We just finished tuning an M5 E34 with 3,6liter motor, CP pistons, Pauter rods etc. Turbo is Holset HX50 with 17 cm2 turbine. Made 622rwhp @ just 0.95 bar boost and full boost is already available @ 3300 rpm.
Today was a One Mile Challenge event (standing mile), result was 303 km/h. Next step is to up the boost to 1.4-1.5 bars and traget is at least 900 hp.
This is just for reference, turbo cost €200 from the local truck scrapyard but to be fair, the truck had low mileage before it crashed lol
