QA1 continues to push the envelope with its latest introduction—4-link kits for the street and the track. The HD Pro Rear Triangulated, and the HD Pro Rear Drag 4-Link Component Kits were created with the do-it-yourselfer (DIY) in mind. They are designed to streamline the fabrication process yet provide a professional-grade appearance and functionality for your Mopar, catering to your needs and preferences.

Above: The HD Pro Rear Drag 4-Link Kit contains trailing arm tubes, brackets, rod ends, and tube adapters. It also includes a 40-inch shock cross member, mounting tabs, grade 8 hardware, and installation instructions. Additional components that can be added or purchased as a package include a 40-inch diagonal link kit with mounting brackets and single, double, or MOD adjustable coil-over rear shocks. 

Both the HD Pro Rear Triangulated 4-Link Kit, the HD Pro Rear Drag 4-Link Component Kit, and the soon-to-be-introduced HD Pro Parallel 4-Link offer DIY buffs high-quality components. These components can be MIG or TIG welded, giving the installer the ultimate versatility and control over the modifications, ensuring resilience and performance.

All the USA designed QA1 suspension systems are built to deliver superior handling and reliable and repeatable execution. Enthusiasts will revel in the ease of dialing in the suspension geometry for street compliance or achieving maximum traction at the track. Regardless of the selected system, QA1 has the suspension solution and components for any Mopar.

Above: A 4-link rear suspension system is prevalent in high-performance vehicles due to its improved stability, traction, and adjustability. The primary benefit of a 4-link suspension is that it allows the user to adjust parameters like the anti-squat and anti-dive characteristics, which can help fine-tune the suspension’s instant center for specific driving preferences or track conditions. 

QA1 Product Manager Jesse Cowles stated,

“We recognize that old-school craftsmanship and ingenuity is alive and well within the car community. As much as we’d like to, we can’t create a direct bolt-in solution for everything. So we wanted to deliver a product for those customers who are willing to put some sweat equity into their build. We took the heart and soul of our 4-link systems and adapted them into several DIY 4-link kits. We’ve introduced solutions for both hardcore drag racers and street performance enthusiasts who might be looking for a triangulated 4-link solution.”

For the serious drag racer, the HD Pro Rear Drag 4-Link Component Kit is an exceptionally adjustable, no-nonsense resolution to enhance traction and rear suspension performance. The kit provides pinpoint instant center adjustments to set up the suspension to match the track conditions. The Pro Rear Drag kit is fully adaptable and can be cut to length to fit within frame rails of 40 inches or narrower.

The HD Pro Rear Drag kit includes heavy-duty 1-1/4” trailing arm tubes and ¼-inch-thick mounting plates engineered for the tremendous stresses on the rear suspension while drag racing. QA1 incorporates chromoly rod ends and Grade 8 hardware to offer incomparable strength.

Above: The HD Pro Rear Triangulated 4-Link Kit is better suited to street enthusiasts and those who enjoy spirited driving on twisty road courses. The stability, articulation, and compact design make the triangulated rear suspension a popular choice for high-performance vehicles where durability, handling, and simplicity are essential.

To keep the suspension squared correctly in the chassis, QA1 offers a lateral locating device and other components to complete a fully optimized drag racing suspension. The kit includes all the elements necessary for assembly and mounting. The all-in-one solution comprises trailing arms, shock cross member, and Grade 8 hardware. Lastly, detailed dimensional diagrams and renderings are provided to aid the installer with the suspension installation, ensuring a professional-level result.

Dave Knauff, Engineering Manager, mentioned,

“QA1’s new DIY 4-link kits are built tough with high-strength steel plates and tubes, plus grade 8 hardware for durability. The kits include everything you need, except for paint, welding wire, and gas—making them a complete solution for your custom suspension setup.”

QA1’s HD Pro Rear Triangulated 4-Link Kit is a flexible and adjustable option for the street and cornering crowd. Because of its triangulated design, there is no need for a Panhard bar or Watts Link to keep the suspension located correctly in the chassis. The kit is constructed with 1-1/2-inch lower trailing arm tubes, laser-cut brackets, QA1 chromoly rod ends, and Grade 8 hardware. It is engineered to survive the severities of daily and spirited driving.

Above: The HD Pro Rear Triangulated 4-Link Kit has trailing arm tubes, brackets, rod ends, tube adapters, a 40-inch upper trailing arm and shock cross member, and all the required hardware. Enthusiasts can purchase single, double, or MOD adjustable shocks with specific kits. 

Like the HD Pro Rear Drag kit, the HD Pro Rear Triangulated 4-Link Kit is designed for easy customization and can be cut to length on chassis rails of 40 inches or less. Each kit includes all components for installing the trailing arms, shocks, and springs. The kit can be matched with QA1’s coil-over shocks, adding to the suspension’s tunability. Lastly, the included dimensional diagrams and renderings reduce the installation complexity, affording a professional-grade fabrication.

Damien Brase, Product Manager, added,

“The little things are where we typically get hung up on projects, in the case of a custom 4-link, the spacers, right and left-hand jam nuts and the correct size tube adaptors for the tubing and rod ends can take time to order correctly. We put these 4-link kits together with the correct hardware, tubing, and brackets to help simplify these DIY 4-link installs.”

Above: The four links of a drag race style 4-link are sandwiched between double brackets welded to the frame and the rear end housing. The bottom links are usually installed parallel to the chassis, while the top links are angled down and forward. The imaginary point where the top and bottom links would intersect if extended forward is called the instant center. The location of this point in relation to the car’s center of gravity affects how the car launches. When the rear-end housing tries to rotate upward, it pulls on the top link and pushes on the bottom link. The rotation creates a leverage action centered around the axle centerline and is applied to the 4-link’s forward mounting points. The upper-link angles can be adjusted to improve the forward bite. Negative preload can be applied by lengthening the top right bar, which shifts weight to the back left tire. The more horsepower the car has, the more negative preload may be needed to keep the car driving straight off the starting line.

The yet-to-be-released DIY Parallel 4-Link Kit simplifies fabrication while offering professional-grade performance in an all-in-one bundle. Its low-profile design provides seamless installation and delivers an improved, uncompromising stance while affording excellent ride quality. The kit is perfect for DIY installers seeking enhanced adjustability and safety for their ride.

Regardless of which rear 4-link is selected, it will deliver supreme performance and provide nearly endless adaptability, making it essential for any serious builder desiring to upgrade their rear suspension for the street or track. For more information, contact the representatives of QA1 for all the latest on its suspension upgrade products.

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