Cold Air Intake for Audi TT & Volkswagen Golf GTI Jetta Jetta GLI (1999-2006) MK4 1.8T

High-Flow Cold Air Intake for 1999-2006 Volkswagen, Audi TT, Golf GTI, Jetta, Jetta GLI (1.8T MK4/MK1)

What it Does: Replaces the restrictive factory air box with a mandrel-bent induction system to lower intake temperatures and maximize oxygen density for the 1.8T turbocharged engine.

The Stock TT, Golf GTI, Jetta, Jetta GLI Airflow Restriction

The factory intake system on the 1.8T EA113 engine utilizes a series of restrictive baffles and a sealed plastic air box designed primarily for NVH (Noise, Vibration, and Harshness) reduction rather than peak volumetric efficiency. This design forces the turbocharger to work harder to pull air through a dense, pleated paper filter, creating significant pressure drops within the intake tract. Furthermore, the proximity of the stock housing to the cylinder head results in severe heat soak. During extended operation, intake air temperatures (IATs) climb rapidly, leading the ECU to pull ignition timing and reduce boost pressure to prevent detonation, which significantly hampers performance.

The Engineering Solution

This cold air intake system engineered for the MK4 and MK1 platforms utilizes high-diameter, mandrel-bent aluminum piping to provide a smooth, laminar flow path directly to the turbo inlet. By relocating the air pickup point and utilizing an open-element high-flow filter, the system draws in cooler, denser air from outside the high-temperature engine bay. The increased surface area of the filter media reduces vacuum resistance, allowing for faster spool-up and improved throttle response. Constructed with durability in mind, the kit includes heavy-duty couplers and clamps to ensure a leak-free seal under vacuum. This mechanical upgrade is essential for maintaining consistent power delivery and avoiding the thermal bottlenecks common in the 1.8T's stock configuration.

Technical Specifications

Compatibility

• 2000 - 2006 Audi TT MK1 1.8T
• 1999 - 2006 VW Golf GTI MK4 1.8T
• 1999 - 2005 VW Jetta MK4 1.8T
• 1999 - 2005 VW Jetta GLI MK4 1.8T

The Volkswagen & Audi Precision Standard

Engineered to meet the tight tolerances of European powerplants, this intake system provides a direct bolt-on fit without the need for permanent modifications. Designed for the 1.8T enthusiast, it delivers a more aggressive induction note and improved turbo bypass valve sound without triggering Check Engine Lights (CEL), ensuring your MK4 or MK1 maintains its precision-engineered drivability while benefiting from increased airflow capacity.