boon

If that's a TD05 on pump gas I'm a banana. It spools slower than my Holset, and pulls out to the redline. If their version of a "TD05 Hybrid" is a TD06 compressor wheel and a TD06 turbine wheel then it's a TD06.

I'm not sure that the compressor housings would swap over, isn't the 22 compressor wheel larger than the 28's? The resulting gap between the housing and the wheel would surely result in a loss of efficiency.

I would speculate the AFM is failing.

The cheapest per kw option is probably still my twisted setup And then you're T3 flange on the uppipe and if you wanted to change turbos down the track all you have to do is modify the downpipe to suit, will support anything up to about GT35 frame so somewhere in the realms of 450-500wkw. EDIT: Seriously, as an "on a budget" option without wanting to piss your money away if you upgrade in the future it (in my mind anyway) makes a fair bit of sense. In hindsight the turbo probably isn't perfect but with a front mount it should get you bloody close to 280wkw with reasonable spool, and it's built like a brick shithouse, plus down the road if you're feeling flush with cash and want to change to a BorgWarner or a Garrett GTX it's a relatively simple change, and you will easily find someone you can flick the turbo to as it would go bloody good hanging off a SR, RB or 4G63. If my new turbo wasn't v-band on both sides I would have just sold the turbo and used my existing setup but it seemed dumb to cut up what was a pretty expensive custom fabricated turbo setup.

Legacy headers require changing the sump, baffle plate (I think?), pickup and dipstick. Not a difficult job, just a nasty messy one. Legacy headers (or the much rarer STI ones) + a twisted adaptor + a twinscroll BorgWarner EFR7163 with internal wastegating is probably the simplest way forward that delivers most of what you want. If I were to do it all again with my car from square one it's what I would be doing. Not cheap though!

I guess so. It just makes me scratch my head when I see these schizophrenic cars being built. As an example I love car audio to bits, I used to be crazy into it, SPL setups, sound quality setups, you name it, I've probably done it. What does my STI have in it? A bluetooth headunit and the stock speakers. The car is just too loud, both from the engine/exhaust and road noise, for there to be any point in me putting a decent stereo in it. It would be wasted money. I could put a quieter exhaust on it and sound deaden it and put on some tyres with softer sidewalls but the point of the STI is, well, none of those things. You can compromise on things and make the car a mediocre jack of all trades but all you will end up with is a car that's a bit S*** at everything, unless you have insane amounts of money to throw at it. The extreme version of this would be lifting a Ferrari for better off-road performance. As you've said each to their own but some stuff just doesn't make sense to me.

Totally unrelated but where did you get the flange for the twisted adaptor from? Need one for my own silly plans.

Respectfully disagree, anyone who is busy putting adjustable coilovers and aftermarket engine mounts and roof scoops and deleting their air con.... isn't trying to build a smooth and sensible daily. If you want that, buy a H6 Legacy. Or a BMW. A stock STI is a S*** platform for a nice comfortable cruiser. The best driving experience from an STI they ever built is an early RA and that's because they're raw and noisy and a bit feral and they have the slowest spooling setup of any STI. A GD STI only has a meaningful powerband of about 3000rpm before the stock turbo goes off a cliff anyway, probably less than that in terms of the torque curve. Doesn't matter if you're in an STI or a 1.5L carbed Civic, if you're giving your car beans anywhere that isn't the track or back roads you're probably a bit of a tool anyway, so that's a moot point as well. I couldn't give any F***s how my STI drives in stop-go traffic, because if that happens then I've had some sort of S*** day that doesn't involve the size of my turbo.

Read this: https://jalopnik.com/dear-automakers-please-stop-making-turbos-suck-1688464610 Big laggy turbos are the best You have 6 gears, use them

I made 231wkw with a VF34. This seems to be about the limit of the VF turbos on pump gas. To answer your questions... -I used the standard internal wastegate, an external might help just a little with boost control but won't make a huge different to power output. -I just had stock V7 565cc injectors and I think they were almost tapped out. You will probably have 440cc ones - unsure if they can be decapped? -I would be upgrading the fuel pump to one of the nice in-tank options, I used an Aeromotive Stealth. Stock FPR and fuel lines etc. -Yep G4+ is a great option -I did all of this with a stock V7 blow-off valve -You'll probably need a V7+ top mount, or a front mount. -220wkw is probably the limit on a VF28

Off the top of my head you would need to change a hundred bucks or so worth of oil lines and there might be another couple of hundred bucks worth of misc stuff like relocating the coolant tank thing. But you would still be in the ballpark of just buying the other turbo. You're gonna need a bigger intercooler which ever way you slice things; the HDI front mount one that @Batbaruman got is probably a good bet - there's 2 models so make sure you're getting the right one.

The simple answer is my twisted setup which is cheaper than both the DPR and PBMS turbos.... do you already have a front mount?

Time for some quick maths - a TD05-20G will flow about 45lb/min at the very edge of it's map. Using a solid rule of thumb of 10hp/lb you get a 450hp turbo. Making ~337 flywheel kilowatts; applying typical Subaru drivetrain losses I get 250wkw. Which is pretty typical of a TD05 run to the ragged edge.

A TD05 that spools like a VF and makes 275kw is more commonly known as a BorgWarner EFR and has a whole lot more technology in it than the trusty old TD platform. Seriously, I have a feeling those conditions are mutually exclusive unless they're sprinkling a whole lot of magic dust on it.

Check the fluid level, but yeaaaaah it's a 28 year old car, how many kms? Possible that the box is on the way out.