I'm under the impression that there is a friction table on the DTS and the Studka dynos that can be adjusted for the flywheel wieght, IE aluminum 17 lb wheel or a 40 lb steel wheel The DTS uses a large diameter steel plate bolted to your flywheel, the Studka driveshaft bolts directly to the crankshaft usually with no flywheel or flexplate I had one customer who I had built a 484 C.I. RB pump gas street motor that he had supplied a really bad set of Mopar Stage IV heads that had the seats sunk really bad, it made 496 HP on the best pull with changing a bunch of parts. He made a comment to the dyno operator that he was really hoping to make 500 HP with that motor, the dyno operator shut the motor down and went into one of the tables in the software and made some changes to them, the next pull made 504 HP I ask the dyno operator several months later what he did to do that, he siad he change the friction table, IE flywheel weight I told him to never do that on any of my motors agian Even if I begged him to, he said okay On the local Studka dyno the current operator had been running it without calibrating it, once he did the calibrattion,maybe 20 minutes max to do it, with his shops race motor on it the dyno showed a hundred HP and comparable torque loss on that motor I had dyno tested one of my motors on it and then took the same motor with no changes to a DTS dyno in Klamath, OR which is at 4300 Ft above sea level versus 2500 Ft above at the Studka dyno, my motor showed 100 HP less on the DTS dyno After bringing back to the Studka dyno with the 17 lb flywheel still on the Studka operator wanted to use my flywheel, 8 bolt Hemi pattern, on his motor to see how much differences the flywheel would make on there motor. The Studka does have, I think, a friction table, it may be label some other name that escapes me right now Using the flywheel makes a lot of difference on the throttle response on the Studka dyno, both the DTS and the Studka have electric operated throttles, the DTS does a btter job of not letting the motor rev sky high when you go to WOT to begin a pull, the Studka lets it go way above the preset RPM you set to start the pulls at before it slows it down so you can start the pull at or below that preset RPM Have fun and keep in mind that all dyno are a measuring tool to use the measure changes that you make on the motor that day You should try different tests in the car when your done if you want to max the combo out