Originally Posted by PR3CI5N
Must have went wrong on the install at some point or you're not on the correct map. The increase in power is noticeable as soon as you touch the gas pedal. I just installed a JB4 on a members 335i who didn't know much about the tune and he said the he noticed the increase in power immediately. Good luck
Got it installed at Eurowerks in Pompano Florida, they do great work. It was on Map 1, then switched to Map2 when I got my downpipe installed.