the best guy to flash a ecu while dynoing it is chris at cjsracing in bristol he had mine on a dyno for 4 hours plus the guy is superb,
there are 1 or 2 others that alot use to flash ecu but they don,t dyno chris is superb at it.
CJS Racing is a specialist engine workshop focusing on ECU reprogramming and Dyno tuning for Superbikes, Jetskis and Outboard engines. Located in Bristol UK
+1 for Chris at CJS. He flashed both my Zx14r and my S10 and in both cases it improved them amazingly. He got 214bhp from my Zx14r and 103bhp from my s10. The the BHP figure is only half the story. When properly mapped on the Dyno both bikes are much easier and smoother to ride at normal speeds. Throttle response is smoother and there is far more low down grunt to pull you out of corners.
CJS is in the south of England near Bristol.
My other go to ecu / Dyno tuner is John Warrington at Malton in North Yorkshire. John is a true gentleman and a magician on the Dyno.