Borgwarner Audi 1.8L Factory Upgrade K04-01 Turbo (5304.950.0001) (199 – AET Turbos
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Borgwarner Audi 1.8L Factory Upgrade K04-01 Turbo (5304.950.0001) (1996-2001)

Borgwarner Manufactured

  • £660.00
  • Save £90.00

Please ensure this is the correct turbo for your vehicle, if you are unsure in any way please call our support team on 01924 894171.

Product Description

Part Number


Upgrade from 53039880052/53039880053/53039880058


Vehicle Manufacturer Audi
Model Audi A3, A4 Upgraded, TT (1996-2001)



 Comp Wheel O.D (mm) Comp Wheel Inducer (mm) Turbine Wheel O.D (mm) Turbine Wheel Exducer (mm)
50.04 37.6 46 42



This is a genuine new factory upgrade turbo by Borgwarner utilising features from the Airwerks performance range, built specifically for Audi 1.8 litre engines. This upgrade option can enhance performance up to 15% max power output (dependent on engine condition and other performance factors)

Please check additional Information tab above to ensure you have the correct turbo to fit your vehicle, if you have any questions please do not hesitate to contact us, our email address is or you can call us on 01924 894171 Monday to Friday 08:30 to 5pm


All our turbo units except competition units carry a 24-month warranty, or 24,000 miles for petrol, 50,000 miles diesel whichever comes first, this is from the date of invoice, provided that they are fitted in accordance with the manufacturers fitting guidelines and are not fitted to a worn/faulty/contaminated engine. AET Turbos recommend fitting a new oil feed pipe and the use of high quality synthetic/semi-synthetic oil, which should be changed according to manufacturer’s recommendations or every 6,000 miles if no guidance is available. Please see our terms and conditions for further information.

We send fitting instructions with every turbo dispatch.

Minimum-Flow Point Set Correctly Every Time.

All AET Variable Geometry (sometimes called VNT or Variable Vain) Turbo are flow tested to ensure the critical minimum-flow stop is at the correct setting before your turbo leaves our workshop. This will ensure your turbocharger will give your vehicle optimum performance and В fuel efficiency from the moment it is fitted.

The Highest Standard in Turbo Quality

Quality has been at the forefront of every decision we have ever made, a fact that was recognised in 1990 when we became the first British turbo re manufacturing company to be awarded the ISO 9001 accreditation. Today, it still remains the case, and that is why we carry out work for the majority of the OE manufacturers. We were responsible for the design of many of their quality system processes. From the design of our rigorous testing processes, to the choice of our brand partners, we are committed to delivering the very highest standard of quality of turbos, spares and advice to our customers.

Your ISO Guarantee.

ISO 9001 is an international Standard that acts as your guarantee that you will receive the same level of quality assurance and service from AET as you would do if you were dealing directly with the manufacturer.

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