Originally Posted by synolimit

Yeah it's custom.

Not really matching. The TB is 2.48" at its smallest ID point. On that is Z1 post tubes which go around the TB and any 2.5" OD pipe so I'd say their ID is more like 2.6". The sections of 2.5" OD pipe (like stillens cai) and oem MAF section are only 2.35" ID. Then like the MAF post tubes there's more silicon sections that will be 2.6" ID. So it's basically a roller coaster from start to finish.