I just changed the solenoids. Turbos spool faster and hold boost better. They still rattle though.
SOLD --'07 E90 335i, PTF COBB E50, HFS4, ER CP, ETS 7", AA DP, Vishnu Exhaust, DCI, ACT, Nitto Nt555
SOLD '10 E92 335i M, 6MT COBB v3, ER IC, ER CP, VRSF DP, Fuel-it st2, Mfactory LSD