The 11.8:1 compression will provide you with more acceleration than kits with 11.3:1 compression. For track use we recommend more aggressive cam (maximum valve lift (tdc) of 2.1 mm) . Piston's has very deep pockets for use with sport valves. These are 107 mm in size so are slip fit and do not require modifications. This kit is ideal for track use but can also be used on the street, it will add 35+ hp (depending on your additional modifications). Mahle pistons are forged for substantially higher and more uniform strength over pistons that are cast. Mahle cylinders are manufactured from st52 steel which has extremely high thermal resistance, they are nikasil coated which reduces wear and friction. We also have t...(choose a part on the right to read more)