What happens when the BMW M3 Saloon is put on a carbon rich diet? You’ll have this, the limited edition BMW M3 CRT. CRT stands for Carbon Racing Technology, and besides being motorsport inspired, the M3 CRT debuts a new production process for carbon-fibre reinforced plastic (CFRP) components.

For instance, the bonnet of the M3 CRT and the bucket seats for the driver and front passenger are made from a cellular carbon honeycomb, which is produced in a unique process pioneered for the manufacture of body components for the upcoming BMW i3 and i8, two new vehicles that will debut as part of BMW’s project i.

The process enables the cuttings left behind in the construction of the body to be reprocessed. The basic material (CF thread) can now be woven into CFRP mats of any size before being impregnated with synthetic resin and hardened.

Scheduled for a Frankfurt debut and volume production in 2013, the i models will feature a body consisting entirely of CFRP in the passenger cell area. For the M3 CRT, this allows the creation of a bonnet made from two CFRP mouldings encasing an aramid honeycomb structure, which is 50% lighter than the standard aluminium bonnet.

CFRP is also used for the car’s bucket seats. Here, the CFRP layers are wrapped around a recycled-paper honeycomb, with a better looking carbon layer (made using conventional production technology) added to visible areas. The rear spoiler and an air-channelling front lip are also from CFRP. A titanium muffler and model specific sound proofing are the other measures.

The M3 CRT’s unladen weight of 1,580 kg undercuts that of the standard M3 Saloon by around 45 kg. Take into account the equipment on board, BMW says the weight saving is more like 70 kg. A big portion of the saved weight is from the front end, which aids agility.

Under the CFRP bonnet is the M3 GTS’ high revving 4.4 litre V8, which makes 450 hp at 8,300 rpm and 440 Nm at 3,750 mm. Then engine features motorsport inspired details, such as a bedplate crankcase construction in a special aluminium-silicon alloy, individual throttle butterflies, a knock control system with ion current technology and a dynamically-optimised wet sump oil supply, among others. Power to the rear wheels travels via an M double-clutch seven-speed transmission with Drivelogic.

There are also some changes to the chassis. There’s now a rigid rear axle subframe and coilover suspension whose dampers are individually adjustable in their compression and rebound. The six-piston, fixed-caliper brakes – discs measure 378 x 32 mm at the front and 380 x 28 mm at the rear – are of a low-weight compound construction.

The new M3 variant also uses Stahlflex brake lines and model-specific brake pads. The Y-spoke M wheels are 19-inch items. DSC has been retuned to match the “greater dynamic potential” here as well as the changed weight distribution. Top speed is capped at 290 km/h.

Quite a nice last hurrah for the E90. Only 67 units will be available, but you can have your own, wallpaper, in the gallery after the jump.

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