slappy_dunbar

For months now I've been following various S4 drivers who are or have considered the RS4 turbo upgrade. Obviously, the -025/-026 are in a different class from the K03s stock on the S4. But they're kind of an old design. And they're a long way from the Garrett-based kits. Is there any room for something in the middle, somewhere shy of full-on Eliminators, which would fit like K04's?

Indyxtype

RS6 turbos or a hybrid turbo

donromani

skip the hybrids IMO and go for the RS6 or Tial kit. Garrets require lots of work and a huge amount of money - the RS6 needs a bit of extra work too (new flanges welded to the DPs) not sure about the tials.

slappy_dunbar

What hybrids?

donromani

Well certainly skip the KO4/K03. The other hybrids I know of are RS6/RS4 hybrids, which is probably what indx was talking about. The K04/K03 hybrids are not as good as pure K04s (by definition)

slappy_dunbar

I agree that the designs that retain anything of the OEM S4 configuration are just a disappointment. In the context of pulling the engine to install the turbos, it seems a bit foolish to prioritize retaining the car's original intake pipes over all else.

The RS6 hybrids I've seen are really just 025/026 turbos with the RS6 compressor wheel. That's good for 1.5lbs more per side. Not amazing, but it's a step up for sure. What would you say the downside is from standard K04s?

complacentsee

The hybrids are statisically not as reliable. And the K04s require new intake piping. RS4 intake piping... So I don't know what you mean by that.


Usually the limiting factor IMO is the exhaust manifold flang, or stock internals.

donromani

Only downside to the RS6 hybrids vs. the K04's is that they are more expensive and as comp said less reliable. This is why I would avoid hybrids and just choose a "pure" set-up, either RS4 or if bigger is needed RS6, Tial or some of the smaller garrets although there are no good kits for the smaller garrets so it's probably not even worth considering.

slappy_dunbar

I was referring to the K03 hybrids "advantage" of not requiring new (RS4) intake piping.

Limiting the question to RS6/RS4 hybrids, how certain are you of reliability problems? The products I've seen (VAST/JHM) incorporate OEM 3K Warner parts, so build quality is comparable, It follows, then, that the failure rates would be in line with OEM. Strictly speaking, though, these units aren't really hybrids, they're RS6 turbos with re-shaped charged-air outlets. Perhaps this is a bad example.

Do you mind telling me more about the unreliable units you are familiar with?

complacentsee

Buhen Time Bombs, specifically.

My bad on the k03/k04 hybrids, I think most people went with them since you could get them for about the same price as K03s and people thought, "well they are part k04 they must be better" There are also some hybrids with porsche turbines.