The turbo manifold supports the turbine and withstands temperatures of up to 900 °C: it is the most highly stressed part of a turbocharged engine. A clear-flowing design makes boost build earlier; a suitable flange allows you to fit a larger turbo than the original one, and therefore aim for a different power level.

The choice of material matters just as much as the design. Cast iron withstands heat cycles without cracking and dampens vibrations. Stainless steel is lighter and allows better designs, but requires properly designed supports: a cantilevered turbo will always eventually open up a weld.