Turbocharger 18559880037/18559880021/18559700021 /07K145701N/07K145701J

B03 Turbocharger (18559880037 / 18559880021 / 18559700021 / 07K145701N / 07K145701J) for Audi RS3, TTRS, RSQ3 with EA855 Engine

The B03 Turbocharger, identified under multiple part numbers such as 18559880037, 18559880021, 18559700021, 07K145701N, and 07K145701J, 

is a high-performance turbocharger designed specifically for the Audi EA855 engine platform. It is commonly used in the Audi RS3, TTRS, and RSQ3 models, 

offering superior power, throttle response, and engine efficiency.

1. Application and Compatibility

This turbocharger is engineered for Audi’s high-output 2.5L TFSI inline-5 engine, known by its engine code EA855. It is featured in the following models:

Audi RS3 (8P, 8V)

Audi TTRS (8J, 8S)

Audi RSQ3 (F3, 8U)

These vehicles are renowned for their performance and sporty character. The B03 turbo ensures the engine delivers strong mid-range torque, rapid spool-up, and consistent boost at higher RPMs.

2. Turbocharger Features

Manufacturer Part Numbers:

18559880037

18559880021

18559700021

07K145701N

07K145701J

Turbocharger Type: Twin-scroll, single turbo

Technology: BorgWarner B03 platform, originally OEM-supplied to Audi

Cooling: Oil and water-cooled

Actuator: Electronic wastegate actuator

Compressor Housing: High-flow aluminum design

Turbine Housing: High-temperature resistant cast steel

The B03 turbo’s twin-scroll turbine housing significantly reduces turbo lag by optimizing exhaust gas pulses from the engine,leading to better efficiency and throttle responsiveness.

3. OEM Quality and Performance

This turbocharger is either OEM-original or meets OE standards through aftermarket production. It provides:

Durability: High-grade materials ensure reliable operation even under extreme temperatures and performance conditions.

Precision Engineering: Every component—from the turbine wheel to the bearings—is designed for high-speed stability and long-term use.

Direct Replacement: Fully compatible with stock hardware and electronics, making installation straightforward for replacement or upgrade purposes.

4. Performance Upgrade Potential

While the B03 is already a powerful stock turbo, it’s also favored by performance tuners and motorsport enthusiasts due to its ability to handle higher boost levels.

With proper tuning and supporting modifications (like upgraded intercoolers, fuel systems, and exhausts), this turbo can comfortably support 400–500+ horsepower, depending on the setup.

5. Market Demand and Export Opportunity

With the popularity of Audi’s RS lineup globally—especially in Europe, North America, and Asia—there is strong aftermarket demand for reliable turbocharger replacements and upgrades. 

Whether you're a wholesaler, performance shop, or international trader, offering the B03 turbo (in both OEM and high-quality aftermarket versions) presents a valuable business opportunity.

6. Packaging and Shipping

Packing: Standard export packing with foam support and protective wrap

Labeling: OEM or neutral packaging available, customizable for bulk orders

Shipping Options: Air freight, sea freight, or express courier available based on customer preference

Warranty: 12-month warranty under normal usage conditions

7. Why Choose This Turbocharger?

Proven Performance: Designed for Audi’s flagship sport models

High Compatibility: Multiple part numbers fit across various EA855 engine models

Excellent Value: OE-level quality at competitive pricing for both retail and bulk orders

Wide Application: Ideal for direct replacement, tuning, or engine rebuilding projects