Upgrade your Volkswagen or Audi 1.8T with the XS-POWER K04-001XLB billet turbocharger, a high-performance replacement designed for enthusiasts who want substantially more airflow and power potential than a standard K03-style replacement turbo.

This upgraded K04-001 platform features a large EO5-style billet compressor wheel measuring 46.5mm inducer and 56mm exducer, paired with a 44mm / 50mm turbine wheel. The combination is engineered to provide strong airflow, responsive spool characteristics and improved top-end performance while retaining a compact turbocharger configuration for transverse Volkswagen and Audi 1.8T applications.

Unlike basic replacement units that simply restore factory performance, the K04-001XLB is built for modified vehicles using upgraded fueling, intercooling, exhaust and ECU calibration. Its enlarged billet compressor provides significantly more airflow capability than a conventional K03, making it an excellent option for street performance, autocross, roll racing and responsive daily-driven builds.

This listing includes the turbocharger and gasket kit only. The turbo inlet pipe, software, injectors, fuel pump, manifold, intercooler, downpipe and other supporting components are not included.

Many replacement turbos advertised for the MK4 Volkswagen 1.8T are little more than stock-size K03 units. Those turbos may restore factory operation, but they do not deliver the airflow required for a serious performance build.

The XS-POWER K04-001XLB uses a much larger billet compressor package and upgraded turbine dimensions to increase flow capacity while maintaining the quick response that makes the 1.8T platform so enjoyable on the street.

• More airflow than a standard K03 replacement
• Larger EO5-style billet compressor wheel
• Improved high-RPM breathing
• Responsive boost characteristics
• Compact K04-001-style configuration
• Excellent foundation for a tuned 1.8T street build
• Designed for enthusiasts seeking strong power without moving immediately to a full-frame turbo conversion

• Substantially greater compressor airflow than a stock-size K03 turbocharger
• Stronger mid-range and top-end performance when properly tuned
• Responsive boost characteristics for street-driven applications
• Supports upgraded intercooler, exhaust and fueling systems
• Improved power potential without moving to a large external-wastegate turbo system
• Excellent for quick-spooling 1.8T builds
• Suitable for daily driving, autocross, road course, drag and roll-racing applications

Final power output depends on boost pressure, engine condition, ECU calibration, fuel quality, intercooler efficiency, exhaust flow, fueling capacity and supporting modifications. No fixed horsepower figure is guaranteed.

Designed for compatible transverse Volkswagen and Audi 1.8T applications using the K04-001-style turbocharger layout.

• Volkswagen Golf MK4 1.8T
• Volkswagen GTI MK4 1.8T
• Volkswagen Jetta MK4 1.8T
• Volkswagen New Beetle 1.8T
• Audi TT 1.8T transverse-engine applications
• Selected 2000-2006 Volkswagen and Audi 1.8T applications
• Selected APH-powered Volkswagen New Beetle 1.8T applications

Common enthusiast search applications include:

MK4 GTI turbo upgrade, MK4 Jetta 1.8T turbo, Volkswagen Golf K04 upgrade, New Beetle 1.8T billet turbo, Audi TT K04-001 turbo and transverse 1.8T EO5 turbo conversion.

This is a performance turbocharger and should be installed as part of a properly planned system. Depending on the desired boost and power level, supporting upgrades may include:

• Custom ECU software calibrated for the turbo and fuel system
• Upgraded fuel injectors
• Higher-capacity fuel pump when required
• High-flow turbo inlet pipe
• Upgraded intercooler
• High-flow downpipe and exhaust system
• Proper diverter valve or blow-off valve configuration
• Fresh oil supply and return lines
• Correct coolant-line routing
• Wideband oxygen sensor and boost monitoring
• Upgraded clutch or transmission components when necessary

• One XS-POWER K04-001XLB billet turbocharger
• Turbocharger gasket kit

Not included: turbo inlet pipe, intake hose, software, injectors, manifold, downpipe, intercooler, oil lines, coolant lines or other supporting components unless specifically shown in the product photographs.

Professional turbocharger installation and custom ECU calibration are strongly recommended.

Before startup, confirm that all oil and coolant passages are clean and unrestricted. Prime the turbocharger with clean engine oil, crank the engine without ignition or fuel until oil pressure is established and verify that there are no leaks.

Never reuse contaminated oil lines from a failed turbocharger. Foreign material, restricted oil supply, excessive sealant, improper drain routing, incorrect boost control or inadequate tuning can quickly damage a new turbocharger.

Allow the engine to idle after initial startup and inspect all oil, coolant, intake and exhaust connections before driving under boost.