Say what.. 421HP with a 2871R ? Thats alot m8.. What other mods have you done internal ? What about NM ? Currently im running 35xHP and 47xnm with the stock K04 turbo and it's blowing all it can without a doubt.
The reason for the bigger 3071turbo is that it's capable of alot more than the 2871R. My goal is to first get approx 400 and then later on upgrade all the internals and then crank it up to 500+
Fuelpump just got here, quaife diff has been her some time, just need to mount it - and im ordering a custom intercooler when the fuelpump is on

About software im kinda diffent to everybody else.. We do the tuning ourself on the road.. That way we can push everything max. I haven't yet seen a Cupra faster than mine
Im thinking :
APR Fuelpump --> Clutch / Diff --> Intercooler --> RS4 injectors --> 3071turbokit.
We already have a full ATP 3071 turbokit for a friends cupra with every part to make 500+. just need the time to make it. Including every internal part, so it wont blow up

Big
problem is as far as i can see, the fuelpump. Everything else is just plug'n'play, or am i wrong ?