Cheers lads I'm asking because I want to put a down pipe on the car and was told I would need a boost controller cause of over boosting is ok to put a down pipe on the car without a map or why does it need a map
Map would be necessary... And your kind of answering your own question as in it'll overboost... Boost controller would regulate boost but not air and fuel ratio... And downpipe would cause it to not be fueling right either.