I was thinking about this for a while. I was wondering if it were possible to use the ko4 housing so it would bolt right up to the 2.7, use the 997 comp, and use the rs6 hotside since it is bigger than a ko4 hotside. Would this be possible? Or even worth while? Ik they sell rs6 kits but I already have ko4's and the rs6 needs to be modded to bolt to the 2.7 motor.

 

Hi XxRomeSDSxX,

In picking the right compressor/turbine combo, bigger is not always better. Where are you heading with this?
• Just more boost for the stock engine?
• Different ECU?
• Exhaust system?
• Rebuild engine?
• “Ultimate Power”?

Over-sizing a turbine or compressor can force either, or both, to operate at low efficiency.

vonk

 

I want the most power squeezed out of the stock internals until I do build the bottom end. right now I have a ecu flash, which I will have to get a stage3 flash and a 3in exhaust from the turbos back, also not installed are rs4 injectors.

 

Sounds like fun:

I believe that should give you more than RS4 equivalent performance, your 3” exhaust compensating for the lack of RS4 cams. You’ll be in the K04 turbo operating range, with the turbine benefitting from the freer exhaust. With a Stage3 ECU, the compressor may lose a little efficiency at higher than RS4 boost (17.4 PSI), but you’ll trade off a minimal amount of top HP for a fatter torque curve below that.

I went the same route with some added intake mods (see my garage) and got around 430 HP out of it at 27 PSI boost. I really liked the K04s for their quick response and smooth power delivery. Of course I was lucky with the Stage 3 ECU from APR.

Knowing how critical it is to match the compressor and turbine performance maps to a given engine, I have always been skeptical of hybrid turbos based on the bigger is better philosophy alone.