Why not use the dyno shops wideband to tune the AFR and then just forget it ?
As a real world example of how one can not simply “set it and forget it,” I’ll use the 4th generation (1993-up) Toyota Supra Turbo. I personally know of several of these cars modified with higher capacity fuel systems, larger turbochargers, and other components to support increased power. Included in such modifications is a “fuel controller,” an electronic device to tune the fuel injection pulsewidth (and consequently, the AFR) based upon engine RPM. Examples of these devices include the HKS GCC, HKS Super AFR, Apex S-AFC, and Field SFC, and are very common in modified, forced induction vehicles (especially imports). In the past couple years I’ve been involved with tuning some of these cars using both the wideband O2 sensor incorporated with the dyno (usually a Horiba brand system), and the built-in FJO wideband AFR monitors. In numerous cases we would get the AFR tuned nicely where we wanted it (usually in the 11.5:1 – 12:1 range at high boost) and call it a day. Then, later — perhap
