well 2 weeks ago I dyno'ed my car..
I got 158rwkw. Was quite surpised.
This is stock r33, stock everything. POD and HKS cat back.
On the day stantaic had his auto GTT, that only did 156.0, also a R33 S2 (links's car) did 156.5. Both of them had cat backs and had stock air filter.