- The piston is 87mm, which happens to be 1mm bigger compared to conventional 86mm, and the fabric is light-weight and strong A4032 solid aluminum alloy. The required clearance of 0.In 1995, Nissan revamped the RB25 series and made quite a few variations. The turbo was made a bit larger (45V2), though stated horsepower stayed a similar – a probab