What are the stage 1, stage 2, stage 3, stage 4 and stage 5 performance upgrades for the classic Mini a-series engine?
There are 5 stages to improving the performance of an a-series engine. The first stage usually comes in the form of a kit. In addition to this kit it is usually a good idea to replace worn components such as spark plugs, HT leads, distributor, coil, etc. Then after you have the stage 1 kit installed it’s just a matter of upgrading various components further in order to advance a stage and increase your engine’s performance. A summary of the stages: Stage 1: K&N air filter, needle replacement, inlet manifold, exhaust manifold and exhaust system (usually RC40), gasket and exhaust mounting kit. Stage 2: Uprated stage 1 parts with a modified cyclinder head, replacement rockers, head gasket, optional uprated camshaft. Stage 3: Uprated stage 2 parts plus bigger inlet and optional bigger exhaust valves. Stage 4: Uprated stage 3 parts plus bigger inlet and exhaust valves. Stage 5: Uprated stage 4 with extra modifications.
