Im planning on getting this turbo for my UrS4 this winter and I wanted to ask you guys a few question. When do you start to make full boost and what A/R is on the hotside? Have you changed to custom software for the turbo,injector setup? VR, Does the car feel faster than your 2001 S4? My plan is to run my current MTM 1+ software, stock injectors for a break in with the GT3071. Do you think I will have any problems until I get the correct software+injectors? My HP goal is to be right around 450-480hp. Im aware of the engine mods required upward 400hp.

The A/R was 0.46 on the hotside.

All my opinions are from Stock Software. That's what I'm running because it's 'relatively safe', while I get the other mods done (brakes, suspension, fueling, S/w)

On stock:
- It makes 0.5 Bar from 3000~
- It really kicks in at 3500, and by 4000 it's full on
- Spools very fast, lag is no worse than K24
- Butt dyno says 260~290hp
- It feels as strong as a Stage 1 B5 S4 (APR but not GIAC/ABT)

I don't know if Stage 1 AAN s/w on Stock injectors is safe with this big turbo. It has big lungs and unlike the K24 it pushes lots of cool air all the way up the RPM scale. I would be worried about getting too lean up top. I'd also be worried about boost spikes which occur when the turbo spools faster than s/w expects, and faster than can be controlled with MAP sensor + N75K.

Running bigger turbos with Stage 1 s/w is common on B5 S4, its called "Stage 3-" :
- Increasing Fuel Pressure 4 -> 5Bar
- Manual Boost Controller to clamp spikes
- Throttle cut disable (MAP sensor clamp)

I do not know if any of this is necessary on the I5, I don't know the range of the stock injectors or the needs of the 3071.

I am going directly to a modified RS2 software & fueling 39lb injectors. It won't be very well tuned, but I have an Innovative A/F LM1/AuxBox, an Apexi EBC, and I'm going to experiment ;-)

Hope that helps

he recently put it on the 200 20v aka EVOKiller! he made 14psi boost at 2700rpm and iirc somewhere around 26psi at 3200rpm. he is extremely happy with this turbo. holds boost hard right up to redline without dropping a single pound of boost. but this is also thanks to his greddy profec-b EBC.