CP pistons are the best on the market. We use them in all our Super Coooper engine builds. Offered with 8.3 to 1 compression ratio (stock MINI ratio), 1mm, 1.2mm, 2.8mm ring package and in standard, 0.5mm and 1.0mm over bore sizes. They are forged, so they'll handle any amount of boost you can throw at them but lightweight so all that power gets to the ground. Sold in sets of 4. Each set is custom made, please allow 3-4 weeks for delivery

Link: R53 MINI Engine Forged Piston Set by CP Pistons