I tried to dyno my 2002 4.6is a few years ago right after I installed the S/C. It was an 4WD dyno in the Bay Area but I can't remember the name of the place now. In getting the X5 prepped to go on the rollers, I wasn't too impressed by the young guys doing the dyno. In any regard, the problem I encountered was not being able to disengage the DSC completely. Even with the button off, DSC will still activate to a certain extent. I couldn't find the correct fuse to pull either. Secondly the X5 rocked so bad on the rollers that it was losing traction and activated the DSC. I have a video of the dyno but will need to find it.