Originally Posted by Longboarder
Actually there have been zero catastrophic failures due to tunes on the n54 or n55's. The DMEs are very sophisticated and intervene way before there would ever be a problem. There's even cases where guys have run meth and tune for it...with no failsafe...and when meth stops flowing, the DME adjusts! Try that on a EVO and you have a blown motor. Maybe Shiv and Terry are terrible tuners...I don't know. But maybe they don't need to be good since the DME is so good.
It's your car, you can do as you please. As for the DME intervening to prevent failure - if that is happening, it means the car is tuned way too aggressively and the car is saving itself. A good tuner should be able to safely tune for all circumstances without needing to rely on the factory safeguards. If what you are saying is true then all tuners should produce about the same results as everyone can just max out all the values for the given mods and let the car handle the rest.