This race car is quite unlike any other race E46 M3 in that it was not built from a BMW Motorsport shell. Having looked at the shell, we decided that overall it was compromised in design in ways we would not accept, and also dictated the use of more expensive BMW Motorsport only parts. We wanted to produce a very fast E46 M3 that was cost-effective to run and for significantly less than the typical M3 GTR build, which can be incredibly expensive.
We started with a road car – but not any road car! We actually took an M3 CSL road car and stripped it entirely. These are readily available now for not much more money than a normal M3 coupe, and have expensive items such as the carbon roof and carbon airbox already in place. The entire shell was reworked heavily with a full welded roll cage and many body sections drastically changed to save weight. Every body panel is made from carbon fibre, with all the windows in Lexan, except for the windscreen which is lightwight glass. Even the bottom of the car is flat bodied, ending a carbon underbody diffuser at the rear. The massive front splitter and rear wing add real downforce to the car.
The fuel system uses 2 submerged Bosch Motorsport fuel pumps in a custom Fuel-Safe bag tank which is situated where the rear passenger seat wells used to be, central and low in the car.
The engine itself is a totally standard M3 CSL engine, with Motec ignition pack and a Motec M800 ECU. Power is 380bhp engine dyno tested which is impressive for a totally stock engine! It is very economical to use and lasts for almost 2 seasons with no work. The clutch is a standard Tilton triple plate item with a lightened flywheel which mates to the Drenth 6 speed fully sequential gearbox. This wonderful unit features full throttle up-shifts courteosy of the Motec. A customised propshaft carries drive to a 4.1 Drexxler diff rebuilt by us to our specification, which in turn feeds uprated driveshafts with stronger inboard and outboard joints. The front wheels are 10×18″ and the rears are 11.5×18″. These 3 piece split rim wheels are designed and manufactured by us and are of the centre lock variety. This when coupled with the 4 built-in air jacks, allow the wheels to be changed in no time in the pitlane.
The brakes system is AP 6 Pot calipers upfront on 356mm discs with AP 4 Pot calipers on stock CSL discs at the rear, with no servo or ABS, and running Mintex FR2 pads.
Exhaust system has no cats, two centre silencers and two rear silencers exiting to two single exhaust pipes. It is relatively quiet at 104db. The interior features a Sparco Superlight carbon race seat, a Pro-drive carbon steering column and a Pro-drive pedal box. All the information is fed to the driver via the Motec ADL dash logger.
The chassis features Intrax 4-way dampers, H&R front and rear anti-roll bars, Simpson bushes all round and Simpson rear adjustable camber arms. The rear diff assembly is very modified to provide the maximum in rigidity.
Weighing in at 1120kgs and packing 380bhp it is significantly faster than the road car it was born from (nearly 9 seconds a lap quicker around Donington for example). Performance puts it up with Porsche GT3 cup cars and Ferrari 360 Challenge cars. It really punches above its weight thanks to great aerodynamics and a very friendly chassis.