I know back even just a few years ago, when you modified a car slightly, you really only had to tune it at full throttle. Under part throttle applications, the closed loop control between the MAF sensor and the O2 sensor would keep things in check. You really only had to concentrate your tuning at full throttle, because that is where the engine would go to open loop, and if your mods allowed the A/F to get out of whack, then you were not getting the most of them, or at worst, could cause damage...
So I know there are still gains to be had with custom tuning around extracting the most power, and drivability, but the question is with tighter and tighter emissions regulations, do cars still go open loop when at WOT?
So I know there are still gains to be had with custom tuning around extracting the most power, and drivability, but the question is with tighter and tighter emissions regulations, do cars still go open loop when at WOT?