style.
Out back, Detroit Speed's Speed Kit 3 coilover conversion replaces the clunky factory four-link with a serious competition-grade setup that finally gives the rear end of a Fox the same level of refinement as the front. That system works in harmony with Detroit Speed’s mini-tubs, subframe connectors, and rear Exo-brace to make the chassis not only stiffer but more capable of putting down serious grip. And with the Baer/Detroit Speed brake package clamping down on Rocket Racing Flare wheels, this thing stops as well as it goes.
The car also features a full custom roll cage, Detroit Speed battery relocation, seat sliders, and a hooker crossmember under the TKX. With support from Holley’s fuel pump modules, Earl’s AN plumbing, and a PWR cooling setup, this build is race-proven.
From the livery that nods to ’80s IMSA Mustangs to the cutting-edge components underneath, this Notchback is a test mule with attitude, engineered to push the limits of what a Fox Body can be. When Detroit Speed wanted to show what its suspension could really do, it didn’t just build a any car—it built this car.
Detroit Speed Suspension Upgrades for the Fox Body Mustang (1979–1993)
Detroit Speed delivers a complete lineup of suspension and chassis upgrades that bring modern performance, improved geometry, and premium build quality to the Fox Body Mustang. Whether you’re after bolt-on precision or race-level performance, these systems are designed for builders and drivers who expect more from their chassis. At the top of the range is the SLA system and rear Speed Kits, but every component plays a role in transforming how the car drives, handles, and looks.
Short Long Arm (SLA) Conversion System
The SLA conversion is Detroit Speed’s no-compromise front suspension system. It replaces the entire strut-based setup with a true double wishbone design that delivers optimized camber gain, roll center height, and improved tire clearance, especially at full lock. Forged aluminum uprights with hubpack bearings pair with JRI double-adjustable coilovers and a 1-7/16” adjustable sway bar to provide tunable, race-capable suspension with street manners. Clearance for 275/35R18s on a 10” rim means no compromises on tire size.
Front Suspension Speed Kit
This is the go-to bolt-on solution for Fox Body owners who want track-capable handling without fabrication. It includes forged 2” drop uprights, caster/camber plates with Speed-LIGN™ tech, QA1 adjustable struts, and tubular control arms with a Weight Jack system for easy ride height tuning. You also get S550 brake compatibility and optimized Ackermann and bump steer geometry in a 100% bolt-on format.
Weight Jack Lower Control Arms
These arms offer improved geometry, more tire clearance, and tunable ride height in a package that bolts into stock K-members. SN95 ball joints, Delrin™ bushings, and 700 lb/in Detroit Speed springs provide a responsive, comfortable ride with the ability to corner balance and fine-tune stance with ease.
Lowering Hubpack Uprights
Forged aluminum construction with a built-in 2” drop improves stance, reduces deflection, and delivers crisp steering response. Compatible with S550 brakes and designed to reduce bump steer and spindle flex, these uprights modernize braking and steering in any strut-based Fox Body.
Caster/Camber Plates
The Speed-LIGN™ system in Detroit Speed’s caster/camber plates gives you repeatable 1/16” alignment adjustments that stay locked in. These are a must-have for serious street or track builds running aggressive alignment specs.
Tubular Front Sway Bar
This 1-7/16” adjustable sway bar adds front-end stiffness while improving wheel and engine clearance. It’s designed to clear Coyote swaps and big wheel/tire combos, and it comes with all necessary hardware for a clean, bolt-on install.
Fender Apron Panels
For builders who want the cleanest engine bay possible—and need more clearance to support the SLA system—Detroit Speed’s fender apron panels deliver. Made from smooth 18-gauge steel, these aprons eliminate factory clutter, increase chassis stiffness, and improve tire clearance. They require fabrication and component relocation, but the result is a show-quality engine bay that works better on the street or track.
Rear Coilover Conversion Kits
The Detroit Speed Rear Coilover Conversion Kits upgrade your Fox Body Mustang with modern coilover technology, delivering vastly improved ride quality, handling, and adjustability. Featuring “Detroit Tuned” valving, this bolt-on system relocates the shocks and springs to the frame rail for added strength, increased tire and exhaust clearance, and a clean path for future mini-tub installation. With laser-cut brackets designed for OE frames and axles, it’s a smart, high-performance solution for builders looking to bring 21st-century suspension performance to their classic Mustang.
Rear Speed Kits
The Speed Kit Rear Suspension Kits from Detroit Speed deliver a comprehensive, race-proven upgrade for your Fox Body Mustang by combining a rear coilover conversion, Swivel-Link™ control arms, and a chassis-mounted rear sway bar. The coilover system brings modern ride and handling with JRi’s adjustable shocks, optimized mounting for strength and clearance, and compatibility with Detroit Speed mini-tubs. Swivel-Link™ arms eliminate bind and simplify pinion angle adjustment for better traction and reduced drivetrain vibration, while the chassis-mounted sway bar minimizes body roll and maximizes articulation without bind. This kit transforms your Fox Body into a precise, street-friendly performance machine.
Detroit Speed also offers a complete line of parts to refine your Fox Body, from platform-specific chassis stiffening kits to electrical and plumbing products, interior enhancements, and much more,
Every component is engineered and manufactured in Mooresville, North Carolina. Detroit Speed products are built for builders who don’t settle, and every piece is backed by a two-year limited warranty. Whether you’re doing a full SLA swap or dialing in geometry with bolt-on upgrades, Detroit Speed gives your Fox the capability—and credibility—it deserves.
