a3 1.8t quattro dyno results?

[AUDI COUPE 20V]

the ko3s what people call has k04 internalls 8 blade turbine and k03 has 12 blades

[hiltoa]

All the following turbos have the same installation dimensions and thermodynamical performance. The differences are only in the actuator that opens the turbine bypass valve:
K03-011 (5303 988 0011) 150 hp, 65 N actuator
K03-026 180 hp, 85 N actuator
K03-035 180 hp, 85 N actuator
K03-044 150 hp, 65 N actuator
K03-045 156 hp (Ibiza Cupra), 85 N actuator with 2 ports
K03-049 150 hp (Sharan/Alhambra), 65 N actuator
The 180 hp versions have an actuator with a higher opening force due to the higher exhaust gas pressure (which is a consequence of the higher boost pressure). Otherwise the valve would be pushed open by the exhaust gas pressure.

The following turbos are a further development (since 2000) and have an improved and slightly larger compressor while using the same turbine (still with the same installation dimensions):
K03-052 180 hp, 85 N actuator
K03-053 150 hp, 85 N actuator
K03-058 150 hp/180 hp, 85 N actuator

Fantastic post Si
This is why I still lurk on the best Audi forum on the web!

Whether I have a K03 with 85N actuator, or the mythical K03s, I'm still saving for the GTRS Eliminator! Might be able to keep up with (some of) you S2 boys then...

[Audi Parts Guru]

Just for everyones info, the KKK parts catalogue currently lists 10 different K03 compressor wheels and 26 different K04 compressor wheels