Porsche 911 Backdate

Porsche 911 Backdate

Coupé, 1977


  • tribute to the legendary early 1970s 911 S/T
  • Full coilover Bilstein RSR suspension
  • The Porsche Auction in partnership with Air|Water

1977 Porsche 911 S Coupe Backdate Turbo S/T

Built by Matthew Mariani of the R Institute as a tribute to the legendary early 1970s 911 S/T – Stitch-welded, strengthened body finished in Nardo Grey with custom, all-metal hand-shaped fender flares and aerodynamic enhancements weighing 2250 pounds – Sports-purpose interior with red leather seats from GTS Classics, Repa belts, Momo Prototipo steering wheel, body-color dash and roll bar, and a 10k rpm tachometer – Rebuilt and highly modified 425 horsepower 3.3-liter 911 Turbo engine mated to a custom close ratio four-speed 930 transmission
Full coilover Bilstein RSR suspension with components from Elephant Racing and Tarret Engineering – Custom components include 9 and 11×15 inch Fuchs-style wheels, Cibié hood lights, Brembo brakes, Lexan windows, a custom steel ducktail, and 911 R-style taillights

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The vehicle in detail

Chassis No. 9117200156
Engine No. 6890582

A precursor to the legendary 911 Carrera RS 2.7 of 1973, Porsche offered a lesser-known lightweight road racer with equipment number “M471” – more commonly referred to by Porsche enthusiasts as the 911 “S/T.” The race-ready 911 effectively combined the running gear of the sporting 911 S with the reduced interior equipment of the base 911 T – hence S/T – intended for competition in FIA Group 3 racing. Refined over a period of about three years (1970–1972), S/T came to define a very limited number of 911s modified with various racing components and powered by 2.2 to 2.5-liter flat-sixes, with most sharing in common widened rear fender flares to accommodate their eight to nine-inch-wide rear tires.

While true production figures are estimated to be anywhere from 33 to as many as 62 examples, what is known is that the 911 S/T has inspired many Porsche hot-rodders with its lightweight modifications and distinctive aesthetics. Beginning life as a 1977 911 S, this one-of-a-kind Porsche underwent a comprehensive transformation to “Turbo S/T” specifications by Matt Mariani of The R Institute. Extensive work on this bespoke 911 involved stitch welding the entire body and leading all the seams, as well as hand-forming the flared rear quarters and fenders out of steel. A single piece of 20-gauge steel (weighing a mere 11.5 pounds) makes up the large ducktail spoiler, which is flanked by Martini Targa Florio RSR-inspired spoilers formed in aluminum. Improvements to the running gear involved fitting a turbocharged 3.3-liter flat-six sourced from a 1979 930 Turbo and modified with a Patrick Motorsports-upgraded K27-7200 turbo, ARP head studs, coated race bearings, CP-Carillo rods, Mahle pistons, 964 cams, ignition by Classic Retrofit, and more. This engine is mated to a one-inch-shortened 930 four-speed manual transaxle with revised close-ratio gearing, a lightweight Sachs Racing pressure plate, and a strengthened bell housing. A claimed 425 horsepower and over 430 lb-ft of torque is fed through a factory limited-slip differential to the 11-inch-wide rear Fuchs wheels, propelling the scant 2,250-pound 911 to a remarkable 170 mile-per-hour top speed. Mitigating this visceral power are a host of chassis improvements encompassing a Bilstein RSR coil-over suspension with Elephant Racing and Tarret Engineering components at all four corners, 906 front and Brembo rear brakes, and a set of Michelin TB tires. The result is a truly exhilarating driving experience to match its ultra-aggressive appearance.

Completed in August of 2023, this exciting Turbo S/T is offered with a comprehensive digital file of invoices and restoration images documenting its extensive multi-year transformation. With its exceptional performance and attractive race-inspired looks, this fantastic tribute to the original 911 S/T would make a head-turning entry into any number of tours and rallies across the country.

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Year of construction: 1977
Model: 911 Backdate
VIN: 9117200156
Body: Coupé
Series: 911 Backdate/Modified
Cylinder capacity: - Liter
Steering: left
Transmission: Manual
Drive: Rear drive
Fuel: Gasoline
Interior color: Black
Interior material: Leather
Exterior color: Grey
New / used: Used car
Ready to drive: yes
Car location: USUnited States

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