QA1 DD901 Proma Star Double Adjustable Custom Mount Coilover Shock 8.6 in Stroke

Vehicle Fitment

• Universal Fitment - Designed for custom chassis, hot rod, restomod, street rod, and performance builds requiring a custom-mount coilover shock with 8.6-inch stroke

Fitment Notes

• Custom mount design - not a direct bolt-in; mounting hardware must be adapted to the specific chassis or suspension location
• Designed to use a 14-inch coilover spring with 2.5" I.D. (spring sold separately); recommended ride height is 18 inches
• Can be mounted in any orientation - body up or body down - with no change in performance
• Multiple mounting configurations available: bearing mount (1" wide x 1/2" bore) or bushing mount (1-1/4" wide, with 1/2" or 5/8" sleeves)
• Spanner wrench P/N T114W or T115W required for ride height adjustment (sold separately); optional thrust bearing kit P/N 7888-109 also available
• Register at QA1 before installation to activate Limited Lifetime Warranty

Features

• 324 valving options - 18 independent compression positions x 18 independent rebound positions for precise, full damping control
• Double adjustable valving with evenly spaced clicks - no jumps between any two adjacent settings for smooth, predictable tuning
• 8.6-inch stroke and 18-inch recommended ride height - well suited for taller street rod, restomod, and custom rear suspension builds
• Ride height adjustable via threaded aluminum shock body for stance and weight transfer tuning
• Precision machined aluminum piston with PTFE piston band for smooth, consistent, low-friction damping
• 5/8-inch centerless ground, hard chrome plated solid piston rod for long-term strength and seal performance
• Three-step sealing system for superior reliability under street and track conditions
• Lightweight 2-inch O.D. aluminum body for reduced unsprung weight
• 100% dyno-tested and serialized for verified, consistent performance
• Revalveable and rebuildable by the QA1 factory or QA1 Authorized Service Centers
• Made in the USA - Limited Lifetime Warranty (register before installation)

Specifications

• Part Number: DD901
• Type: Proma Star Double Adjustable Custom Mount Coilover Shock
• Compressed Length: 15 inches
• Extended Length: 23-5/8 inches (23.625")
• Stroke: 8.625 inches
• Recommended Ride Height: 18 inches
• Body O.D.: 2 inches
• Body Material: Lightweight Aluminum (Clear Anodized)
• Piston Rod: 5/8" Centerless Ground, Hard Chrome Plated, Solid
• Compression Adjustment: 18 positions (independent)
• Rebound Adjustment: 18 positions (independent)
• Total Valving Combinations: 324
• Recommended Spring Length: 14 inches (sold separately)
• Spring I.D.: 2.5 inches
• Mount Orientation: Any (body up or body down)
• Warranty: Limited Lifetime (register before installation)
• Made in the USA

Included Components

• 1x QA1 DD901 Proma Star Double Adjustable Coilover Shock Body
• 1x Spring Mounting Hardware Kit

Product Description

The QA1 DD901 is a Proma Star double adjustable custom mount coilover shock featuring an 8.6-inch stroke, 15-inch compressed length, and 23-5/8-inch extended length - making it the longest-travel option in QA1's standard Proma Star lineup and well suited for taller street rod, restomod, and custom rear suspension builds with an 18-inch recommended ride height. Like all Proma Star shocks, it is a universal custom-mount design intended for applications where a direct-fit shock is unavailable or where the suspension has been significantly modified. It accepts a standard 2.5" I.D. 14-inch coilover spring, allowing builders to independently select spring rate and ride height.

With 18 independent compression positions and 18 independent rebound positions, the DD901 delivers 324 total valving combinations with smooth, evenly spaced clicks across the full adjustment range. The 2-inch O.D. lightweight aluminum body, 5/8-inch chrome plated solid piston rod, PTFE-banded aluminum piston, and three-step sealing system provide long-term reliability on both the street and strip. Each unit is 100% dyno-tested and serialized and is fully revalveable and rebuildable by QA1. Register at QA1 before installation to activate the Limited Lifetime Warranty.