Chezedik wrote:It is a flange, mechanically it is unimportant. The extent of it's job is to be flat and have bolts run through it. If the metal is of reasonable quality we are talking about a good with infinite substitutes. So yes, this is an area where I can afford to go cheap.
Simply because it does not have moving parts, does not classify it as unimportant.
In case you have not noticed, the port profile is no simple shape. It is more of a kidney. Not to mention you must have proper clearance for the wastegate flapper, if you intend to use the internal wastegate.
Furthermore, all this must be as closely milled to the original as possible. As there is little clearance for nuts/washers or bolts when you weld pipe to the flange.
Trust me, this piece is important.
Listen, bottom line, I'm not trying to come off as a prick.
I run a Z31 T3, and having fabricated and machined everything myself, I know what is critical, and what is not. I know what to look out for.
Many people have struggled with this flange, and you would benefit from heeding other's experience.