I used the old Works 3" O2 Housing with no divider (Bell Mouth) and their 3" down pipe. Didn't seem to upset tune (MAF tune). Never dyno tested. Parts no longer made.

Suppose you're right as I've heard the early boost/torque of the Evo 9 is actually not great for stock rods.
I'm just kinda torn between a full rebuild, a rod job, or just send it as is. Have to take the head off anyway for ARP studs and fresh Evo 9 headgasket, cams and springs.

Here in New Zealand, engineers don't seem to be keen on machining the pistons for aftermarket rods, instead they just keep telling me I need forged pistons and not listening to the concept of OEM pistons.

Appreciate the feedback, other than spool, does it feel much different?

As an engineer in America I would suggest listening to the engineers in New Zealand.

This is the first time I heard someone trying to reuse the stock pistons with aftermarket rods. I dont understand what you are trying to achieve but from my POV its seems like a bad idea.

Rodjobs are pretty common in the Evo community, most seem to have great success retaining OEM pistons and upgrading the weak rods to something stronger, only machining required to the piston is circlip grooves for the wrist pins as the factory wrist pins are press fit into factory conrod small end.

I wanted to do it to avoid boring and using oversize pistons, as well as keeping factory piston to wall clearance. I don't like how forged pistons rattle on cold start and breathe more.
I Know this isn't always the case but it seems more common than not.
My goal isn't massive, but i feel it'll be on the limit of the stock bottom end

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O for sure, but you know how people get when they are getting a tune.
Make it spool faster, 1 more psi, why does it make so little power lol

Just wanted to throw it out there so he could think about the actual goals for the car as opposed to keeping the stock turbo for ?? reason.

Then get standard sized 4032 alloy pistons. They don't expand nearly as much as 2618 alloy so can run a PTW that's just a bit larger than stock and are perfectly fine for mild goals. Stock pistons are much less knock tolerant than a forged piston, there isn't much reason to stay with them. Hell after paying a machine shop to machine a set of stock pistons you're probably halfway to a set of forged pistons in cost anyway.

Forged pistons don't rattle if your machinist doesn't suck, and you choose a quality piston (wiseco 1400hd, hint hint). I build about 20 4g's a year. Not a single one rattles the pistons on cold start. Even the high power ones at .005" PTW.

Since there doesnt seem to be many Artec threads, does anyone know how this manifold is compared to the FP race manifold?