hey i have a s4 TII manifold sitting at home to for my 12a turbo project and i was thinking about something and it makes me uber curious.


ok here... can you guys tell me what the hell is the purose of this hole?

in case your wondering ive made an adapter to bolt the s4 manifold to my 12a that consists of a 13b flange and a 12a flange welded together by 2 1/8" of heavy wall pipe...so i already welded up this hole cuz frankly i didnt know wtf it was doing there in the first place i also removed the twin scroll and welded it

oh and this pic is not mine i just stole it from some forum member cuz im at work and cant take a pic of my welded up manifol

 

EGR port, judging from the position.

 

The 6 port 12A manifold also has that. I assume it is for aux port activation. The EGR port is on top of the intermediate plate on both engines (6 port NA). What that hole is doing on a turbo mani, I couldn't tell you. Probably an S4 thing.

 

correct. on the s4 t2, usa spec, the egr comes from the manifold, goes into something and ends up on the back of the intake manifold.

 

huh egr i guess i never figured it would be for that...well with my 13b to 12a flange i made that hole is completley pointless

thanks