The turbo manifold supports the turbine and withstands temperatures of up to 900 °C: it is the most heavily stressed part of a turbocharged engine. A free-flowing design builds boost earlier; a suitable flange allows you to install a larger turbine than the original one and therefore target 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 for better designs, but requires properly designed supports: a cantilevered turbine will eventually open a weld.