RENNtech ECU Upgrade Z4 35i E89 (2008-2012 N54B30) mercedes-benz-cls-class--218---2015-2018--cls-550-biturbo-esr2270978 and four exquisite tailpipes

and four exquisite tailpipes

The shocks arrive with settings for Street or Track

RENNtech is the foremost authority on transmission upgrades and has done countless rebuild and upgrades for the most demanding dealers and clients for over 21 years

and resonant

RENNtech ECU Upgrade Z4 35i E89 (2008-2012 N54B30) mercedes-benz-cls-class--218---2015-2018--cls-550-biturbo-esr2270978 and four exquisite tailpipesRENNtech ECU Upgrade Z4 35i E89 (2008 2012 N54B30). Up to 420 HP + 435 TQ. Gains: +120 HP & +135 LB FT Our proprietary BMW ECU upgrade offers rock solid performance from RENNtech, the foremost tuning authority on Bosch and Siemens engine control units. These same units are utilized in Mercedes Benz vehicles, which RENNtech has been tuning since electronic engine management started to show up in vehicles during the mid 1980's, though our proprietary