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 dialled 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 centre 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
Required Extras
- 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.
VEHICLE APPLICATIONS
| Make / Model | Chassis | Engine | Years |
|---|---|---|---|
| BMW Z4 M Roadster | E85 | S54 3.2L I6 | 2006–2008 |
| BMW Z4 M Coupe | E86 | S54 3.2L I6 | 2006–2008 |
H&R's official kit number for this application could not be verified on hrsprings.com, so no part number is published here. Please confirm exact fitment and part number with Speed Logic before ordering.