I was looking at my s5 t2 lim, and was thinking about improvements. I was looking at the 2 center ports and noticed that for the center mounting hole, there is some of the casting that would be nice if it was smoothed out, but also was scared that if it was ported too much, you could make a hole where the center bolt was. Anyone port theirs?

 

I ported my S5 LIM including the area of the center bolt boss you are talking about.

I didn't get a hole there, but I was fairly conservative- just smoothing/flattening the intrusion into the runner.

I never put it on a flow bench to see if I got balanced flow, but I did have dual EGTs and under boost front/rear EGTS were right on.