RENNtech ECU Upgrade for S 550 | W221 | 402 HP / 405 LB-FT | MY2007-2010 audi-rs4--8k---2012-2015--4-2l-v8-fsi-esr2470407 0L V6 BiTurbo

0L V6 BiTurbo

CL (C216) 500 Blue Efficiency [2 Filters Required] (HP: 435 | Year: 10 > )

RENNtech inner fender housings are required

NOTE: Due to the increased size of airboxes the OEM engine cover must be removed

CLASS GL (X 164) 450 [2 Filters Required] (HP: 340 | Year: 06 >)

RENNtech ECU Upgrade for S 550 | W221 | 402 HP / 405 LB-FT | MY2007-2010 audi-rs4--8k---2012-2015--4-2l-v8-fsi-esr2470407 0L V6 BiTurboRENNtech ECU Upgrade for 221 S 550. Up to 402HP and 405 LB FT. Gains: +20HP & 14 LB FT RENNtech has been at the forefront of ECU tuning since electronic engine management started to show up in vehicles during the mid 1980's! Our experience, countless hours of in house research, development and exhaustive testing ensure that our proprietary ECU upgrade offers incredible performance gains and rock solid daily driver reliability. RENNtech tuning software