Ultimate Guide to Porsche 1974 RSR Parts: What You Need to Know

The Porsche 1974 911 RSR is one of the most iconic racing cars of its era, and finding the right parts for restoration or maintenance can be challenging. This guide covers the essential components, sourcing options, and practical advice to help you get the job done without guesswork.

Understanding the 1974 Porsche 911 RSR

The 1974 RSR was Porsche's factory race car, built to compete in the FIA Group 4 and IMSA series. It featured a bored-out 2.8L or 3.0L flat-six engine, flared fenders, a ducktail rear spoiler, and lightweight construction. Because of its limited production and racing history, many parts are now rare or reproduced. Knowing the key differences from standard 911s is crucial for buying the correct components.

Key Categories of 1974 RSR Parts

Engine Components

The heart of the RSR is its high-performance engine. Common parts you may need include:

• Pistons and cylinders: Mahle pistons with Nikasil-coated cylinders were original. Today, you can find OEM-style replacements from JE or CP-Carrillo.
• Connecting rods: Upgraded to forged steel. Look for Carrillo or factory rods.
• Camshafts: The RSR used aggressive profiles. Schrick or Webcam offer modern equivalents.
• Crankshaft: A forged steel crank with oil feed modifications. Stock 911 units are not direct fit.
• Heads and valves: Larger intake and exhaust valves (50mm/46mm). Factory or aftermarket aluminum heads are available.
• Intake and fuel delivery: Mechanical fuel injection (MFI) with individual throttle bodies. Restored MFI pumps are available through specialists like Pelican Parts or Redline.

Transmission and Drivetrain

The RSR used a close-ratio 915 transmission with a limited-slip differential. Parts to consider:

• Gear sets: Often upgraded to dog-leg or straight cut. Companies like Porsche Gearbox Parts offer repro sets.
• Clutch: A heavy-duty pressure plate and sprung-hub disc. Sachs makes OEM-spec units.
• Axles: Reinforced half shafts with CV joints.
• Differential: The factory limited-slip unit is rare; Quaife and Guard Transmission offer modern alternatives.

Suspension and Chassis

The RSR had a unique suspension setup with larger torsion bars and adjustable components.

• Torsion bars: 23mm front, 27mm rear. Replacements from Sway-A-Way or Elephant Racing fit.
• Struts and shocks: Bilstein coilovers were standard. Many use KW or JRZ for track use.
• Control arms and bushings: Polyurethane or monoball bushings improve feel. Factory aluminum arms can be found used.
• Sway bars: Adjustable bars (front 22mm, rear 19mm) are available from Stomski Racing.

Braking System

Brakes were upgraded from stock with larger calipers and rotors.

• Calipers: 4-piston aluminum calipers from Brembo or Bilstein. Reproductions exist.
• Rotors: Drilled or slotted, 12.6-inch diameter. Companies like Zimmerman offer correct patterns.
• Master cylinder and booster: Tandem master cylinders are rare; rebuild kits are available.
• Brake lines: Stainless steel flex lines are recommended for safety.

Body Panels and Exterior Trim

The wide-body RSR has distinctive panels: front bumper with integrated spoiler, flared rear arches, and a ducktail rear lid.

• Front bumper: Fiberglass or steel repros from GT Racing or Treffen. Ensure correct shot-peened shape.
• Rear fenders: Steel originals are nearly impossible to find. Fiberglass panels from Vintage RSR Parts are lighter.
• Ducktail: Usually fiberglass with a metal core. Aftermarket versions from Sportin' Rick's or M&R Sales.
• Lighting: H4 headlights and Bosch fog lights. Repro sealed beams are fine.
• Badging: CIBIÉ lights and correct RSR decals available through specialty decal vendors.

Interior and Dashboard Parts

Interior was stripped for racing, but for a road conversion you may need:

• Dashboard: Original flat dash with VDO gauges. GAUGE holder for center tach. Options for repro dashes.
• Seats: Recaro race seats with one piece shell. Reproductions from OMP or Sparco.
• Steering wheel: Momo Prototipo or factory 380mm wheel.
• Carpet and headliner: Lightweight materials. Source from Autos International.

Electrical and Lighting

• Wiring harness: Often damaged. Can be custom made by companies like Roadster Tech.
• Alternator: 55-70 amp units. Bosch rebuilds are reliable.
• Ignition system: Points with CDI box. Modern 123ignition distributors eliminate points.

OEM vs. Reproduction Parts: What to Choose?

Original Porsche parts are ideal for concours-level restorations but are extremely expensive and scarce. Reproductions now offer excellent quality at lower cost. For engine internals, always use known brands (Mahle, JE, Carrillo). For body panels, good fiberglass parts save weight but may need finishing. Suspension and brakes can often be upgraded with modern equivalents that improve safety and performance without sacrificing authenticity. If you plan to drive the car, prioritize safety over originality.

Where to Find 1974 RSR Parts

• Specialty Porsche parts brands: Pelican Parts, ECS Tuning, and Rennlist are good starting points. They stock many reproduction parts and have knowledgeable staff.
• Porsche dealers: Still carry some parts via Porsche Classic program, but expect high prices.
• Forums and classifieds: Rennlist, Pelican Parts forum, and The 914 Club (for shared parts) have active classifieds.
• Swap meets and events: Porsche Parade and Luftgekühlt often have parts vendors.
• Specialist fabricators: Companies like Rothsport Racing or TRE Motorsports make custom parts.

Practical Considerations for Restoring an RSR

• Budget: A complete restoration can cost $150,000+ for parts alone; prioritize engine and brakes.
• Authenticity: If building a track car, don't worry about every detail. If aiming for FIA papers, documentation matters.
• Safety: Replace all rubber components, brake lines, and bushings. Use modern fluids and tires.
• Documentation: Keep receipts and part numbers for resale or if you ever race.

Final Recommendation

For most enthusiasts, the best approach is to use a mix of genuine Porsche parts where they affect originality (badges, interior trim) and high-quality reproduction or aftermarket parts for mechanical items. Start with a trusted parts supplier who specializes in classic 911s and can confirm fitment. Join online communities to find rare parts and get real-world advice. Focus on the safety-critical systems first—brakes, suspension, and engine—before tackling cosmetics. With careful sourcing, you can build a 1974 RSR that performs as well as it looks.