I5 Cast Inlet Plenum

In 2010, the mountune's highly-skilled engineers identified an obvious performance and aesthetical improvement to all I5 engines through the creation of an I5 cast inlet plenum.

Extensive in-house CAD and CFD work (by the same team responsible for producing mountune's BTCC, WTCC, WRC and Rallycross inlets) allowed an improvement to be made - particularly around the port entrance to each inlet, as well as to increase the volume of the plenum itself to a more appropriate size for the 2.5-litre engine.

The mountune I5 cast inlet plenum has fast become the market-leader in the I5 cast inlet plenum sector with good reason; proven performance benefits across a multitude of power outputs, durable construction, OE packaging for ease of installation on mk2 Focus RS, mk2 Focus ST and various Volvo models - all combined with the assurance of buying from the best in the business and a name you can trust - mountune.

The I5 cast inlet plenum is supplied in two finishes, natural silver and "RS500" black, and comes supplied with the required hardware for installation. Fitting takes less than 30 minutes on a mk2 Focus RS and approximately 60 minutes on a mk2 Focus ST (recommended removal of OE induction assembly). Colour fitting instructions are supplied.

Substantial performance gains can be expected on all I5 engines. Some example graphs can be seen here showing the typical improvement to a mountune mk2 Focus RS MP350, and also a mountune mk2 Focus ST MP260.

Output improvements will vary on non-mountune upgraded vehicles, dependent on specification of tune, calibration and boost level being run.