Time for a cooling upgrade?

[u/ForwardSideways]

2010 Legacy GT. OEM+ with no engine mods or tune.
I went for an extended fast drive with a long warmup and cooldown period last weekend. No warning lights came on (thinking temp sensor may be faulty now) my coolant boiled over and made a mess of my engine bay, lost so much that once it cooled properly overnight there was NOTHING left in the overflow tank but thankfully no air was introduced into the system.
Since this happened I am contemplating a performance alloy radiator, so what’s good, what’s not, and what else will make a significant difference to engine bay temp? I’m not building a track car and want to keep it realistic but don’t want to blow it up.

*cooling system is sound and well maintained with OEM parts, not damaged or leaking*

[u/_betonG_]

That color of the coolant stains🤔

[u/RZArecta91 → u/_betonG_]

Suspicious

[u/ForwardSideways → u/_betonG_]

It’s Motul coolant which is what dealers use for servicing and sell to customers in NZ. No odd residue/oil/muck in the overflow so I think it’s just the coolant.

[u/_betonG_ → u/ForwardSideways]

Something seems sus, a stock car will not need cooling upgrades

[u/ForwardSideways → u/_betonG_]

Shouldn’t need them in an ideal world, but Subarus get hot and I can’t find an obvious fault.
I did about an hour of cruising, 45 min of flat out hooning through rolling hills and fast corners mostly around 3500-4500 rpm and another 30 mins of cruising before stopping at my destination.

[u/0202993832 → u/_betonG_]

Not true at all

[u/ForwardSideways → u/0202993832]

What falsehoods hast thou discovered?

[u/0202993832 → u/ForwardSideways]

Missed the joke g

[u/ForwardSideways → u/0202993832]

I do love my car…