CP Piston Volkswagen GTI/Jetta - Bore (83mm) - Pin (21mm) - Dome (-8.5cc) - CR (9.5:1) - SINGLE

CP Pistons is known for making strong internal engine components, and this forged piston for your Volkswagen GTI or Jetta is a prime example. If you're rebuilding the top end of your engine, this single piston is built to handle the demands of performance driving. It features an 83mm bore, a 21mm pin size, and a -8.5cc dome volume, which results in a 9.5:1 compression ratio. This specific compression ratio is a popular choice for many performance builds, offering a good balance between power and reliability.

This piston is forged, meaning it starts as a solid block of aluminum that's heated and hammered into shape. This process creates a much stronger and more durable part than cast pistons, making it ideal for engines that see higher cylinder pressures or are subjected to more aggressive tuning. The -8.5cc dome is designed to work with specific cylinder head volumes to achieve the target 9.5:1 compression ratio, which is a notable change from stock and can contribute to improved throttle response and overall power output when paired with appropriate tuning.

When undertaking an engine rebuild, it's important to ensure all components are compatible. This piston is sold individually, so you'll need to order the correct quantity for your engine. Always refer to the manufacturer's installation instructions for proper fitment and assembly procedures.