Forged low silicone alloy CP Pistons are used. Low silicone alumium is tougher and can take turbo induced abuse better. The engine runs a fairly high for a forced induction 10:1 compression ratio for good off boost throttle response. The pistons use the stock 93mm bore.
The thick wall piston pins are good for the high loads that a turbocharged engine can generate. Flexing piston pins can cause failure of the small end rod bushings which can result in rod or piston pin boss breakage. The taper on the end of the outside diameter of the piston pin helps keep the wire retainer in place.The pistons are conventional in design using a full skirt. They use narrow low tension rings with a pressure equalization groove between the top and second ring for improved ring seal at high rpm. The piston skirts are molly coated for lower friction and longer life.The piston rings use a chrome top ring and a nitrided iron second ring. They are 1.2 mm low tension rings. The oil ring is a conventional two rail design.
