Good evening.
I have a s200sxe s257 supercore and I was thinking about getting a turbine housing for it.

What is the best option for me to get on a 2.1 liter to give me full boost around 4500 while not choking the car at top end
T3 twin scroll 1.0 A\R
T3 twin scroll .83 A\R
​​​T3 single scroll. . 82 A\R

Power goals : 500 wheel horsepower on e60 or e70
The engine is built 2.1 liter, fitment for the turbine housing is not an issue, I can order custom made headers, uppipe and everything I need.

Other question I have on mind just out of curiosity, let's say XX turbo was installed on a wrx and on an Evo 8 for example with the same turbine housing for both cars which​​​​​ car will spool the turbo first and which car will make more power
* both cars are 2.0 liters

 

Not a horrible turbo to run on a 2.1L and I would go with the 1.0a/r T4 TS on a small runner manifold. The compressor flows 65lbs/min on the S257 SX-E so it will very easily will support 500hp@wheels on E60.