I use a chassis dyno a LOT. Did an EFI conversion on a TS car earlier in the year. The quickest pass it had ever made with carbs and two nitrous kits was a 4.16 in good air..........I did all the EFI tuning on the chassis dyno, including lighting both stages of nitrous. He put it in the trailer, headed to Dallas for PDRA season opener, with NO track time. First pass, right off the trailer with the chassis dyno tune, was a 4.17 @ 171. Has since been a 4.10 on two kits in really good air

I also tune Chad's car on the chassis dyno. It has 4 kits, but have only sprayed the two small ones on the dyno. It makes over 1400 to the tire on the first two