AET 4094R Hybrid Turbo

My new turbo arrived today, thought I would weigh it compared to the old unit. GT42RS 17kg, the GT4094hybrid 10kg, so thats another 7kg off the weight! I’m now wondering if I can go down to a 3″ or 3.5″ exhaust system to save some more weight. My current 4″ system is very heavy but very quiet at 95db, hmmmm, decisions, decisions.