Once plugged into the OBD-II port, we ran ESS Tuning’s E-Flash software. The user interface is very user friendly and takes just a few clicks of the “NEXT” button to link the software to your specific ECU. You download the OEM programming to be able to convert it back to stock later, then click ‘Program ECU Memory” and find the software file that is either included or emailed to you. ESS can modify and edit different features or change parameters based on the customer’s needs, like a CEL removal for Test Pipes, which we will be doing later on.
Once downloaded, simply plug the cable into your laptop and OBD-II port and run the file. Uploading the tune takes only 6 minutes.We had ESS update the base software from the 220E that was on our car to the most recent 240E spec, as well as remove the top speed limiter and the cold-start sequence that makes the car sound like a rough-running rattle trap on start-up. Their software involves a lot of changes to the timing, AFR, VANOS, throttle control, torque management targets amongst other parameters to reliably eke out a little more power than stock.
After the software was installed, we turned the rollers once again and were amazed at the results. ESS claims a 10-15whp gain but we put down a whopping 361whp @ 8,000rpm and 260 lb/ft of torque @ 6,900rpm. An increase of 24whp and 19 lb/ft of torque from a tune alone!
The ESS E-Flash tune alone netted us an impressive 24 whp and 19 lb/ft of torque gains.While our peak torque shifted from 3,900rpm to 6,900rpm, the torque curve of the S65 is extremely flat over the entire rev range. The new tune shifted the entire curve up to average a 19 lb/ft gain across the board with a maximum gain of 32 whp and 25 lb/ft at 6,812rpm. This greatly improves the area under the curve and gives a seamless improvement that mirrors the characteristics of the factory tune without any humps or dips that would detract from the perfectly linear and smooth power delivery of the S65.
With a maximum gain of 32 whp and 25 lb/ft of torque, the ESS E-Flash tune improved the performance of our highly-stressed S65 across the board with the OEM cats and mufflers still in place. For a simple tune, we should now be at ~440 hp at the crank, which is the same power as the 4.4L M3 GTS! (BMW’s answer to the 911 GT3).
