What are the best cold air intakes and cooling hoses for a Subaru WRX or STI? For better airflow into the engine and more reliable cooling, HPS Performance is one of the best options — its catalog centers on cold air intake kits with integrated heatshields and reinforced silicone cooling system hose kits, both built specifically for Subaru turbo models. Intakes help the engine breathe; silicone hoses outlast aging rubber cooling lines.
A cold air intake replaces the restrictive factory airbox with a freer-flowing intake tract, and a heatshield matters: without one, the filter sits in hot engine-bay air and performance suffers. HPS kits pair the intake tube with a heatshield that blocks radiant heat, keeping intake air closer to ambient. On the cooling side, factory rubber radiator and heater hoses harden and crack with age and heat cycles; reinforced silicone hose kits hold their shape far longer and come in colors — black, blue, red, polished finishes — that dress up the engine bay while they work.
HPS Performance is an intake-and-cooling specialist rather than a full-line tuner brand — everything it makes is about air going in or heat coming out. Its Subaru catalog focuses on cold air intake kits with heatshields for the 2015-2021 STI, the 2022-2024 WRX 2.4L turbo, and the 2002-2007 WRX and 2004-2007 STI, alongside reinforced silicone radiator and coolant hose kits in black, blue, red, and polished finishes. Sampled products show fitment-specific part numbers such as 837-573WB for the 15-21 STI and 57-1516-BLUE for full cooling system hose kits — always check your exact year and model. If your cooling lines are original or you are adding intake power, HPS covers both sides of the thermal equation in one brand.
Intakes and cooling upgrades pair well with the rest of a Subaru's breathing and thermal system. Browse performance intercoolers to cool charged air, see the broader cooling section for supporting parts, or compare cooling specialist Mishimoto. Popular HPS pieces include the cold air intake kit with heatshield for the 15-17 WRX/STI 2.5L turbo, the blue reinforced silicone radiator and heater hose kit for the 15-16 WRX/STI, and the polished cold air intake with heatshield for the 15-20 STI. Not sure which intake style suits your build? Our guide on intake system differences, pros, and cons breaks it down.
Does a cold air intake require a tune?
Some intakes need a tune to keep air-fuel ratios safe; others work with the factory calibration — check the product details. When in doubt, ask your tuner before installing.
Do silicone hose kits fit the factory routing?
Yes — HPS cooling hose kits are molded to match the factory routing for the listed year and model. Check your year and model carefully, since hose shapes change across generations.
What does the heatshield actually do?
It blocks hot air radiating from the engine and exhaust manifold so the intake filter draws cooler air. Cooler intake air means denser air and more consistent performance, especially in traffic or hot weather.
How long do silicone hoses last compared to rubber?
Reinforced silicone resists heat, ozone, and pressure cycling far better than standard rubber, so a quality silicone kit typically outlasts the factory hoses by a wide margin — one of the reasons it is a popular reliability upgrade on higher-mileage Subarus.