Mahle MS Piston Set Subaru WRX STi 2.5L 99.75mm Bore 79mm Stroke 130.4mm Rod 23mm Pin -22cc 8.5 CR Set of 4

Subaru WRX 2.5L STI/Forester/Legacy, Bore 99.75mm, Stroke 79.0mm, Rod Length 130.5mm, Dish -19.3cc, 401 Grams Advertised Weight, Set of 4 Pistons and Rings Included.

Mahle pistons were designed as a completely finished drop in forged piston assembly. Other than filling the included performance piston ring set, everything is done for you. Mahle has over 80 plus years of piston manufacturing making pistons from OEM to formula 1 racing. Mahle uses only the best technology to make these pistons. Mahle pistons come standard with anti-friction skirt coating for reduced drag. Forged from 4032 low expansion aluminum alloy for high strength and reduced piston to wall clearance. Forced Pin Oiler is used for increased wrist pin lubrication. Pin bores are CNC precision-machined. 23mm High-Quality Steel Wrist Pin (123g), Performance 1.0, 1.0, 2.0mm performance ring set, steel nitrided top ring, and Race Proven Round Wire Locks are included.

Compression Ratio with 56cc Heads 8.5:1.