CTS Turbo High-Flow Intake w/ 6" Velocity Stack – Audi B9 A4 / Allroad / A5 / S4 / S5 / RS4 / RS5

Feed your B9 Audi’s turbocharger with the unrestricted airflow it deserves — the CTS Turbo High-Flow Intake with 6" Velocity Stack is one of the most effective bolt-on intake upgrades available for the B9 platform. Engineered for the Audi B9 A4, Allroad, A5, S4, S5, RS4, and RS5, this intake replaces the restrictive factory airbox with a high-flow design featuring a 6-inch velocity stack that maximizes airflow volume and velocity into the turbocharger inlet. The result is improved turbo response, increased power output, and a more engaging induction sound — all from a direct bolt-on installation.

Key Features:

• 6" velocity stack — large-diameter velocity stack maximizes airflow volume and velocity into the turbocharger inlet for improved turbo response and power
• High-flow design — significantly less restrictive than the factory airbox, reducing intake restriction and improving turbocharger efficiency
• B9 platform specific — engineered for the Audi B9 A4, Allroad, A5, S4, S5, RS4, and RS5
• Direct bolt-on installation — uses factory mounting points for a clean, no-fabrication installation
• CTS Turbo engineering — designed by one of the most respected names in VAG performance parts
• Pairs with CTS intercooler and tune — designed to work seamlessly with CTS Turbo’s full B9 performance lineup

Performance Benefits:

• Increased Airflow: The 6" velocity stack and high-flow intake design deliver significantly more airflow volume to the turbocharger than the factory airbox — reducing intake restriction and improving turbocharger efficiency across the RPM range
• Improved Turbo Response: Less intake restriction allows the turbocharger to spool faster and more efficiently, improving throttle response and mid-range power delivery
• Power Gains: Increased airflow volume and reduced restriction translate directly into measurable power gains — particularly when combined with a tune that optimizes for the improved intake flow
• Velocity Stack Advantage: The 6" velocity stack’s bell-mouth entry profile smooths airflow into the intake, reducing turbulence and improving the efficiency of air entering the turbocharger inlet
• Induction Sound: High-flow intake design produces a more engaging turbo induction sound under acceleration — a more visceral, connected driving experience compared to the muffled factory airbox
• Tuning Headroom: Reduced intake restriction gives your tuner more room to optimize boost, timing, and fuelling for additional power gains

Specifications:

• Brand: CTS Turbo
• Part Number: CTS-IT-290R
• Type: High-Flow Intake
• Velocity Stack Diameter: 6 inches
• Fitment Style: Direct bolt-on
• Compatible Platforms: Audi B9 A4, Allroad, A5, S4, S5, RS4, RS5

Fitment Information:

• Audi A4 B9 — 2.0T TFSI (EA888)
• Audi Allroad B9 — 2.0T TFSI (EA888)
• Audi A5 B9 — 2.0T TFSI (EA888)
• Audi S4 B9 — 3.0T TFSI (EA839)
• Audi S5 B9 — 3.0T TFSI (EA839)
• Audi RS4 B9 — 2.9TT TFSI (EA839)
• Audi RS5 B9 — 2.9TT TFSI (EA839)
• Note: Verify your specific year and engine variant before ordering. Some model years may have different intake configurations — confirm fitment with CTS Turbo’s fitment guide before purchasing.
• Tune: ECU tune strongly recommended after installation to take full advantage of increased airflow

What’s Included:

• CTS Turbo high-flow intake with 6" velocity stack
• All mounting hardware and couplers
• Installation instructions

Installation Notes:

• Direct bolt-on installation using factory mounting points — no fabrication required
• An ECU tune is strongly recommended after installation to optimize for the increased airflow
• Inspect all couplers and clamps after installation to ensure airtight connections — boost leaks will negatively affect performance
• Professional installation recommended if unfamiliar with intake system components

Velocity Stack Design:

A velocity stack (also called a ram stack or trumpet) is a bell-mouth shaped intake entry that smooths the transition of air from the atmosphere into the intake tract. The curved entry profile reduces turbulence at the intake inlet, allowing air to enter more efficiently and with less energy loss than a flat or sharp-edged entry. At 6 inches in diameter, the CTS Turbo velocity stack provides a large, smooth entry point that maximizes the volume of air available to the turbocharger — particularly beneficial at high RPM and boost levels where intake restriction becomes a significant limiting factor.

The B9 Audi Platform:

The Audi B9 platform — spanning the A4, Allroad, A5, S4, S5, RS4, and RS5 — represents one of the most capable and tuning-friendly VAG platforms available. The EA888 2.0T in the A4/A5/Allroad and the EA839 3.0T supercharged/turbocharged V6 in the S4/S5/RS4/RS5 both respond exceptionally well to intake, intercooler, and tune upgrades. The factory intake systems on these platforms are designed for noise suppression and emissions compliance — not maximum airflow. A CTS Turbo high-flow intake is one of the first and most impactful bolt-on modifications available for any B9 build.

Why CTS Turbo?

CTS Turbo is one of the most respected names in VAG (Volkswagen Audi Group) performance parts, with a comprehensive lineup of intake, intercooler, turbo, and exhaust components for Audi, Volkswagen, and SEAT platforms. Their B9 intake components are engineered specifically for the platform — not adapted universal parts — ensuring proper fitment, correct coupler dimensions, and compatibility with the rest of the CTS performance lineup.

Perfect For:

• Audi B9 A4, Allroad, A5, S4, S5, RS4, and RS5 owners seeking a high-flow intake upgrade
• Stage 1 and Stage 2 B9 builds pairing with a tune for maximum power gains
• Builds seeking improved turbo response and a more engaging induction sound
• Anyone replacing the factory airbox with a performance intake as the first step in a B9 power build
• CTS Turbo ecosystem builds pairing with CTS intercooler, downpipe, and tune for a complete performance package

Pro Tip: Pair with a CTS Turbo intercooler and a quality ECU tune for the most significant power gains from the B9 platform. Intake alone delivers measurable improvement, but the combination of intake + intercooler + tune unlocks the full potential of the EA888 and EA839 engines.

Note: An ECU tune is strongly recommended after installation. Running factory maps with a high-flow intake leaves power on the table and may trigger MAF-related fault codes depending on your specific configuration.