A High-Point for FWD? The Citroën SM
Gorgeous Bodywork, A Maserati Heart and oodles of curiosities, is this one of the greatest FWD cars of all time?
For all the derision it receives the FWD drivetrain has produced some truly great vehicles. While they may be flawed and may lack the appeal of AWD and RWD cars such as the Alfa Romeo 147 GTA, Golf GTI, Civic Type R and numerous fast Renaults have all cemented themselves as brilliant cars in their own right.
But hailing from the 70s is a unique piece of French motoring history. The SM, a collaboration between the innovators of mainstream front wheel drive and one of the great Italian supercar manufacturers. The Citroën-Maserati as it became known was released in 1970 as a sporting alternative to the high end DS Pallas and as was typical for Citroën at the time it was completely different from everything else on the market.
The sumptuous interior, complete with 'mushroom' brake pedal, obligatory Citroën single spoke steering wheel and a gorgeous chrome gated shifter. (Image Credit to Collecting Cars)
Firstly the body; penned by Robert Opron it was uniquely gorgeous. The overall smoothness of the shape contrasted nicely with a handful of lines cutting through it . Swathes of glass made for a capacious and light cabin. Glass covered the lights and front number-plate as well making for a truly unique visage that remains eye catching to this day.
And then there was the engine. Where the DS had an asthmatic four cylinder dating back to the 30s. The SM would share the beating heart with the Maserati Merak, a 2.7 Litre, Quad Cam V6 delivering 178 BHP (131 kW) and a wonderful six cylinder rasp. Performance was on par with RWD competitors during the 70s, with 0-60 in 8.4 seconds and a top speed of 137 MPH (220KM/H) which made it the fastest FWD car in the world for many years. But performance was not the be all and end all of the SM.
Beneath all the Hydraulic components lays the beating heart of a Maserati Supercar.
Hydraulics. As was customary for Citroën at the time everything was hydraulic. And I mean everything. Brakes, steering, clutch and suspension were all hydraulic. The system meant the car sat uniquely low when not in use, barely millimetres above the ground. When running the driver could choose from four settings, one for normal driving; a lower, firmer setting for spirited driving and and a raised setting for rough roads. The fourth, highest setting allowed the driver to change a wheel without the use of a jack. The system operated at 1088PSI (75 Bar) and comprised of suspension spheres, made of metal and half filled with hydraulic fluid and half filled with nitrogen. This created a perfect spring and gave a ride so smooth it has often been referred to as 'magic carpet ride'. Furthermore the suspension did not wallow when put in 'firm' mode, giving the car excellent handling.
The Hydropneumatic suspension at its highest. (Image credit to Motor1)
Further hydraulic innovation was present in the steering. DIRAVI as it was coined gave a steering setup that was and still is truly unique. The steering rack has a very fast ratio for a road car, 2 turns lock to lock. This meant the movements required were small and many find it takes 50 miles (80KM) to fully get used to the steering. Not only was it geared fast it would self centre when the car was stationary, the level of resistance would increase with speed - giving effortless manoeuvrability at low speed and solid resistance at higher speeds. But most curiously the steering eliminated all feedback, while this seems insane there was some method to Citroën's madness. Due to the huge pressure of the hydraulic system that ran most of the systems in the car it was found in testing that road feedback was both too forceful and exaggerated by the hydraulics, so Citroën's solution was to just remove the feedback. The car was truly point and squirt, the steering would do only as the driver directed. The steering was not however, devoid of feel - the car transmitted a clear sensation to the driver, DIRAVI simply would not allow anything other than the driver turn the wheel. Furthermore the brake system was fearsome, the hydraulics meant the all round disc brakes could pull the car to a stop in a shorter distance than any other car at the time - all from the brake 'mushroom' pedal that also requires a massive amount of getting used to thanks to the minuscule pedal travel.
The SM sat low to the ground. (Image Credit to Coys of Kensington)
The result of this hydraulic lunacy was a charming and interesting driving experience that remains totally unique. This perfectly encapsulated old school Citroën and gives insight into a more refreshing time in the automotive world, they did things their own way, unapologetically and with a wonderful flair. This defiant non-conformity produced some of the all time great automobiles - just look at the DS. But yes this system had flaws. If the car was to break down then you are in for a whole world of pain. Steering will become close to impossible, the brakes won't work and if the car is stuck in gear, you've got no clutch so good luck pushing it. But worst of all is the loss of hydraulic pressure in the suspension. The car will sag down just millimetres above the ground. So low in fact that even low loaders designed for supercars will have serious trouble picking it up. The reality of this is that to get the car loaded in a breakdown, the only option is to crank the car on the starter motor to build enough hydraulic pressure to raise the car. While in this worst case scenario the car's setup is close to useless, the rest of the time the system is unique, and has numerous merits.
A Short Wheel-base 'Breadvan' variant, intended for rallying and with another innovation - Carbon Fibre Wheels. (Image Credit to influx)
For instance. Hitting a pothole at 40MPH, an unpleasant experience. In a normal car the overriding sensation would be the jolt, or perhaps the steering wheel jumping out of your hands. Not in the Citroën. The most apparent sensation would be the noise. This incredible isolation in the driving experience made it an unrivalled choice for grand touring. Combined with the ability to firm the suspension and drive it hard the Citroën was a brilliant choice for many a situation.
So there we have it, a unique, classically french and effortlessly fast GT, but what do you think? A high point for Front-Wheel Drive or just another french oddity. Let me know in the comments.