Objective Stage 3: Boiserie's M4 Rocket Bunny transformed for the track

To give this M4 a new visual identity, Lucien and his team opted for a wide body kit originally intended for an F80. The price of an original Rocket Bunny kit was prohibitive, so the team decided to adapt a more affordable kit:

• Made-to-measure cutting and fitting
• Shape work and fluid integration
• Full paintwork in the original colour

The transformation is completed with Vossen wheels, a bonnet, a boot and a carbon front end. The whole package retains the car's original aggressive character, while giving it the 'wide kit' look that has become something of a signature of Lulu's BMWs.

An aggressive design is not enough to shine on the track. You need a high-performance, well-balanced chassis. The preparation incorporates performance parts to improve stability and driving precision.

Improved braking

• Installation of bowl brakes
• Addition of aviation-type hoses
• Use of Motul RBF 600 high-temperature brake fluid

Installation of sports suspension

• Fitting KW adjustable suspension
• Addition of H&R anti-roll bars front and rear

Objective: to limit roll, improve cornering precision and optimise comfort without sacrificing performance.

Before any installation, Nicolas precisely measures the body height at the four corners of the vehicle. The results were clear: there was an imbalance between the front and rear, and between the left and right sides.

KW adjustable springs help to correct this imbalance, but to go one step further :

• Removal of rear adjustment rings for extreme lowering
• Provision of custom springs if the level remains too high at the rear

This configuration ensures maximum lowering, while retaining the original pilot-operated suspension, an important factor in maintaining the comfort and versatility of the M4.

Currently equipped with a Stage 1, the M4 develops around 700 bhp. But Lucien has no intention of stopping there. The next stage of preparation involves

• Upgrading to a full Stage 3
• Installation of a new turbo, an optimised intake and a more efficient exhaust system
• Installation of a multi-fuel map (SP, ethanol or mixed)

The aim is to reach the 800bhp mark, while retaining a handling consistent with rear-wheel drive.

Once the suspensions have been installed, the team carries out a complete geometry of the vehicle. This stage is essential for :

• Align the running gear perfectly
• Ensure precise steering
• Maximise grip on the track

The result: a lowered BMW M4 with a balanced stance, ready to take on the curves of the racetrack. The total cost of this modification: around €1,400 inc VAT, including spring kit and geometry.

Thanks to a thorough chassis preparation and some pertinent technical choices by the Shiftech teams, Lucien's M4 Rocket Bunny has been taken to the next level.

With its controlled lowering, preserved comfort and improved performance, this project shows that it is possible to combine extreme aesthetics with efficiency on the racetrack.

What's next? Installation of the brakes and engine preparation. See you in the next episode to discover the final version of this M4 with character.