Car enthusiasts don't risk the health of a motor for no reason, its almost always $$$ related.
As already mentioned on here, its tuners that charge $1k for a full tune on a PFC, and 400 for a "touch up" that make people more content to hang on, and wait till they get [insert here] until properally tuned.
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Edit: Realized i only ranted the hassles I totally agree in finding a good tuner, to help progress the development of your setup. Although it can rack up the costs a little, your not always going to get charged that same amount for touch ups I think one should try to tune the best combination out of each specific setup; it would give the best comparison of "which mod changed which feeling" which builds a better a understanding. Remember, a smokey farting, stalling import, isn't what its all about.
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Dyno more abusive then the road is a crock. WOT at a constant RPM while tuning a load point maybe, but i would think having wind resistance, and a constant 70% throttle position in 4th gear up a slight hill would constitute more "time accumulative load" or "engine damage"