2005 STI blow through
I also made a 3″ blow through MAFS cold-pipe for a 2005 Subaru WRX STI with a Blouch 20g and a nameless FMIC. The original cold pipe was 2.5″, and as you should know—that isn’t enough resolution for even stock power with a blow through MAFS. While 2.75″ is closer to stock, it starts to lose resolution at 400-450 hp. 3″ blow through MAFS have a very high power limit but are hard to tune for drive ability, Nick being the freakin’ tuner genius, seems to get by with a 3″ MAFS.
The best part about it: it fits better than it did before, and it is a full 1/2″ bigger diameter!
Some sample welds:
