RENNtech ECU+ Upgrade | GL 550 | BiTurbo 4.7L V8 | X166 | 540 HP / 705 LB-FT | M278 Engine mercedes-benz-sl-class--230---2003-2006--sl-65-amg-esr5843963 Gains: +39HP & +20LB-FT

Gains: +39HP & +20LB-FT

The maximum power number reached with the RENNtech ECU Plus Upgrade for the R172 - SLC 43 AMG is 416 HP and 460 LB-FT

ECU+ Upgrade | Up to 783 HP / 798 LB-FT | Gains: +102 HP & +62 LB-FT

RENNtech M276 Biturbo ECU Upgrades are TÜV approved

623 LB-FT @2

RENNtech ECU+ Upgrade | GL 550 | BiTurbo 4.7L V8 | X166 | 540 HP / 705 LB-FT | M278 Engine mercedes-benz-sl-class--230---2003-2006--sl-65-amg-esr5843963 Gains: +39HP & +20LB-FTECU+ Upgrade 540HP 705LB FT Gains: +92HP +167LB 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