Throttle Body Swap
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I was wondering if I was to switch out my stocker, what parameters would have to be retuned? I had someone tune my cammed idle, and I don't want to mess with it, so would a ported or aftermarket TB change the idle? Do you usually have to add fuel too? Thanks.
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There's a table or two that reference desired vs. actual airflow in grams/sec. The tables convert that data to 'steps' for the IAC, which is what opens/closes your TB blade when your foot is off the gas (to control idle rpm). When you drill or port your throttle body, this changes how many grams/sec are equal to the factory programmed number of steps. Therefore, the IAC thinks it is supplying less airflow than it actually is. This causes slight surging/hunting for the right idle speeds, which can also cause the car to stall.