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I5 Cast Inlet Plenum [Mk2 Focus RS/ST]

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.

The I5 cast inlet plenum is supplied in an "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).

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

Customer Reviews
4.8 Based on 22 Reviews
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Filter Reviews:
    Stuart R.
    United Kingdom United Kingdom

    Usual mountune quality thanks

    Faultless no complaints here thanks very much

    mountune I5 Cast Inlet Plenum [Mk2 Focus RS/ST] Review
    United Kingdom United Kingdom

    I5 Cast Inlet Plenum

    Relatively straight forward installation apart from the push fit Vac Pipe which is an extremely tight fit compared to the original. Vastly improves the engine bay appearance although haven’t test driven yet.

    Tim H.
    Australia Australia

    Tim H

    Delivery to Aus was quick. Purchased mainly for piece of mind as I didn't want to plastic one to let go as others have. The only issue is the Vacuum hose fitting is overly tight to push the fitting all the way in. Overall well worth it