BMW builds ultimate M3

BMW is set to cater for motorsport enthusiasts once again, with a limited edition, lightweight version of the M3 - called the M3 CSL - due to be launched in 2003.

Although only a prototype at this stage, the M3 CSL has quickly moved from concept to reality after an overwhelming response to the M3 CSL Concept Car shown at last year's Frankfurt motor show.

The CSL name is derived, in abbreviated form, from the three terms "coupe, sports and lightweight".

In bringing the CSL to production, BMW is continuing a tradition that started in 1938 when the company built the 328 Mille Miglia Coupe with an aluminium body and followed it up in the 1970s with a lightweight sports car based on the 3.0-litre coupe.

More recently BMW Motorsport built a limited batch of E36 M3s for the Australian market that were designed to be competitive in GT Production and Group N racing.

Called M3R, just 15 of the cars were built in the 3-Series coupe plant in late 1994, before being modified when they arrived in Australia in early 1995 using parts from the BMW catalogue, as well as from the European market M3 GT Le Mans car.

In comparison, the CSL will use both Formula One and aerospace technology in key areas in an effort to reduce weight and thereby improve the car's driving dynamics.

F1-derived carbon fibre reinforced plastic (CFRP) is used liberally in areas such as the front skirt flaps, roof and rear diffuser, while the front skirt as a whole is made of carbon fibre, as are the door inners, side sills and centre console.

The load-bearing structure supporting the through-loading system in the rear seat is made of endless glass-fibre thermoplastics, a material carried over from aerospace applications.

The front seats are made of glass-fibre reinforced plastic (GFRP), which makes them lighter than the standard seats in the M3.

Other weight concessions include the use of thin glass for the rear window, as well as the removal of air conditioning and audio systems, while the floor beneath the luggage compartment is a honeycomb sandwich plate and the material beneath the floor carpet is made of special lightweight foam.

The M3's 3.2-litre straight-six engine also comes in for some attention, with a new air intake and revised engine management for a slight power boost.

The CSL rides on specially developed, lightweight 19-inch alloy wheels fitted with semi-race Michelin Pilot Sport Cup tyres, which enclose a larger 18-inch braking system with reprogrammed ABS.

A similar program of modifications helped to reduce the M3R's kerb weight by around 100kg in roadworthy street trim, so by applying that formula to the current E46 M3's kerb weight of 1525kg, a mass in the low 1400kg region can be expected for the CSL.

BMW Group Australia has expressed interest in obtaining a limited number of M3 CSLs for the local market, but at this stage right-hand drive production has not been confirmed.

But even if RHD production does not eventuate, you can expect BMW Oz to still bring in a handful of cars - both for its own marketing purposes and well-heeled racing enthusiasts and collectors, if for nobody else - in much the same way as five of the left-hand drive only Z8 roadsters made their way Down Under a few years ago.