a few things-

Phil there is no such thing as a calibrated "hub dyno".

There are typically 3 different variations of them.

Group1.) dynos lower then the typical dyno-jet.

Group2.) dynos relativly dead on with typical dyno-jet.

Group3.) dynos higher then the typical dyno-jet.

These are all "calibrated" hub dynos. It just depends when they were made and what calibration they used. As if you wanted you could have a new (ie produced durning a different time period) dyno-pack calibrated to what your old dyno was calibrated at. (shawn Church of Church Automotive had this done.

This is backed up by real world testing. Locally we have a dyno-jet and dyno-pack that read fairly close to each other. (within 2%)

At NASA nationals a dyno-pack was rented by Shawn Church so that he could dyno some of his customer cars and make sure their tune was good. Modular depot also had there dyno jet there. Three of the cars we were paddocked around/are freinds with ALL dyno'd HIGHER on the Modular depot dyno-jet, then they did on the Dyna-pack. Roughly 10% to 15% higher.

Dyna-packs are great for tunning, but are rather inconsistent from one machine to the next.