CT4-V Blackwing Sway Bar and "Spec-R" Lowering Springs by Swift Springs/RP USA Package

Unleash the full capability of your CT4-V Blackwing with the Refined Performance USA Spec-R Suspension Package — the ultimate pairing of Swift-engineered Spec-R Lowering Springs and RP USA Hi-Tensile Chromoly Sway Bars. Developed specifically for Mag-Ride equipped V-Series Cadillacs, this bundle is purpose-built for drivers who demand peak performance without sacrificing daily comfort.

What’s Included:

• Refined Performance USA / Swift Spec-R Lowering Springs (Front & Rear)

• RP USA 32mm Hi-Tensile Chromoly Sway Bars (Front & Rear)

• RP USA Polyurethane Performance Bushings

• All required hardware

Track-Bred Springs with Street-Driven Comfort

The RP USA / Swift Spec-R Springs are the only dual-rated, track-duty springs designed exclusively for Cadillac by RP USA and Swift — and only available through Refined Performance USA.

• Lowering Specs: ~20mm front & rear

• Spring Rate: ~30% stiffer than OEM

• Drop without compromise: Thanks to the unique progressive + linear wind configuration, the “tender” section supports proper ride height and Mag-Ride compliance, while the main spring body delivers race-day response and control.

• Material: Swift's exclusive H5S.TW alloy ensures lightning-fast transient response and a ride quality other springs can’t match.

Whether you’re daily driving or carving corners, these springs give you the balance of comfort and ferocity Cadillac’s Magnetic Ride Control was made for.

Massive Sway Bar Upgrade = Maximum Grip & Control

Pairing perfectly with the Spec-R Springs, our 32mm Hi-Tensile Chromium-Molybdenum Hollow Sway Bars (front & rear) transform your CT4-V Blackwing’s cornering capability.

• Material: Cold-formed CR-MO seamless steel alloy

• Construction: Hollow-tube design for optimal strength-to-weight ratio

• Fitment: Laser-cut, MIG-welded CNC bar ends ensure OEM-perfect alignment

• Performance: Reduces body roll, increases front/rear grip, and improves steering response and chassis balance under aggressive driving

Compared to OEM and even CT4-V Blackwing bars, these sway bars represent a massive step up in energy transfer and handling dynamics — keeping your tires flatter through curves, and your inputs sharper than ever.

The RP USA Advantage

• The ONLY Swift-exclusive spring solution for Cadillac

• Designed for full Mag-Ride compatibility

• Engineered, cold-formed, and precision-built in-house

• Battle-tested in real-world track and street conditions

Built to Dominate — Track or Street

With this complete Refined Performance Suspension Bundle, your CT4-V Blackwing won’t just look more aggressive — it will drive like it too. More grip. More confidence. More connection between you and the road.

Refined Performance USA. Designed to enhance. Built to endure. Engineered to win.