I had installed an s5 turbo in my car before, still had the dreaded creep.

I thought I'd post a pic of how big the passages were ported, there is really room for more yet but it does not creep at ALL at 5psi with a 3" exhaust and TID.

what isn't in the picture is that I also used an angle grinder and cut a LOT out of the back plate on the turbo to allow the flapper door to open further, imo this was very important to aid flow.

probably even makes more power at the same boost level now due to better flow.

 

looks alright yea you could go alot further with porting it look in this link im porting my wastegate right now mine is going to be ported almost as much as this on if i remember i will take a pic and show you mine could you post a pic of your cover plate that you grinded to allow the flapper to open more http://fc3spro.com/TECH/HOWTO/KWG/kwg.html