I had my XSport run on a non-linked Dynojet. The tech ended up pulling a fuse(s) from the power distribution box (under hood) to disable rear drive, because even with traction control disabled (via the dash menu), he said he could still feel the ABS/stability control pulsing when he got over a certain speed.
Not sure what they are on the SHO, but on my XSport, I believe he pulled all of the ABS related fuses: Fuse 5 (50A Anti-lock brake system pump), Fuse 43 (40A ABS valves) and Fuse 92 (10A ABS module, Plant EVAC and fill). Do this at your own risk; I'm not sure of the consequences of running in this condition.
Once these fuses were pulled, there were terrain management and ABS errors shown on the dash, and it disabled rear drive.
They sent me on my way with error codes and ABS warning lights saying it should reset after a few key cycles. I got home and found they forgot to replace Fuse 92 for the ABS module. Once I replaced it, everything was back to normal. No more Late Model Throttle in Waukesha, WI for me, LOL. The following day, I ran on a linked Mustang dyno (Endless Autosport in West Allis, WI), and ran with zero issue - no fuse pulling required.
Moral of the story: Linked dyno should alleviate any issues. However, if you remove fuses to do your pulls, you will get a bunch of warnings on the dash, but they should resolve (immediately) once everything is back in place. Don't leave the shop unless you are free from warning lights and have confirmed everything was properly reinstalled.
