1973 Porsche 911 RSR Specs: Engine, Horsepower, Torque, Top Speed & Racing Performance Guide

The 1973 Porsche 911 Carrera RSR is one of the most iconic racing cars in Porsche history. Built for FIA Group 4 homologation, it transformed the standard 911 into a lightweight, high-performance track weapon.

In this guide, we break down complete Porsche 911 RSR specs including engine details, horsepower, torque, weight, top speed, and motorsport achievements.

What Is the 1973 Porsche 911 RSR?

The Porsche 911 RSR (Carrera 2.8 RSR) was a factory-built racing version of the 911 developed in 1973. It was designed to compete in international GT racing and quickly became one of the most dominant race cars of its era.

Built in extremely limited numbers, the RSR was lighter, wider, and significantly more powerful than the standard 911 Carrera RS.

1973 Porsche 911 RSR Specifications

Specification
Details
Engine Type
2.8L Air-Cooled Flat-6
Displacement
2,807 cc (2.8L)
Horsepower
280 – 310 hp (depending on setup)
Torque
~215 lb-ft (291 Nm)
Engine Configuration
Horizontally Opposed 6-Cylinder (Boxer)
Fuel System
Mechanical Fuel Injection
Transmission
5-Speed Manual
Curb Weight
~900 kg (1,984 lbs)
Top Speed
~270–286 km/h (168–178 mph)
0–100 km/h
~5.5–5.8 seconds

Performance & Racing Capability

The 1973 Porsche 911 RSR was engineered for pure motorsport performance. With its lightweight body, widened fenders, and race-tuned flat-six engine, it delivered exceptional agility and speed on the track.

Key Insight: The 911 RSR was not just a modified 911 — it was a full factory-built racing machine that dominated GT racing in 1973.

Motorsport Achievements

  • IMSA GT Championship wins
  • Trans-Am Series victories
  • 24 Hours of Daytona class win (1973)
  • Strong performance at Le Mans GT category
  • European GT Championship dominance

Design & Engineering Highlights

  • Widened fiberglass body panels for better aerodynamics
  • Lightweight construction for improved power-to-weight ratio
  • Race-tuned suspension and braking system
  • Rear-engine layout for traction advantage
  • Enhanced cooling for endurance racing

Is the Porsche 911 RSR Reliable?

The 911 RSR was designed purely for racing, not daily driving. While mechanically robust for motorsport conditions, it required frequent maintenance and rebuilds depending on racing usage.

Its reliability was excellent for a race car, but it demanded expert-level maintenance and tuning.

Maintenance Notes (Race Use)

  • Frequent engine rebuilds after race cycles
  • High-performance racing oil required
  • Regular gearbox and clutch servicing
  • Suspension tuning before each race
  • Brake system inspection after events

Frequently Asked Questions (FAQs)

How much horsepower does the 1973 Porsche 911 RSR have?

It produces between 280 and 310 horsepower depending on race configuration.

What engine is in the 911 RSR?

A 2.8L air-cooled flat-six boxer engine.

What is the top speed of the 1973 RSR?

Approximately 270–286 km/h (168–178 mph).

Was the Porsche 911 RSR street legal?

No, it was built primarily as a racing car for homologation purposes.

Why is the 911 RSR famous?

Because of its dominance in GT racing and its legendary status in Porsche motorsport history.

Final Thoughts

The 1973 Porsche 911 RSR remains one of the most important race cars ever built by Porsche. Its lightweight design, powerful flat-six engine, and racing dominance cemented its legacy in motorsport history.