The next substantial jump in power output for our 135i, will come as a result of the Garrett GT2860R-5 conversion.
There is still some power left on the table with the RB turbos, but I suspect it will be no more than 10 rwkW, perhaps 15 at the very most.
our last tuning session saw our little 1'er dyno up at exactly 349.9 rwkW, I kid you not, what a f'n tease.
I will have to post up the dyno graph when I get a chance.
we could no doubt crack the 350 mark with another 1-2 psi of boost, but our testing thus far suggests as nice of an upgrade as the RB turbos are, they are out of their efficiency range at 20 psi above 5,500 rpm.
I would rather look after the RB's and not push them too hard, so I can sell them in the future, to help fund our Garrett twin -5 conversion.