The Project Pad

I have a k03 from a 2.7t and I was wondering if I can change the housings on it to fit in my A4 1.8t. Basically just swapping the center section and rotating assembly. If I can do this, that would be awesome, my current turbo is making some weird noises.

wheels are likely different size, which means different compressor maps. Why not get a rebuild kit from some place like Gpop if they have one. Or go bigger. If my A4 wasn't an automatic, I'd have a K04 on it.

I've heard that you cannot really rebuild a k03 because the tolerances are so tight. I'd look for a k04!

Yes and no... the main differences between K03 to K03 (and K04 to K04) is the center section. The oil and coolant provisions are often different between models in terms of connection and location. Yes, sometimes there is a turbine and/or compressor wheel difference, but often that can be dealt with by using a different housing that still mates with your downpipe and intake plumbing.

As for K03 tolerances being too tight to rebuild, that's completely false. K03 and K04 turbos all use the same consumable internals, including the shaft. Rebuild kits are readily available from lots of suppliers for <$100.

ur20v wrote:Yes and no... the main differences between K03 to K03 (and K04 to K04) is the center section. The oil and coolant provisions are often different between models in terms of connection and location. Yes, sometimes there is a turbine and/or compressor wheel difference, but often that can be dealt with by using a different housing that still mates with your downpipe and intake plumbing.

As for K03 tolerances being too tight to rebuild, that's completely false. K03 and K04 turbos all use the same consumable internals, including the shaft. Rebuild kits are readily available from lots of suppliers for <$100.

I didn't say nobody sold the parts

This is what I was reading http://www.turborepair.net/rebuilding-k ... hrgers-no/ and, FWIW, I'm not a turbo expert but the logic makes sense to me. Even if you get genuine parts and balance it, you must be nearing the cost of another CHRA or good used K03?

On the other hand, less r less balance required.

why would balancing be required if the compressor wheel goes back on the shaft in the same location? That is how it used to be done, anyway, and how I did a K26 "back in the day"...Not saying to never balance a compressor/turbine assembly.

Balancing is only necessary if you change wheels or do something dumb like drop it on the floor If you do have to have it balanced I know the couple of turbo shops local to me only charge $25-$30. A good quality CHRA starts around $300. To some its worth the extra money to invest in something with a warranty, and others would rather save the $200. I offer my customers new/rebuilt turbos and new/rebuilt CHRAs, but I don't ever offer to rebuild their turbos as my labor rate pushes the cost into CHRA territory. But I do rebuild my own!

Now, is a K03 actually *WORTH* rebuilding? Probably not. Better to find a blown K04 that fits your application and rebuild that instead.

To take advantage of the K04, don't I have to change other stuff too? I was going to do the Unitronic Stage 1+ at Carlisle. Is that ok for a k04? 99 A4 1.8T AEB.

To make full use of the K04, yes, you need to change stuff... injectors (and cups) for one. I'm sure Unitronic has a K04 file. Luckily for longitudinal 1.8t owners (Passats and A4s) you don't have to change all your hardware like the transverse guys do (exhaust manifold, coolant and oil lines, etc.).

And you can use the K04 as a substitute for your K03, if you are happy with K03 performance (when its working right). It just won't be reaching its full potential (and thus extending its lifespan)

So I could do K04 and stage 1+, then if I wanted to upgrade to better software and injectors later, I could do the matching software too is what I'm thinking.