Audi RS4 2.7 V6 BI-Turbo AZR ASJ AZF 8.0:1 82mm Wossner Forged Pistons Set. Compression Ratio: 8.0:1. Wössner are regarded by Europe's leading motor sport engine builders as being the piston of choice when building an engine not only to perform, but to withstand the stresses and duress's of competition life. Wössner pistons feature a unique PTFE coating on the skirts and a grade of 4032 Alloy (T6) which allows the engine builder to run a closer piston to bore tolerance then he might do on another make of piston.This helps remove the slapping noise during cold start, common place among engines running forged pistons due to larger then OE bore clearances. The crowns of the pistons are also polished to better resist detonation on a high performance engine. Polishing allows a more even spread of heat inside the chamber which will help prevent "hot spots" on piston crowns. Price includes all piston rings and gudgeon pins. Image is a Stock image. Any Items That Are Out Of Stock Or have Extended Lead Times, May Take Slightly Longer Than Normal. This item is in the category "Vehicle Parts & Accessories\Car Tuning & Styling\Engine, Tuning & Chips\Other Engine Tuning". The seller is "shopbhp" and is located in this country: GB. This item can be shipped worldwide.