Sounds like I probably won't have a problem with warranty so I might just get the Hi Flow Cat/downpipe.
After checking with Revo, the 15% increase in power with stage 2 is 15% of the increase (55bhp), not 15% of the total (255bhp) as I said earlier. So I guess with a filter, Milltek and stage 2 you would be looking at around 270bhp
RedRobin, I'm also thinking of the Neuspeed turbo discharge adapter/pipe. What difference did you find with this fitted, did you feel any increase in power?
TT, as you know all

do you know the reason why their is a small restrictive chamber placed on the discharge side of the turbo and not a straight flow path like the Neuspeed or Oettinger adapter?