Cool idea, but you really are not benefiting any by getting rid of the split. The split is by no means in one bit restrictive. I highly doubt there was any gain from doing this modification over leaving the split there.
2013 Alpine White F10 535i. JB4 S2, Quad Tip Magnaflow Exhaust, H&R Springs
2011 335ix Le Mans Blue w/ M Sport SOLD
2003 Turbo Cobra 765rwhp/650rwtq 9.77@126 pump gas, lifting @ the 1000ft mark