Porsche 934/5
The Porsche 934/5 is a racing car that was designed as a hybrid of the Porsche 934 and Porsche 935 to compete in Group 4 of the IMSA.
History
The Porsche 934/5 was assembled from 10 samples of Porsche 934 and Porsche 935, by incorporating the Chassis and engine of the 934 with the wheels, tires and rear wing configuration of the 935, creating the new 934/5. The goal for the new design was to compete in the Group 4 racing competition of the IMSA in 1977. On January 22, 1977, Peter Gregg and Brumos crew team flew to Germany, in order to acquire the resources necessary for this new car under construction to be assembled. Gregg and his team decided to fit the 934 with the 935's rear wing and to add a turbocharger, so that they could compete with the other racing cars, such as the more powerful DeKon Monzas. The name has been carefully selected and origins from the Porsche 911 Turbo. The "4" in the name comes from the fact that the 934/5 was built to compete in the Group 4 of the IMSA.Design
For the design of the Porsche 934/5, Porsche was strongly inspired by its previous models. The basis for design has been influenced by the Porsche 934. However, Peter Gregg and his team made the decision to fit the newly designed car with the large rear spoiler, the widened body work and the big fenders from the composition of the Porsche 935. The widened body work was required for the large rear wheels to fit. The result of the mixture between the 934 and 935 is a prototype-looking car, ready to dominate the racing tracks, which it was designed for.Motorsport
The Porsche 934/5 did not participate in many races, since the IMSA banned the 934/5 before it could compete in its first race. Due to this ban, the designers decided to enroll their machine in the rival SCAA Trans Am Series, in which the Porsche participated and won 6 out of the 8 races. These victories would mean that the 934/5 would be the 1977 champion, however, due to a formal protest against the 934/5 by Ludwig Heimrath, the officials declared Ludwig and his Porsche 934 champions of 1977.Specifications
| Engine | Flat-six engine |
| Position | Rear, Longitudinal |
| Aspiration | KKK Turbocharger |
| Valvetrain | SOHC |
| Fuel Feed | K-Jetronic Mechanical Injection |
| Displacement | 2993cc / 182.64 in³ |
| Compression | 10.3:1 |
| Power | 361.7 kW / 485 bhp @ 7000 rpm |
| Specific Output | 162.04 bhp per litre |
| Torque | 588.4 Nm / 434 ft lbs @ 5400 rpm |
| Redline | 8500 |
| Body/Frame | Unit Steel with some fiberglass |
| Driven Wheels | Rear Engine / RWD |
| Wheel Type | BBS Center-Lock |
| Front Brakes | F 40.6 x 26.7 cm / 16 x 10.5 in |
| Rear Brakes | R 40.6 x 31.8 cm / 16 x 12.5 in |
| Steering | Rack and pinion |
| Wheel Base | 2271 mm / 89.4 in |
| Front Track | 1402 mm / 55.2 in |
| Rear Track | 1422 mm / 56.0 in |
| Length | 4128 mm / 162.5 in |
| Width | 1651 mm / 65.0 in |
| Height | 1321 mm / 52.0 in |
| Transmission | 5-Speed Manual |
| Tran Clutch | Single Plate |
| Gear Ratios | 3.18:1, 1.83:1, 1.26:1, 0.925:1, 0.724:1 |
| Final Drive | 4.43:1 |
| Top Speed | ~286.5 km/h / 178.0 mph |
| 0 - 60 mph | ~5.6 seconds |
| 0 - 100 mph | ~12.0 seconds |
| 0 - 1/4 mile | ~13.2 seconds |
| Fuel Capacity | 120 litres or 31.68 gal. |
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The creation of this car has been made possible by a change in rules. In the 1977, the IMSA had implemented a rule that allowed Porsche racers to add a single turbocharger to their cars, to increase their competitiveness versus the rival race cars which featured more horsepowers. As a result, a 3 Liter Flat-six engine, fitted with a single KKK turbocharger, that could generate 590 bhp, and go 0 to 60 in 5.6 seconds was created for the 934/5. The car also sported huge rear wheels, which made it a tough job to drive the car correctly, especially at high speeds.
Auctions
Due to the fact that Porsche only built 10 of the 934/5, the price to pay in order to purchase one can vary.These prices are established at auctions. For the last known sales figures of the 934/5, the Gooding Amelia Auction has auctioned one of the ten models for $1,375,000.