sorry to wake this thread back up again guys... i spent almost 2 hours on a mustang this afternoon, and made some somewhat interesting observations.
after reading this thread before going into dyno my truck on its current build level(and having only used a dynojet before), i was definitely skeptical about the accuracy of the numbers i was going to get after the smoke cleared this afternoon.
load dyno's have a lot more to offer, and thats a fact. i agree 100% with ramtd02 and crzycoyboy about dynojets being 100% fool proof. its hard to screw up using the dynojet; though it seems like some shops think that you should be in 1:1 transmission gearing, while others believe that you should be in highest gear. the arguements have been made and both are legitimate, and its understood that our f-in-huge turbos have a hard time lighting if there is no resistance.
now that ive spent the time on the mustang, i see why numbers *CAN* and *DO* fluctuate so much. the mustangs are far from idiot proof, and definitely not user friendly, it seems. they have a plethora of settings and parameters that need to be filled for each vehicle individually, and take a lot more into consideration. while i was tinkering with my programming, the dyno operator was tinkering with his programming, so that after almost 10 pulls, we finally matched as far as a fair measurement, where the roller resistance values were correct(not too tight or loose) and we were taking readings from the correct gear, at the correct wheel speed, correct RPM. i could see how an inexperienced operator; or even an experienced one with minimal computer skills will constantly have issues being able to make their dyno credible; and my experience today was definitely proof to me of this. the options available within the software are almost as abundant as in my high $$ A/V editing software on my computer(that took me over a year to finally learn all of the tricks it had)
i believe that the mustang has the ABILITY to be a lot more accurate, reliable, and consistent, but their operators need to be trained a whole lot better; or the mustang software needs to become more user friendly. it looks like ill be off to another 1 or 2 different dyno's to check the accuracy of my numbers... nonetheless as it stands, im totally happy with how my truck performed today and what i got for numbers.