Loren

You won't find anything to bolt right up. It'll rumble if you open up the muffler a bit.

A bad tune can't snap the cambelt or make the clutch slip.

In general you would only notice a coolant smell once it is escaping from somewhere... in this case the overflow bottle. I would take some out of it (when it's cold)... if it still keeps overflowing, you maybe in trouble.

Alistair will build any motor for you... definitely not just race motors.

Maybe. You check the parts numbers here: https://jp-carparts.com/subaru/carlist.php?maker=subaru

Probably not. The evap valve should only open when the engine has vacuum and if the blocked line is going into the intake manifold... the evap valve opening won't do anything at all.

Not in that position I don't think... the boost control stuff is usually on the right strut tower... though I'm not familiar with turbo Legacys... Subaru likes to keep everything similar across cars of the same era.

Pretty sure that is the EVAP solenoid.

Well it could be the cause of your boost issues.

Is the EVAP canister still present and hooked up? Is it a turbo? Oh I see your other post... a twin turbo.

Evap system? Where does the other end go to?

Use "kneed it steel" or similar.

Yes they were KYB but (at least in NZ) there doesn't seem to be an STi specific model available. Not when I was looking for the same thing a while back.

You have had the same clutch since 2014? You must drive very sympathetically

Not saying you can't do fast takes off with the HD, but not full on rocket style launches... from my experience... it will just slip and make a big smell.

Don't go cheap with the clutch. Exedy work pretty well for me... I've used 3, 4 and 5 puk... 3 or 4 puk is more likely to hold up to launches, but not sure if available in NZ. The HD option is not suitable for launching even with standard power from my experience.

wet belts?

OEM won't be available. Part numbers for the struts are 20311FA900 20311FA910. KYB won't do an STi version.

You should replace the cam seals at the same time... you'd be crazy to not replace them, then find you have to do practically all the same work again in a few months because they have started leaking. There are a few good youtube videos on how to fit the cambelt.

You could close the gaps up tight to see if it helps. 0.018 would be as tight as you'd want to go.

What gap did you set? So coil on plugin is it? It sounds a bit like it could be mis-firing from what you have described. 4000 rpm is where the boost will be coming on very quickly, so peak torque... possible over boosting a bit and the spark is breaking down. Though I'm not sure how likely that is with coil on plugin.

I'd check the plugs and leads.

ok so looks like with the single avcs heads, those are biggest cams you can get without head modifications. I have the same cams and turbo but with the non-avcs heads. They are a good choice for the turbo, because the turbo is a bit on the big side for the motor. I am making 330kw with E30 and 27 psi boost... I seriously doubt it would make 400 kw with these cams... they are aimed at throttle response and not high rpm. What size turbine housing do you have? And it's not bigger ports you need for the higher lift cams... you just need some metal removing to allow for the larger lobes to rotate without hitting things. I would get it done if you really want 400kw. It's not a lot of work in the grand scheme of things and you could do it yourself with just a dremel. You should think about drivability before deciding on what cams... is it a track only car or something else?

You can go bigger to bigger cams before you need to modify the heads... but you'll need shimless buckets most likely. The turbo choice is going to be more important than the cam choice.

gloss would look bad imo.