I have a chassis dyno in my Conyers shop and it's a great tool for set up, and finding problems. Everything from drive train, to A/F. I really don't care how accurate the power reading is. I use it more as a comparison of where we start, to where we finish. Jetting, nitrous, timing curves, and so on are a snap on the dyno. For sure a good data logger at the track can’t be beat, but at least traction is no issue on the dyno. I can grab the motor under full load and make sure everything holds together, and that the mix isn't going to be destructive. Better sitting still and finding a weak point than at 100 mph.