Alright.

I am currently building 2 Evos, an 8 and a 9.

The 8 is a 2L running a blouch dominator 1.0XTR.
The more detailed look:
stock crank
manley TT rods
wiseco 9:1 pistons
manley springs,
comp 280 cams,
mil.spec 65mm tb,
strictly modified intake,
STM exhaust manifold,
RC1200 injectors,
walbro 450,
I think thats about it for the important stuff.

The 9 I am yet to even begin, but, plan is either a 2.0L and a BBK-B, or a 2.3L (same turbo) I can list the planned build if needed.

I have multiple O2 housings on hand. A megan, an Invidia, and a MAP 3" Vband and downpipe.

For the current car on stands, the 8, I am debating if I should run the Invidia/Megan or run the MAP 3"? I am trying to debate if this one is going to have a flow rate high enough to necessitate the bigger outlet, or, should I save that for the larger turbo on the next car?

Thank you for any insight people can offer here.

 

You're not going to be power limited by the O2 housing in either of those setups.

My car makes north of 600whp with a standard open dump O2 housing.

 

So, you have been running a regular aftermarket unit at that power level with the 2.5" opening? thanks again.

 

People have made great power with those or similar o2 housings on similarly sized turbos. I don't think it will be enough of a restriction to significantly compromise power short of a dump

 

Yes.