[RKDinOKC]

The Programable chips are only $100. The box that interfaces with them and the tuning software, called SharkTuner, is $900. And the wideband O2 sensor so I could see what was going on was $138. It'a a good setup. You turn off and zero out the ECU's learning map and closed loop adjustment, then drive around data logging. Then you upload the data logs into a diagnostic plotter app and it edits the maps for you to match target fuel ratio and ignition timing (uses the knock counter to add/remove timing. Then you upload the new maps to the ECU and re-enable the learning maps and closed loop mode. You can run a 928 without monkeying with the fuel and timing maps because of it's closed loop learning stuff, but the less the car has to adjust on the fly from the basic maps, the better it can adjust for things like gas quality, temps, and humidity. Even a stock car runs a bit better with custom set maps than the stock one map for all conservative average.