They allow for fine tuning of the fuel/timing/boost curves to extract the most hp out of your vehicle. They can also provide such things as launch control, shift light triggers, nitrous solenoid triggers, etc, etc....
Basically, they give you more than enough tools to blow up your vehicle if you don't know what the heck you're doing.
The AccessPort doesn't do that...
Nor does it provide for any of those...
The Accessport allows loading modified engine operating parameters (collectively known as "maps") that are written by Cobb Tuning. The maps are user selectable, but the map content is not---it's a "set it and forget it" deal.
The concept is to provide the end user with a completed package that will render improved performance and reliability, with minimal attention & tweaking by the end user...not the absolute maximum possible, but not risking the engine, either...an analogy might be investing in a S&P 500 index fund, versus making your own picks of individual stocks.
Mo info at
UTEC sounds more like what you're talking about. There's a few others that allow greater control/gains/risks, as well.
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