Intercooler Kits

An intercooler cools the air a turbocharger or supercharger has compressed and heated, so the engine takes in denser air. An upgrade is chosen by how much it replaces, the size of the core, and what it takes to fit.

Replacement core or full kit

The simplest upgrade is a larger core in the factory position that keeps the factory piping. HKS's R type intercooler for the FL5 Civic Type R is one: its core is 695 x 178 x 100 mm against the factory 639 x 158 x 64 mm, with 22.4% more frontal area, and it fits the stock pipes. A full kit changes the intercooler piping too. For the Lancer Evolution X, HKS sells its 525 x 304 x 103 mm core (factory: 490 x 292 x 65 mm) either with 70 mm piping or as a version for the factory 60 mm pipes. Larger pipes suit more boost and power; the stock-pipe version is simpler to fit.

Reading core sizes

Japanese makers give core dimensions in millimetres, but not always in the same order. GReddy lists its Spec LS core for the R33 Skyline as H184/L600/W66: 184 mm tall, 600 mm across the car and 66 mm thick. Frontal area decides how much air passes through; thickness adds cooling but also adds resistance to that air. A thick core in front of the radiator can call for radiator work as well, and the HKS Evo X core is paired with a radiator upgrade for sport driving; see radiators.

Pressure loss and fitting

Every core costs some boost pressure as air passes through it, and good designs keep that loss low while still cooling; GReddy's Spec LS uses straight inner fins for low pressure loss. Front-mount kits often need the bumper or the structure behind it modified: the GReddy R33 kit needs bumper modification, and the HKS Evo X core needs the headlamp support panel, a hose and an air-conditioning pipe modified. The FL5 core needs an air guide inside the bumper altered and a bracket ground for the piping. Check what a kit needs before ordering, and allow for fitting time.

A blow-off valve is a common companion part, and GReddy sells its Spec LS with one as a set. The cooling and forced induction guides cover the rest of the system.