2010 GTI Turbo

[REXman]

Borg Warner makes the turbos for us and also for KKK, Kühnle, Kopp & Kausch, which can be found in heaps of other cars so there's no realy one company that makes the 'k03' sized turbo.

Differences between k03 and k04 are minimal... if you were thinking of upgrading to a k04

edit: forgot to mention, k03 left. k04 right

Housing looks slightly larger on the K04.. but obviously its the internals that make it. Look at the propeller difference.. the K03 has smaller, more tightly parted fins.. The K04 has them wide apart.. not sure if the actual propeller is only more aggressive with a larger housing..or if the diameter is bigger as well.. either way really your gonna get more power with the one on the right

I know out of the T25 and T28 which one i'd rather driving me.. this looks like a similar case.

[Corey_R]

I saw on APRs website for the turbo upgrade for the MkVI GTI that the upgraded turbo has a removed turbo noise reducer... Does this mean have a turbo noise reducer on our stock engines???

Well, your stock engine doesn't have a K04, so the comparison pictures on their website are not against the turbo in your car. They're comparing to the turbo in the Golf R/Audi S3/MKV GTI Pirelli etc.
Whether that feature is also on the K03's used in the GTI's is not known to me.

[AdamD]

Housing looks slightly larger on the K04.. but obviously its the internals that make it. Look at the propeller difference.. the K03 has smaller, more tightly parted fins.. The K04 has them wide apart.. not sure if the actual propeller is only more aggressive with a larger housing..or if the diameter is bigger as well.. either way really your gonna get more power with the one on the right

I've read that the housings themselves are identical between the K03 and K04. But the internals themselves are quite different, as you say, hence all that extra power from the K04.

According to that link I posted previously, the maximum flow rate is 0.17kg/s for the K03 and 0.21 for the K04. I'm sure there's a lot more to it than flow rate alone, but that's almost another 25% right there.

[gecko2k]

As far as I know, the K03 is from Borg Warner. (Perhaps BW bought out KKK's turbo designs when Siemens bought KKK?)

Afai KKK was bought years ago by Borg Warner. Must be roughly about 10 years ago, I just remember that because my school bus would pass a KKK factory every morning on the way to school and from one to the other week it was called 'Borg Warner'...

[TeamCrash]

Bigger fins in the k04, which as said then means a bigger housing. performance is up. I was reading somewhere the figures but remember I will try and dig it all out