Well, I ordered this flange from ATPturbo.com last night around 5pm, arrived this morning (on a saturday... wow..)

Anyway, I noticed these three tapped holes... I can't figure out why theyre there... Would rather not pull my current downpipe to check... so can anyone tell me what they're for, and if I need to have them plugged for use with my T3/T4? All part of a greater plan to get my own 3" pipe fabricated...

FS: 2.5" Test Pipe 25 shipped

They're there to bolt your downpipe to... or you can weld your downpipe to the flange. Either way, the tapped holes are there for convenience.

yea thats what i thought

just a standard 3 hole flange that the muffler shop would have? hmmmmmmmmmmmm

i guess removing 3 bolts is easier than removing five... and less risk of stripping out the bolts inside my turbine housing

although theyd be kind of hard (impossible) to get at w/ the piping in the way

FS: 2.5" Test Pipe 25 shipped

I recommend welding the downpipe directly onto that flange. Here are my main reasons:

* space limitations in our engine bay
* fewer connections = less chance of leaking
* the five bolts are easier to access
* ease of fabrication

FS: 2.5" Test Pipe 25 shipped

You should still use it so the exhaust flows as smoothly as possible. Don't weld the 3" pipe directly to a 2.5" outlet, use the transition... that's the most important part of the exhaust when it comes to flow.

rreally... hm...

i'll make sure it gets in there then

FS: 2.5" Test Pipe 25 shipped

Those are some nice pieces of metal. This is what everyone should have been doing all along instead of messing with those fuck-o's over at ADFX.