Hi guys I had a question about the whole exhaust set up. I just want to know how it all comes together like I am looking at people getting up pipes and then down pipes and I am not sure if you need an up pipe if you have a down pipe? Is a down pipe just a better version of a up pipe? Thanks
Up pipe goes "Up" from the exhaust manifold/header to the turbo hotside, downpipe goes "down" from the turbo hotside to the catback. Up pipes on the earlier WRX's had pre turbo cat's in them hindering performance even further than the already restrictive up pipe, thus the reason most people with earlier WRX's replace both. Downpipe's are the real source of backflow issues for stage 2, which is the reason to replace downpipe's for stage 2. Hmm confusing post, bottom line no they are not the same.
Brfatal's diagram is for 02-05 WRXs only (Read: Does not apply to STIs or any other year WRX) Because it has the UP cat....eliminate the UP cat and it pretty much is what other years look like. Minus the silencer for the 08+ WRXs.
378awhp/373wtq Custom Dom 3 & CBRD tuned 2006 STI.
"When in doubt...flat out" - Colin McRae