Premium JMTC Billet Compressor Turbine Wheels
Billet compressor wheels are machined from a solid block of billet aluminum. Most compressor wheels are made from cast material, meaning the metal is heated to the melting point and pored into a mold. This can lead to imperfections in the materiel such as casting voids or week spots where the materiel didn't bond. Sometimes there might be slight differences from one side of the molded component to the other. Most of the casting differences do not effect the operation of the turbine but they can effect the efficiency in a minute way. The cast process does work well enough for a turbocharger that is used for normal street applications. However if you are running boost levels above 18 to 19psi they can flex, bend and in some cases come apart altogether. (Click on the following link for the complete article.) http://new.minimania.com/MINI_Cooper_Turbo_Kit