I have had all my tuning work done at AMD and have been very happy with the results. From standard to stage 1 and stage 1 to stage 2 have been massive improvements in the way the car drives. Each time on the RR it shown a healthy power increase and the last time it showed 272bhp. However with the same mods etc I went to JKM's RR in October and made only 255bhp
. I am not worried by this variation as the car feels great and has improved each time it has been to AMD.
As long as you feel the improvement in the car the RR figure is not that important as long as it has improved on the same RR that you used previously. I really don't understand why readings vary so much from one RR to another.