Tech Tuesday: The Porsche Sportmatic Transmission available in air-cooled Porsche 911’s starting in 1967 was actually not an automatic transmission because the driver still had to shift between gears. But, a clutch was not needed to shift. The first Porsche automatic transmission honor actually goes to the Tiptronic transmission since the Sportmatic still required driver input to shift gears.
The Porsche Sportmatic gear lever used a micro-switch that activated whenever the gear knob was depressed slightly. This caused a solenoid to open an pneumatic valve that activated a vacuum cylinder to disengage the clutch. The syncromesh gears could then be changed before the clutch is re-engaged when the gear lever is released.
The clutchless Sportmatic transmission used a torque converter from a traditional automatic transmission but still required a driver to shift the gears through the traditional H-pattern.
German engineering is usually very logical, but in the case of the Porsche Sportmatic the gears were labeled L, D, D3 and D4. Porsche encouraged using D for standard get-away from a standing stop while L was reserved for steep hills or inclement weather, similar to a 4WD transmission. For some reason D2 is missing and the transmission jumps from D to D3 and D4.
The Porsche Sportmatic was a $280 option in its day. As you would expect Porsche and sports car enthusiasts were not enthralled with the idea of a Sportmatic in a Sports Car. In a 1970 Car & Driver article they stated: “We don’t like it. We understand the reasons for it, but we disagree and we don’t like it.”
The Porsche Sportmatic lived from 1968 through 1980 but had low interest so Porsche did not introduce the next true automatic transmission until 1990 with the Tiptronic transmission. As the defunct Sportmatic.org web site noted, production of Porsche Sportmatic models was over 1,000 units per year, and just under in its later years of production.
PCarMarket is currently offering a 1973 Porsche 911T Targa Sportmatic. The bid is at $30,000 with a “Buy Now” price of $60,000. There seems to be low interest in this unique clutchless Sportmatic Porsche, but as the peanut gallery notes it may be due to the seller not providing the requisite background photos, videos and details required in today’s auctions.
1973 Porsche 911T Sportmatic for Sale: https://www.pcarmarket.com/auction/dealtank-1973-porsche-911t-targa/