Exhaust muffler clamp. Porsche 997 GT3 / 991 GT3 / Carrera GT

Front muffler clamp (OE part reference 997.111.336.90) — used to secure the front/centre muffler sections on 911 GT3 / GT3 RS and compatible Porsche 997 / 991 fitments. Built to the factory dimensions for a leak-free connection and correct exhaust alignment.
Price is Each

Fits:
Porsche Carrera GT 2004 - 2006
Porsche 997 GT3 2007 - 2009
Porsche 997 GT3 / GT3 RS / GT3 RS 4.0 2010-11
Porsche 991 GT3 / GT3 RS 2014-18
Porsche 991 R 2016

Diagram ref no 5

Why Replace Your Exhaust Clamp

• Restore a perfect, leak-free seal
• Over time, exhaust clamps can deform, corrode, or lose their clamping strength. Replacing the clamp ensures a secure joint between muffler sections, preventing exhaust leaks, restoring proper back pressure, and maintaining optimal engine performance.
• Eliminate rattles and vibration noise
• Worn or loose clamps are a common cause of rattles, buzzing, or vibration noises from the rear underside of 997 and 991 models. Installing a new clamp is often one of the quickest and most cost-effective ways to eliminate these irritating sounds.
• Factory specifications fitment for performance models

Common Issues and Failure Modes

• Corrosion and rust
• Exhaust clamps and fasteners are exposed to heat, moisture, and road salt. Over time, this can lead to corrosion or seizure, reducing clamping force and risking exhaust leaks.
• Clamp fatigue or deformation
• Repeated heat cycles and vibration can cause the clamp sleeve or bolt to distort, leading to a loose connection and exhaust blow-by.
• Incorrect fitment or short sleeves
• Noise from over-tightening
• Applying excessive clamping force can alter vibration characteristics and introduce new noises. Always follow correct installation torque and alignment procedures.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99711133690

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