jeff28

Is the only difference between K03 and K04 the turbine wheel? If no then what are the others?

CMH

I am pretty sure the housing is a little bigger on the inside.

Juan M.

the cast housing is diffrent from K03 and K04. K04 is thicker compressor wheel is about 1.5mm bigger but what counts is the pitch of the blades. the pitch which is the A/R is more agressive than the K03.

the exhaust side on the 04 is bigger but not by much... i have not gotten the exact measurements on these.

i am trying to get the stats on the VTN series of the K04 and K03. the new 00-02 cars have the vtn K03 which has been badged as regualr K03's since the old ones are long gone due to update. the K04's are next and i am not sure when this will hit the market. but there is not much improvmen on the K04 just bearing assembly. the wheels stay the same unlike the K03's which got bigger.

i will find out when 3K sends me some info....

Juan M.

xr4tic

so you're saying the "new" K03s are bigger than the "old" K03s? Can you tell them apart at all?

Mike O.

K03 and K04 use the exact same turbine housing. The wheel on the K04 is slightly bigger (~1.5mm).

The compressor housings are different.

The A/R ratio is actually the Area/Radius ratio and has nothing to do with wheels. The A/R ratio refers to the ratio of outlet Area to the scroll Radius. The bigger the A/R, the bigger the scroll for a given outlet area. A bigger A/R for identical outlet areas will spool more slowly but flow more efficiently at high CFMs.

There are pitch designations for all wheels but let's not get everyone too confused.

Trim levels refer to the degree to which that wheel has been modified to change it's efficiency. Sometimes, a turbo shop will cut the blades to reduce the surface area of each blade, thus reducing its efficiency and the rpms a given energy level will produce. Other times, the actual pitch of the blades will be modified to increase the efficiecy for fast spool up. There are reasons to do one over the other that have to do with matching turbines and compressors.

Regarding VNTs: I did not know that the VNTs were being used in gasoline engines yet. VNTs are being used in Europe on diesel VW/Audis. The trouble with VNT turbos is that they have a hard time dealing with the higher EGTs that gas engines produce (because of the number of moving components inside the scroll). Please let me know if VAG has indeed started to use VNT technology in gas engines.

Thanks,
Mike O.

Audiboy

Hey Juan, do you know where I can find an Aerodyne for cheap $$$ TIA

dingster

I think he said VTN, maybe it's just a designation of the newer turbos?