The Porsche 934/5, the inspiration for the Singer DTS Turbo

Singer’s latest design exercise, the Singer DTS Turbo, is inspired by the Porsche 934/5.  What is this legendary and rare racer?


  • Singer DTS Turbo inspired by the Porsche 934/5.
  • The Porsche 934/5 is a rare and iconic Porsche race car.
  • The Singer DTS Turbo is available in a road-legal or track version.

Singer, arguably, the most well-known “resto-mod” specialist focused on the Porsche 911, has revealed their most aggressive interpretation of the iconic sports car to date. Many Porsche fans will recognize the new Singer’s lines as very similar to those of the Porsche 934/5.  It is no coincidence, as the Porsche 934/5 inspired the Singer DTS Turbo.  This begs the question, what is the Porsche 934/5?

Porsche 934/5 side view

What is the Porsche 934/5?

The Porsche 934/5 was a combination of the Porsche 934 and 935 models, built to rule the roost in the Racing Group 4 segment of the prestigious International Motor Sports Association (IMSA). With only ten examples built in 1977, the Porsche 934/5 has the chassis and engine of the 934 with the tires, suspension, and wing of the Porsche 935.

Porsche 934-5 02

What was the Porsche 934?

The Porsche 934 was a racing version of the Porsche 911 Turbo, prepared to FIA Group 4 rules. The Group 4 racing class referred to regulations for cars in sportscar racing, GT racing, and rallying, as regulated by the FIA. The Group 4 class was replaced by Group B in 1983. Yes, that Group B racing.

Porsche 934-5 03

What was the Porsche 935?

The Porsche 935, like the Porsche 934, was also a racing version of the Porsche 911 Turbo prepared for the more lenient Group 5 rules. Group 5 was also an FIA motor racing classification that applied to four distinct categories of cars between 1966 and 1982. Group 5 regulations were the more lenient of the two.

Porsche 935
By nakhon100 – Porsche 935 Turbo K3 Kremer Racing, CC BY 2.0,

What is the history of the Porsche 934/5?

The project to build the Porsche 934/5 kicked into high gear on January 22, 1977, when racing driver Peter Gregg and his dedicated Brumos crew traveled to Germany to get parts for their next race car. Determined to build a competitive racecar for the season, Gregg and his team decided to equip the 934 with the 935’s rear wing and install a turbocharger. This power boost aimed to level the playing field against formidable opponents, including the high-performance DeKon Monzas.

Where does the name of the Porsche 934/5 come from?

The name “934/5” pays homage to the Porsche 911 Turbo’s codename, “930,” and the “4” signifies its birthright to compete in IMSA’s Group 4 racing segment. The “/5” pays homage to the Group 5 racing segment.

What is the design of the Porsche 934/5?

The design language of the Porsche 934/5 draws significant inspiration from its predecessors. The base design is a tribute to the 934 model. However, the 934/5 borrowed some aspects from the Porsche 935, specifically a large rear spoiler, expansive bodywork, and broad fenders. The enlarged bodywork was necessary to accommodate the tremendously wide rear wheels. The result is a car that, in prototype form, dominated the tracks it raced on.

The Porsche 934/5: A Detailed Look at Its Specifications

Under the Hood, The engine, like all Porsche 911s, is placed behind the rear axle and aligned longitudinally. It is a robust flat-six unit equipped with a KKK turbocharger. The single overhead camshaft (SOHC) valvetrain complements the engine, aided by a K-Jetronic mechanical fuel injection system.

The engine has a displacement of 2993cc or 182.64 cubic inches and maintains a compression ratio of 10.3:1. At 7000 rpm, it can produce an impressive 485 bhp (or 361.7 kW), translating to a specific output of 162.04 bhp per liter. With regards to torque, it can deliver 434 ft-lbs (or 588.4 Nm) at 5400 rpm.

The body and frame: The Body and frame of the 934/5 is primarily constructed of unit steel, with some parts made of fiberglass. The vehicle is a rear-wheel-drive (RWD) configuration and uses BBS Center-Lock type wheels.

Brakes: Stopping power is in the form of 16×10.5 inch front and 16×12.5 inch rear brakes, with steering through a rack and pinion mechanism.

Dimensions and Measurements: The car has a wheelbase of 89.4 inches (or 2271 mm). The front track measures 55.2 inches (or 1402 mm), while the rear track comes in at 56.0 inches (or 1422 mm). The overall length, width, and height are 162.5 inches (4128 mm), 65.0 inches (1651 mm), and 52.0 inches (1321 mm), respectively.

Transmission: The 934/5 features a 5-speed manual transmission with a single plate clutch. It has gear ratios of 3.18:1, 1.83:1, 1.26:1, 0.925:1, and 0.724:1, with a final drive of 4.43:1.

Performance: In terms of performance, the car can reach a top speed of approximately 178 mph (or 286.5 km/h). It can sprint from 0 to 60 mph in roughly 5.6 seconds and 0 to 100 mph in about 12 seconds. The 0 – 1/4 mile time is approximately 13.2 seconds.

The fuel capacity is 31.68 gallons (or 120 liters), reflecting the vehicle’s design goals of competing in longer endurance events.

Introducing the Singer Dynamics & Lightweighting Study

Singer, a California-based specialist of air-cooled 911s, recently developed the Dynamics & Lightweighting Study (DLS), with the turbocharging feature, the DLS Turbo, modeled after the legendary Porsche 934/5. 

Singer DLT Turbo 01

What is the Singer DLS Turbo?

The DLS Turbo is an homage to the legendary 934/5 endurance racers of the 1970s and is available in a track and road version. The DLS Turbo is a symbol that connects the past and the present in racing DNA.

Singer DLT Turbo 02

What is the Singer DLS Turbo based on?

As with all Singer builds, the Singer DLS Turbo is based on the Porsche 964, built between 1989 and 1994. Each Singer is stripped down to the metal, perfected, and re-engineered with the best, most modern components and materials.

Singer DLT Turbo 03

Is the Singer DLS Turbo made of carbon fiber?

While the Singer retains the Body of its donor, it is extensively modified with carbon fiber bodywork to reduce weight and enhance the overall stiffness of the car.

Singer DLT 04

What is the Singer DLS Turbo powered by?

The heart of the Singer DLT Turbo is sourced from the donor 964. After being stripped down to the block, the engine is meticulously restored with high-performance components and modifications for optimized performance. The result is a unique 3.8L, 4-valves per-cylinder flat-six engine, equipped with twin turbochargers, electric wastegates, air-to-water intercooler, and a horizontally mounted, electrically powered fan.  

Built by Porsche Motorsport to Singer’s specifications, the engine powering the DLS Turbo can deliver over 700 HP at over 9000 rpm, guaranteeing the driver and their passengers an amazing ride.

Singer DLT Turbo 05

What will the Singer DLS Turbo cost?

Every Singer is built to the owner’s exact specifications and can easily exceed $1 million. The Singer DLT Turbo will be offered in limited numbers. As a result, it can easily exceed that amount.  

In contrast, 10 Porsche 934/5s were produced and don’t come up for sale often. In the last five years, they have ranged in price from a low of $885,000 to a high of $1.2 million. Regardless of the price, you can expect that like the Porsche 934/5, the Singer DLT Turbo a sight to behold, both on track and on the road.


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