Porsche 911 997 GT3 / GT3RS Rear Silencer

In 2026, the Porsche 911 (997) GT3 and GT3 RS rear silencer (the center muffler) is a legendary component sought after for both restoration and as a popular “center muffler bypass” upgrade for standard Carrera models.

There is a critical distinction between the Stainless Steel version found on the standard GT3 and the ultra-lightweight Titanium version found on the 997.1 RS and 997.2 RS.

1. Material & Version Differences

The 997 GT3 exhaust layout is a “3-muffler” system: two side mufflers and one large center silencer.

• 997.1 / 997.2 GT3 (Stainless Steel): * Durable, heavy, and provides a deep, mechanical howl.

  • Part Number: 997-111-027-92 (Standard version).

• 997.1 / 997.2 GT3 RS (Titanium): * Known for its blue/purple heat tint and “sand-blasted” finish.

  • Saves approximately $20\text{ lbs}$ ($9\text{ kg}$) over the rear axle.

  • Part Number: 997-111-027-90 (Titanium version).

3. The “Center Muffler Bypass” (The 2026 Trend)

Many owners are choosing to remove this heavy center silencer entirely and replace it with a Center Muffler Bypass (CMB).

• Why? It reduces weight, improves engine cooling, and unlocks the famous high-pitched “GT3 scream.”

• Top Brands: SharkWerks ($1,100), Soul Performance ($1,600), and Akrapovič (Titanium, $3,500).

• Benefit: You can keep your side mufflers and factory “Sport” valve functionality while losing the bulk of the rear silencer.

4. Maintenance Warning: Cracking

In 2026, original 997 GT3 center silencers (especially the Titanium ones) are reaching an age where the internal baffles can break loose or the external welds can hairline crack due to heat cycles.

• The Symptom: A metallic “rattle” at $3,000\text{–}4,000$ RPM.

• The Fix: Titanium units require a specialist welder with a vacuum chamber to repair correctly. Stainless units can be tig-welded by most high-end exhaust shops.

5. Installation Tip

• Tailpipes: The GT3 rear silencer has a central exit for the dual tips. If you are buying a used silencer, ensure it includes the center mounting bracket and the exhaust clamps. These clamps are often “one-time use” and usually need to be replaced after being torqued for 15+ years.