RENNtech ECU Upgrade Z4 35iS E89 (2008-2012 N54B30to) audi-tt-s--8j---2006-2014--esr8173231 Gains: +21HP & +36LB-FT

Gains: +21HP & +36LB-FT

0" | Rear: 21" x 10

The tubes have to be returned in good condition

mounting directly to the OE down pipes - and all RENNTECH headers are hand built from mandrel-bent

RENNtech ECU Upgrade Z4 35iS E89 (2008-2012 N54B30to) audi-tt-s--8j---2006-2014--esr8173231 Gains: +21HP & +36LB-FTRENNtech ECU Upgrade Z4 35iS E89 (2008 2012 N54B30to). Up to 420 HP + 435 TQ. Gains: +100 HP & +103 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