H&R Street Performance Coilover – BMW Z4 M Coupe / M Roadster (E85/E86, S54)

OVERVIEW

The H&R Street Performance coil over system replaces the factory struts and springs on the E85 BMW Z4 M Roadster and E86 Z4 M Coupe with fully threaded shock bodies and matched progressive-rate H&R springs. Ride height is adjusted at the spring seat, so the drop can be dialed in rather than fixed at a single figure.

Custom damper valving works with the progressive rate springs to keep the S54-powered Z4 M composed on a rough road while sharpening body control. The lower center of gravity reduces body roll and improves chassis balance and turn-in, and the reduced fender gap tightens up the car's stance.

H&R springs are crafted from a special 54SiCr6 spring steel and shot-peened to increase their life by more than 200%. All production is completed by H&R in-house, and every spring is 100% tested before leaving the ISO9001-certified production facility in Germany.

SPECS

• Approximate front lowering: 0.9" – 2.0" (height adjustable)
• Approximate rear lowering: 0.75" – 1.7" (height adjustable)
• Fully threaded shock bodies — ride height adjusted at the spring seat
• Custom damper valving matched to progressive-rate H&R springs
• Springs crafted from special 54SiCr6 spring steel
• Shot-peened to increase spring life by more than 200%
• All production completed in-house in Germany; each spring 100% tested
• Built to TÜV and ISO9001 quality assurance standards

PARTS INCLUDED

• Complete H&R Street Performance coil over kit as supplied by H&R Springs — fully threaded front and rear shock bodies with matched progressive-rate springs. See the installation instructions for the full bill of materials.

TECH RESOURCES

Additional Parts Required

• None. H&R specifies no additional hardware for this coil over kit.
• Four-wheel alignment after installation — H&R states that alignment must be checked after any suspension ride height modification.
• Professional installation — H&R states that its springs and suspensions should be installed by professional suspension mechanics only.
• Spanner/coil over wrenches and standard strut service tools, supplied by the installer, are needed to set and lock ride height.
• Confirm the car is not fitted with electronic/adaptive damper control before ordering — this is a passive, non-electronic coil over system.

Installation

• H&R Technical Information & Installation Guide (PDF) — spring markings, ride height measurement and adjustment, bumpstop trimming table, alignment requirements.
• H&R installation FAQ (hrsprings.com) — spring orientation, progressive rate springs, ride height measurement and post-installation alignment.
• Follow the factory service manual procedure for strut and spring replacement on the E85/E86 chassis.

PART NUMBER

• 29097-1

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