In 1968 the groundwork was laid for the creation of one of the most impressive -albeit misunderstood- automobiles in history: Her majesty, the Citroën SM, the fastest front-wheel drive automobile for over 15 years.
Despite the fact that the Citroën DS23 did render over 140 HP thanks to its electronic fuel injection system and the different improved versions of its push-rod engine, the French car manufacturer still somewhat suffered form an inferiority complex vis a vis their competition due to the underwhelming performance of their engines.
This was to some extent justified: on the one hand the hydropneumatic suspension system used up some of the engine´s horse power in order to move the pump that pressurized the whole setup; on the other hand, these cars sported very robust frames as well as heavy and over-sized drivetrains (the SM´s curb weight reaches 1,400 kilos). But above all, these cars were capable of running very fast in such an effortless way that everything seemed too slow for them.
The signing in 1968 of the purchase agreement of Maserati by Citroën meant for the latter the opening of the gates of the organ bank of one of the companies with the best of reputations for building powerful engines. Gone is the inferiority complex!
That same year, the “Project S” started. Its goal was to create a high-performance automobile with a Maserati engine. For the first trials, the engine is assembled on a Panhard CT24 frame with a lengthened front end to accommodate the potent power plant.
Once the power train was set up, the Project S goes on with the trials of the groundbreaking hydropneumatic suspension system and engine mounted on a DS that had widened wheelhouses and a modified interior to be able to accommodate the whole of the power train assembly.
Finally, the Citroën SM -where S stands for the project´s name and M for Maserati, is unpretentiously introduced in its final shape and body in the Geneva car show in March 1970 and then in a full-fledged way in the Paris car show in September of that same year.
Despite the fact the SM was (and some of its features still are) a revolutionary vehicle, its impact was not on a par with that of the Citroën DS, which 15 years earlier had utterly overshadowed every vehicle introduced at the 1955 Paris car show. However, the SM did not at all go unnoticed, and it set new records from its inception.
Citroën SM: Her Majesty´s milestones
At the time of its release, the Citroën SM was the fastest front-wheel drive car in the market. Despite the fact that the 170 HP of the carburettted version seemed laughable when compared with the 325 HP of the Oldsmobile Toronado, the Citroën was much lighter and aerodynamic, and was thus capable of reaching 220 kph.
This speed was the record for a front-wheel drive car until 1983, when the low-sitting Audi 200 Turbo Typ 44 came out, with its flush mount glass and a formidable drag coefficient of 0.33.
However, the ability to reach 220 kph was not the most outstanding thing, but the ease with which the car was able to ride at speeds that its competitors struggled to attain. The key for this was the groundbreaking hydropneumatic suspension, steering and braking system, much more advanced than the one present in the Citroën DS.
It took the steering wheel only two full turns lock to lock, and on top of that the car´s steering featured a state-of-the-art power assisted centering system called ‘Diravi’, which allowed the steering wheel to return to the center even when the car was parked. This meant that the steering of the Citroën SM was twice as responsive as any of its competitors´, something that the drivers at the time were not used to.
The brakes on the SM were also improved and its stopping power was astonishing -it was the car with the shortest braking distance of its kind, as was the stability supplied by its self-leveling or driver-variable ride height suspension.
The body was designed by Robert Opron, the genius who had redesigned the front end of the DS and was responsible for the aerodynamic lines of the Citroën CX and the exclusive Alfa Romeo SZ sports car, which incidentally had a front end that sported 6 square headlights reminiscent of the SM.
From outside, the car´s low stance and its wide and glazed front end made it look like a flying saucer. The interior was also remarkable, its lines so modern that one might think they belong to a car form today, the seats are extremely comfortable and they look impeccable.
Despite all these features, the SM only ranked third -with 105 points, among the candidates for the European Car of the Year prize in 1971, falling behind the Citroën GS -133 points, and the VW K70 -121 points, which was an NSU in actuality.
I suppose it is true what they say, that “you can´t be a prophet in your own land”, and so the following year the SM was the top choice for 1972´s Motor Trend Car of the Year at the other side of the pond. That was probably the reason why the producer of The Longest Yard chose the Maserati SM -thus commercialized in America, to be featured in one of the saddest-ending car chases in the history of cinema with Burt Reynolds sitting at the wheel.
The Citroën SM and Burt Reynolds in movie history
Citroën SM Maserati: The cursed engine
Citroën had high hopes for the SM, a car where all the groundbreaking features of the DS had been refined and that was powered by a formidable 2.7 liter V6 Maserati engine under the hood, that rendered 170 HP in the early carburetted versions and 178 HP in the fuel injected ones -equipped with the Bosch D-Jetronic fuel injection system introduced in 1972.
Finally, the engine rendered 180 HP when the displacement was raised to 3.0 liters in the 1974 and 1975 carburetted versions.
Unlike boxer engines, V-shaped engines accommodate two connecting rods in each crankpin. Since you have to divide the 360º of the circumference among 6 cylinders, for the tuning to be perfect, the usual thing is for each of the banks of the V shape to form a 60º angle (6×60=360).
This way, the explosions are perfectly synchronized and “equidistant” each turn of the crankshaft. Conversely, the banks in a V8 engine usually form a 90º angle, so that each turn of the crankshaft 4 cylinders are balanced (4X90=360).
There are exceptions, such as the Porsche 928´s V8 engine, whose banks form a 120º angle due to the fact that the main aim was to lower the center of gravity of the car and to build a front end that was as low and aerodynamic as possible. The usual thing, however, is to seek a well balanced working of the engine.
The banks of the SM V6 engine form a 90 degree angle, which is unusual. Since Giulio Alfieri, the engine´s famed designer, had also created the wonderful Maserati V8 engine, most people assume that the V6´s peculiar design is simply due to the fact that, due to lack of time and funding, two of the 8 cylinders were eliminated from Alfieri´s V 8. This theory, however, can not be proved as there is no evidence to support it.
Also, there are numerous sources that claim that the V shape was widened to leave more room between banks, causing the engine to be lower and wider.
Personally, I think the first theory is more reasonable than the second, which almost sounds as an excuse.
If the timing chain had been located in one extreme of the engine, I would heed the second theory, but seeing how it is situated amid the cylinders in an unsymmetrical way -there are 4 cylinders behind it and 2 in front, I am inclined to think that the engine was originally conceived as a V8, due to the fact that symmetry is always sought in order to avoid any possible unbalance, and so, that timing chain in the middle of the engine block makes sense in a V8, not in a V6.
Admittedly, the engine´s performance is very good considering its displacement and the time it was designed, but smoothness was never its forte, precisely because of the angle of the cylinder banks, which confers it a very distinct sound due to the firing order of its pistons.
Alfieri´s V6 made the SM a huge success, turning it into a high performance grand touring car, able to accelerate from 0 to 100 kph in just 8.5 seconds and to reach speeds over 220 kph. However, it was also part of the car´s black legend.
The engine´s all but 180 horses were thirsty, so the 1973 oil crisis made a huge negative impact on sales, specially in Europe. For many, this is the main cause the wonderful run of the Citroën SM came to an end only 4 years after it had started, 1975 being the last year of production.
Rumor has it, though, Peugeot -which had purchased Citroën in 1975, did not quite look kindly on the fact that a Citroën model was light years ahead of the best Peugeot, a theory that I find very likely if you ask me.
However, it is an undeniable fact that the SM´s V6 engine will also be remembered for its unreliability. The irregularity of its explosions due to the angle of the cylinder banks and the attachment of the air conditioning compressor -which is constantly engaging and disengaging, expose the timing chain to strong vibrations, which end up breaking it and thus ruining the engine.
Luckily, nowadays this issue can be solved by purchasing a kit to make the engine more reliable, but its cost is high and few owners take the trouble, although undoubtedly the SM deserves it.
The fuel-injected versions equipped with the D-Jetronic system also have a bad reputation for it being too complex and their tendency to catch fire.
The temperature that accumulates at the center of the engine bank and fuel leaks in the numerous hoses for the fuel injectors, fuel pump etc contribute to the problem, which is however very easily solvable: it all comes down to using top quality hoses and hose clamps and to check them regularly.
Citroën SM M-4939-AB, a rising star
I can remember the first time I ever saw a Citroën SM as clearly as if it had happened yesterday. I was walking with my dad in front of the old Trianón Theater in León when suddenly there appeared the six head lights behind their glass nacelle and an Oviedo license plate in the middle.
I must have been 4 or 5 years old and was barely tall enough to see the hood of the car, which looked huge to me. It was a beautiful dark metallic blue, and I haven´t been able to get that car out of my head ever since.
Thanks to the internet, a friend told me about “one of those SM cars that you like” for sale in Santiago, so I contacted the owner to ask if I could test-drive the car in order to publish my impressions in my blog.
That´s how I met Gonzalo and thus proceeded with this one-of-a-kind test drive.
The first thing that catches the eye upon arriving before the SM is its likeness to a crouching sphinx. After sitting for a few hours, all the pressure is gone and the car lowers to the point that it almost scrapes the ground. This is normal, but visually it makes its 4.89 meters in length reach gigantic proportions.
Once started, the sound of its V6 engine really grabs our attention. Despite the newly built steel exhaust the car has, there is a small leak in the gaskets behind the first muffler, nothing worrying as it is something easily fixable: you just need to tighten the clamps and install a copper O-ring. Nonetheless, the issue somewhat spoils the beautiful sound of the V6 engine.
Little by little, the cat awakes and stretches its limbs, as if bowing: the front legs first, then the hind legs, readying itself for the hunt.
My dad did not want to miss out on the opportunity to find out how it feels to drive such a special vehicle, so to get out of town I ride in the back seat, which has a very easy access, thanks to the huge doors and the front seat, which can be folded and moved forward.
The back of the car is surprisingly roomy, we are not dealing with a 2+2, but a veritable 4-seat coupe. The seats are not only a thing of beauty, but also very comfortable.
The car´s interior is in really good nick, there are no loose parts or broken panels, and the seats are in fantastic shape.
The dashboard´s design looks still modern 45 years after the car was released, even the brushed aluminum used for embellishment is totally in-style nowadays. It even has a folding car key, as modern cars have. Only the radio, the handbrake lever and some of the knobs and buttons give the SM away and we are reminded that we are dealing with a car from the 20th century.
When we get to the spot where I am going to take the pictures I can see everything at ease in the daylight. The bodywork is in very good condition, there are no serious rust spots, and although its state is not perfect -there are body panels where the paint has a different hue , this is something normal.
The SM is a very long car and its wheelbase is huge -almost 3 meters, so it is easy to see how someone could make some scratches to it when parking , specially when we bear in mind that the front end is really wide -1.83 meters.
The SM´s body is full of design detailing, from the glass-covered headlights and front license plate, to the air vent situated under the bumper, which cools the radiator, or the two air inlets that funnel the air to the brake discs -that are in turn situated behind the differential in order to minimize the suspended weight at the wheels for better stability and grip.
I love the car´s front end, the rear view mirror, the view form the tail… I fall in love with the SM from every angle I look at her.
The trunk has been recently re-upholstered and there is no trace of rust in it. Rust is a typical problem in this area in cars with hydropneumatic suspension, as they sit so close to the ground that they sometimes come into contact with the wet grass, which may cause the body to rot. In this particular case, the bodywork is in very good condition.
Unfortunately, when the car was designed somebody must have forgotten to include room for the spare wheel , which takes up a great deal of the trunk´s space.
Air conditioning, self-leveling, swiveling headlights -although they are not functional in this particular unit, they can surely be easily put back into working order, electric windows, variable power steering, self-leveling suspension… it might appear that I am describing a Porsche Panamera instead of a 1972 Citroën -although the license plate number is a 1973 one.
Finally, the moment I have been waiting for: I sit behind the wheel to experience the ride in this dream on wheels. The driving position is very comfortable. The seats are excellent and the steering wheel has a nice touch -even though the work of the upholsterer who worked on it is horrible.
Luckily this is not my firs test-drive on a Citroën and I quickly get used to the rubber mushroom brake button that the SM has in place of a brake pedal. The braking is regulated by the force one applies to it, but the button itself is zero-travel. Once you get used to it it makes you wonder why it is not so in all cars!
The steering is extremely responsive. Even though I have test driven modern cars where the wheel takes less than 2 turns lock to lock -the Mercedes A45 AMG takes 1 and ¾ , the SM turns much more, which means its steering ratio is lower. In addition, the steering is the most responsive I have ever tried.
One must be careful not to be caught off guard, as the first couple of turns the car will turn more than one could expect. Luckily, the rear axle is much shorter than the front axle or else the car would end up hitting the curb in every corner due to its long, 3-meter wheelbase. Once you get used to the SM´s steering quirks, the driving experience becomes unparalleled.
The gear selector is both beautiful and precise. Volvo did their own version of it for their V60 model but the latter´s beauty and touch can´t stand comparison with the original. The 5 gears engage with ease and precision, although their travel is lengthy, a consequence of the lever´s size.
Nonetheless, the lever´s position in relation to the steering wheel is perfect, thus making shifting gears a delightful experience.
The V6 engine is not fine-tuned. The D-Jetronic injection system is excellent, but it needs to be well adjusted to be able to perform at its finest. In this case, the air fuel mixture is too rich, and so the cylinders flooded if we step one the accelerator pedal in an abrupt way; it runs much more smoothly if we accelerate gradually, giving the air enough time to mix well with the gasoline.
I don´t think we are dealing with an internal engine problem because the car starts just fine and it does not smell like oil; actually, there are no oil leaks, which is remarkable.
However, the fuel injection system clearly needs adjusting, nothing that cannot be solved with some fine-tuning and by driving the car often enough in order to prevent the intake manifold´s pressure sensor membrane to get ruined.
As a classic car, the Citroën SM has only one flaw, namely, it has no classic-car feel: it was such a groundbreaking car when it was conceived, that today it drives like a modern car. Everything works really smoothly and the brakes are better than the ones some of the modern cars I test drive each week have.
The steering, the stability… everything about the car makes it difficult to believe that you are driving a car that was designed 45 years ago. Well, maybe the visibility does not.
The SM´s windshield pillars are much thinner than the Ionic columns that modern cars have for pillars, which makes the ride feel like you are driving on a balcony with a view to an enormous hood. If this car was mine, I think it would be my daily driver – well what the hey, I am sure it would.
The car driving ahead of me is a Mini Countryman. I can´t help but thinking that if it was bought new, the person who bought it will have lost more money in one year because of the car´s depreciation than the amount it would take to buy this SM, and the Mini is not one tenth as cool as the Citroën. Anyway, to each his own.
This particular SM specimen is not perfect, but the car provides an excellent basis for restoration: it has no rust, it is a complete car, and it is mechanically sound, despite the needed fine-tuning of the fuel injection system. I personally think this car is a good investment, and prices are on the rise.
The DS turns 60 this year and their prices are soaring. In 5 years the SM will celebrate its 50th birthday, and I am afraid by then their prices will be prohibitive.
It is always hard for me to say goodbye to the classic cars I test-drive, and this time it is even more so. This is, on the one hand, because the SM ranks very high in the list of my top ten dream cars. On the other hand, driving this car has made me think about how sad Carlos Tavares recent announcement of the end of Citroën´s hydropneumatic suspension really is, after bearing witness, once again, of how the French manufacturer had been able to set itself apart from the rest of their competition.
The SM is a unique car the like of which will never be built again, and one feels that it was designed by passionate and knowledgeable engineers. There is no more room in car making for flights of creative ingenuity, not even in Ferrari, Rolls and the like. Cost and the market prevail over other considerations, and marketing departments cut the wings of any attempt to veer off the trodden path. There is a Chinese proverb that goes: “the nail that stands out gets hit by a hammer”… and the SM stood out and towered above all others.
Now, she is mine…
Translated by Miguel Fernández Garrido