The early 1.8T engines, and many subsequent engines have used similar turbos but I was wondering what are the differences between the K03 K03s and K04 turbo units.
Are they interchangable and what power figures are they good for?
KO3 turbo has 12 blades, and with the right supporting mods can release power around 200bhp, the
K03s has 8 blades, although lower than the KO3 the K03s will support around 220 to 250bhp.
K04 can flow to provide around 250-300bhp
The K04 is a larger turbo unit and came in 3 versions!
K04-020 no temp gauge aperture in the housing
K04-022 no temp gauge aperture in the housing
K04-023 with the temperature gauge aperture
When remapped you should see an easy 250bhp on the stock 1.8T and with other mods the K04 can flow to provide around 300bhp.
All you need to know about these turbos from the VAG group, including power limits, swaps and differences between them and best upgrades for your project car.