i don't know much about the m50 or m52 motors but i know the m30 is better than the m20 for turbos because the block is much stronger.
Current:2013 Candy White VW Golf TDI
Sold:2004 Silver Gray M3
Mods: Dice Unit, EAS Angel Eyes, Painted Reflectors, CSL Diffuser, Smoked Corners, PSS10s, 15mm Front and 10mm Rear Spacers.
Gone:1990 Brilliantrot 325is
Mods: Alpine speakers and HU, Euro Projectors, Magnaflow Muffler, Euro Smoked Tails and GC Coilovers.