K04 - Should I Rebuild This ?

[Alex_Dubz]

Greetings to all,

Here's the story: I bought two damaged K04-023s for less than 50£, hoping i will end up with a good turbo after a rebuilding process.
I broke the turbos apart and here's what i found:
One of the compressors have been apparently upgraded in the past as it have a bigger wheel with 12 blades that won't fit in the other compressor housing:

Compressor hosings side by side (the left one is stock while the right one is upgraded). Notice that both of them have been "scratched" by the wheel

Back plates also damaged

The upgraded compressor housing is out of discussion as i have no idea what wheel have been fitted in the past and i don't want to risk buying the wrong one. So we're left with the stock one. As the shaft have also been damaged, i was thinking buying a new CHRA and fit the housings. My question is, is this compressor any good to use? My concern is that the gap between the housing and the new wheel will be bigger, due to the housing wear so it won't boost right. Anyone experienced this kind of problem, or knows enough about turbos to put some light here, please do! Closer look on the stock housing:

Should be mentioned that the wear is only on that round surface. On the inlet side where the top of the wheel is, apparently there are only minor scratches.

Any help would be appreciated!

 

[beachbuggy]

Measure the internal diameter of the larger compressor housing and post it up and I'll let you know what it is. I can guess though it'll be 44mm . So it'll be a 2280 ETT compressor wheel.


Are the turbine wheels the same on the turbos?

 

[Alex_Dubz]

To be clear, both compressor were identical in the past as they have the same part number stamped and both turbos were K04-023. One of them have been machined to accept the bigger wheel.
Now, i measured the internal diameter of the inlets and you were right, the upgraded one is 44.1mm while the stock is 42.4mm.
Did some measures on the wheels also if it helps. The bigger wheel is 27.7mm total height with 56.1mm total diameter (on its base) while the stock is 25.7mm total height and 56.2mm diameter. Other measures are useless as the blades are damaged. Shaft and everything else is the same.
Pics with the upgraded compressor housing:

Tried to google for more info and i found this link: K04/16 Upgrade Umbau-Satz Audi tt 8N Turbo : Biete Audi
so could be a K04/K16 hybrid i guess, or K04-0240, whatever that means that i found on a forum in a strange language but i got the picture:

 

[beachbuggy]

What you have is a stage 1 or possibly 2 turbo . If the turbine is the same then I did a similar unit for badger5 at the end of last year. Its a pretty basic upgrade to a stock k04. That compressor is only really any good when hooked up with the rs6 turbine. Its not a k16 version.

 

[Alex_Dubz]

So what should i do? I was considering more to rebuild the stock one as i said, cause i can just buy a new CHRA for 180 pounds, but i don't know if that stock compressor housing is any good due to the wear of it.
With the upgraded one, i can still buy a new CHRA and switch the compressor wheel with the upgraded one that i need. To me, fitting a slightly bigger compressor wheel to the same turbine actually sounds good, as in theory i'm increasing the amount of air while keeping the spooling at the same level. Or am i wrong?

 

[Alex_Dubz]

If this chart is correct, i would say i have the 2277 wheel, right?

 

[Prawn]

They both look pretty ****ed to me! As do the housings!

 

[Alex_Dubz]

It was the housings that i was interested for, of course the wheels are useless. Just wanted to know witch one should i buy. Anyway, i quess i'll go for plan B. Cheers!

 

[s33nyboy12]

It was the housings that i was interested for, of course the wheels are useless. Just wanted to know witch one should i buy. Anyway, i quess i'll go for plan B. Cheers!

. Lol!

 

[Prawn]

That's amazing!!!!

 

[superkarl]

Its the inducer measurment you need, the top diameter, thats what seperates and defines the wheels. With the inducer size you could find out what wheel, and dan would most certainly tell you which one it is from that.

 

[Alex_Dubz]

My opinion is that the wheel was a 43mm inducer due to the 44mm internal diameter of the housing inlet. But i will let go the idea of rebuilding it, cause I'm not sure if that compressor housing is any good, probably not, so i won't take the risk. I guess i'll go for a TD04L turbo as it's just sooo much easier to work with than the KKKs. The compressor wheel is almost identical to the K04 being 41/56 (k04 - 42/56) but with a smaller turbine so it spools quicker. Think that would be the best for my ~250hp target. Also you can find any part for it if you ever need something.