AWE S-FLO Carbon Intake Review: Audi RS3 & TT RS 2.5T

The Audi RS3 and Mk3 TT RS share one of the most charismatic engines ever bolted to a compact chassis: the 2.5L TFSI turbocharged inline-five. On the 8V RS3 that motor makes 400 hp and 354 lb-ft in US trim, and it breathes through a restrictive factory airbox that leaves both power and sound on the table. The AWE S-FLO Carbon Fiber Intake is the aftermarket's answer — a modular, 2x2 carbon fiber intake suite that AWE Tuning dyno-verified at +17 wheel horsepower and +6 lb-ft of torque in its full Closed configuration. In this review we break down all three S-FLO configurations (Closed, Open, and Shortie), how they fit the 2017-2020 RS3 8V and 2018-2022 TT RS 2.5T, and where a simple aFe drop-in filter makes more sense.

Why the 2.5T RS3 Wants a Better Intake

The EA855 evo 2.5L five-cylinder is turbocharged and airflow-hungry, and the factory airbox is a compromise built for noise regulations and cost, not maximum flow. The stock inlet snorkel and paper element choke top-end breathing and trap heat against the firewall on repeated pulls. Feeding the turbo cooler, less-restricted air is one of the highest value-per-dollar upgrades on the platform — especially once you add a tune, downpipe, or bigger intercooler. At NLP Performance in Tampa, FL, the RS3 and TT RS intake is one of the first bolt-ons our five-cylinder customers ask about, precisely because it improves power, throttle response, and that unmistakable warble all at once.

AWE S-FLO Closed Carbon Intake: The Full-Power Pick

The AWE S-FLO Closed Carbon Intake System is the flagship configuration and our top recommendation. It combines every component of the S-FLO suite — the oversized S-FLO filter and 4.5″ carbon inlet elbow — and adds a bespoke enclosed carbon air box that spans the entire width of the grille to collect ram air from the front of the car. AWE Tuning dyno-tested it at 17 hp and 6 lb-ft at the wheels, and because it is fully enclosed in 2x2 carbon fiber, heat soak stays subdued during hard driving while the larger air-box volume ensures the 2.5T never runs short of cold air. It is also engineered to handle any higher-than-stock boost level you throw at it, which is why it pairs so well with a Stage 1 or Stage 2 tune.

AWE S-FLO Open Carbon Intake: Sound Meets Power

The AWE S-FLO Open Carbon Intake System uses the same oversized S-FLO filter and 4.5″ carbon inlet tube as the Closed kit, but leaves the filter exposed to the engine bay instead of enclosing it. The result is nearly the same peak airflow with a louder, more theatrical induction and turbo whoosh — the sound many five-cylinder owners are chasing. It is the middle child of the range at around $945, and AWE lists fitment for 2017-2020 and 2022-2024 Audi RS3 plus 2018-2022 TT RS, making it the broadest-fitment configuration of the three. If you want to hear the 2.5T work and still capture strong gains, the Open is the sweet spot.

AWE S-FLO Shortie Carbon Intake: The Modular Entry Point

The AWE S-FLO Shortie Carbon Intake is the most affordable way into the S-FLO suite at around $605, and it is designed to be upgraded later. It replaces the factory airbox with a massive S-FLO filter that carries a 30% increase in filter surface area, joined to a 4.5″ carbon elbow and planted with a bespoke CNC laser-cut stainless steel support bracket. AWE calls it "the perfect configuration for drivers looking to uncork beloved turbo noises," and the modular design means you can start here and evolve to the full Open or Closed system down the road. Note that AWE labels the 4.5″ S-FLO suite as intended for racing use, and 2019-and-newer cars require the separate DV Adapter Kit.

The Budget Alternative: aFe MagnumFLOW Drop-In Filter

If your budget is closer to $100 than $1,000, an aFe MagnumFLOW OE-replacement drop-in filter is the sensible starting point. The Pro 5R uses five layers of pre-oiled cotton gauze for maximum flow, while the Pro DRY S uses three layers of oil-free synthetic media that never needs oiling — both drop straight into the factory RS3 airbox and fit 2017-2023 cars. A drop-in filter won't reshape the intake tract or add the S-FLO's 17 whp, but it flows more than a clogged paper element, is washable and reusable, and is a smart maintenance upgrade while you save for a full S-FLO system.

AWE S-FLO Configurations Compared

All three S-FLO configurations share the same core S-FLO filter and 4.5″ carbon inlet, so the decision comes down to how much power, sound, and heat management you want — and your budget. Here is how the RS3 and TT RS 2.5T intake lineup stacks up:

*AWE publishes +17 whp / +6 lb-ft at the wheels for the Closed system. The Open shares the same filter and inlet tube, so peak gains are comparable, while the Shortie prioritizes airflow and induction sound over a headline dyno number.

Fitment, Install, and What Else You Need

The S-FLO suite is a bolt-on install that most owners complete in under an hour with basic hand tools — no cutting and no tune required, though the intake pairs perfectly with one. Every S-FLO kit ships with a 4.5″-to-3″ coupler to mate to the factory 3″ turbo inlet pipe; if you run a 4″ aftermarket turbo inlet pipe, add the separate AWE 4.5″-to-4″ S-FLO coupler (SKU 7260-11002). Two important notes: 2019-and-newer cars require AWE's billet 6061 DV Adapter Kit to relocate the diverter valve, and because the S-FLO is not CARB-certified it cannot be shipped to California addresses. AWE also backs the intake with its No Check Engine Light Guarantee when installed correctly on an otherwise properly running car. Not sure which configuration or adapters your exact year needs? Our team in Tampa can confirm the right combination for your RS3 or TT RS before you order.