The Öhlins Road & Track coilover system (part BMS MI30S1) is a complete front and rear damper and spring kit for the E46 BMW M3, built on Öhlins' DFV (Dual Flow Valve) damping technology. The front is a McPherson strut mounted upside down, with one adjuster for compression and rebound and a separate spring preload adjuster. The rear is a conventional shock absorber with its own compression and rebound adjuster and preload adjuster. Owners on user forums describe a tighter, more controlled feel than factory dampers, with quicker response and better bump absorption than stock. Because the dampers are rebuildable, owners can later have them revalved for a more track-focused setup, which makes this a long-term E46 M3 track day suspension rather than a short-term street upgrade. Öhlins also lists a 2 year warranty and salt spray testing to ISO 9227.
The manufacturer lists this kit for the BMW M3 (E46), year 2000 – 2005 and it is designed to use with original top mounts, so you keep your factory upper mount hardware. Front lowering is listed at approx. 15 - 35 mm lower than standard with recommended setup, and the rear at approx. 5 - 30 mm lower than standard with recommended setup. For DIY work, owners on user forums report that install took a little over 3 hours and then it was off to corner balancing, and a proper alignment is essential after any coilover install. Öhlins publishes a Mounting Instruction and owner's manual for this kit, so review them before starting. Searches for E46 M3 coilover kit, DFV coilovers, E46 M3 corner balancing, and E46 M3 track day suspension all match this product.
The manufacturer's listing includes the BMW 3-Series (E46) from 1998 to 2005 alongside the M3 entry, and it notes that top-mount usage is different for non-M models. Confirm the top mount requirements with the manufacturer before ordering for a non-M car.
Owners on user forums note that they are about 4" diameter and are meant to sit with stock top mounts. Narrower springs are a common track choice, but this also requires a change in diameter of the mounts/perches to accept a smaller diameter spring.
Owners on user forums recommend a professional alignment with corner balancing after installation. One owner reported that they use the latest hunter force equipment to align and corner weight the car.
This is a substantial job rather than a bolt-on. Owners on user forums describe about three hours of installation followed by alignment and corner balancing, and experienced owners advise against casual shop installation for this kit. The manufacturer's kit includes the hardware and mounting instructions, so work through the official instructions, safely raise and support the car on jack stands, and budget time for a proper alignment. Keep in mind that the front spring is large in diameter, so spring choice affects which perches or mounts you need.
