RENNtech ECU+ Upgrade | C217 | S 550 Coupé | 540HP / 705LB-FT | 4.7L V8 BiTurbo | M278 | MY2015-2017 mercedes-benz-amg-gt--190---2018-present--gt--2018-present--esr3206634 RENNtech Track Series RTS |

RENNtech Track Series RTS | 19 in

CLASS S (W 221) 500 [ONLY USA] [2 Filters Required] (HP: 387 | Year: 05 >)

especially within the important RPM range between 5

RENNtech ECU+ Upgrade | C217 | S 550 Coupé | 540HP / 705LB-FT | 4.7L V8 BiTurbo | M278 | MY2015-2017 mercedes-benz-amg-gt--190---2018-present--gt--2018-present--esr3206634 RENNtech Track Series RTS |ECU+ Upgrade 540HP 705LB FT Gains: +66HP +139LB FT RENNtech HHT (hand held tuner) allows you the unlimited ability to switch between tuned and stock ECU programming and requires no ECU removal! Our proprietary tuning module stores both the RENNtech tuned file and your vehicles stock file. The module plugs directly into the OBD2 port and delivers the file you choose directly to the ECU. Programming takes only a few minutes and the vehicle can be