Quote:
Originally Posted by COcyclist
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At the time, they were often called the world's most aerodynamic production car. A slightly later model, the CX, was named for coefficient of drag, Cx. The SM's Cx (or Cd) is sometimes quoted as .26, although I remember .30 being usually seen. (But this article shows it higher. The article makes the good point that the value depends strongly on the wind tunnel used.)
Aerodynamics
A glutton for punishment, I had the SM and a DS21 at the same time. Both were fun to drive and own. Almost everything was different than in other cars. The SM had self-centering steering with just two turns lock to lock. The assist would vary with road speed, a new idea at the time. The self- centering worked even at a standstill, so you could crank the wheel over to full lock, release the wheel, and it would center itself.
The ride height could be set anywhere from about 4" clearance to 12" clearance ( and it self-levelled to adjust for any load). The extremes were used for jacking the car: you raised it all the way, put a special jack stand on a boss on the chassis, and then lowered the car all the way, and the support-side wheel would be off the ground (lifted by the antisway bar).
I used to lower the car when I parked. Then I'd come out, and if there were people around, I'd get in, start the car, set the ride height back to normal, and then get out. The back, being lighter always came up first. So I'd walk around to the back and pretend to lift that end. I'd have enough time to then walk to the front and pretend to lift that end. Got some great looks!
The brakes were operated by a servo valve instead of a master cylinder. (Brakes, steering and suspension were all operated by the central hydraulic system.) There was a mushroom-shaped button on the floor that moved a total of about 1/4 - 1/2 inch. This had a feedback loop that pressed the button toward your foot according to brake pressure. Worked very well but took a few stops to get used to the quite powerful brakes -- which recorded shorter stopping distances than all other cars of the time in some tests. It was fun to have friends drive the car: most would weave all over the road, over-correcting steering, and many would come to a few quite abrupt stops.
Then there was the great looking four cam Maserati engine, which performed pretty well and didn't catch on fire with every start... just a few. Three dual throat Webers were used with velocity stacks hidden by the aircleaner plenum. No chokes, just mixture enrichers -- which I think may have been manually operated. Lot's of overlap and low velocity through big throats lead to some spitting back and an occasional backfire. But what's an Italian engine without some drama?
Mine had US headlights: just 4 ordinary fixed-mount sealed beams. You could not have covers over headlights back then in the US. The European lights were covered, so the whole front of the car was glass. There were 6 lights and the middle two steered and self-levelled, so that under hard braking, you could still see out ahead.