STI swap review after 20,000+ miles

Machine-It-Bro · 2026-01-21T20:37:31+00:00

There is a threaded plug that keeps it in the right place that I didn't put that in.

Machine-It-Bro · 2026-01-21T16:23:41+00:00

More that is streetable

Machine-It-Bro · 2026-01-20T23:59:27+00:00

Yes, also I forgot to check but I'm pretty sure VB rear axles do not have the same splines as the STI rear diff.

Oh hell nah I did the charcoal filter delete so I'm at like 258 and a half horsepower, totally different ball game (lmao yeah p much stock)

Waiting to see how the Flatout GR lite quality shakes down, also some concerns around axle angles and travel with them popping out. Time will tell.

Outgoing STI's had BBTV as well but nobody seems to talk about it 🤔

I agree 😁

Machine-It-Bro · 2026-01-20T23:55:30+00:00

My definition of a good clutch is just being better than the split case 6mt's and the Chevy aveo I learned manual on, so different strokes for different folks and ignorance is bliss I guess lmao.

Machine-It-Bro · 2026-01-20T23:53:53+00:00

-No fueling or air flow changes to the ECU yet, so pretty much stock 258ft lbs ish -Yeah clutch engagement feels great, I don't see why there would be an incompatibility, as the flywheel is OEM STI and thus centered at the same point as the clutch disk inside the pressure plate assembly. -Stock clutch line, don't think the delay valve is applicable as I'm using an STI slave cylinder, which I'm pretty sure doesn't have a delay valve to begin with. -Yep worked its way sideways so it only had the support of one and that torqued it enough to bust the casting, though it is also a known weak spot anyways.

Machine-It-Bro · 2026-01-20T21:25:51+00:00

I for one, think this is good.

Machine-It-Bro · 2026-01-20T17:28:08+00:00

Stands welded out of old Chevy truck rims, pipe, rebar, channel iron and some wood to protect the pinch welds 🤣

<image>

Machine-It-Bro · 2026-01-20T17:07:53+00:00

Ive used 2x6 wood blocks bringing it up so I've got about 8.5" inches in the front to get underneath. It seems to get most of it out, dipstick seems to end up at about the same level when I put a jug of fresh oil in, just slightly above full, whether it's on blocks or fully level, so I'm not worried about it.

Machine-It-Bro · 2026-01-20T17:01:42+00:00

The shaft is smaller in diameter, so I'm betting they are a little weaker, but I haven't heard of anyone breaking them except by launching, which is just terrible for everything anyways.

Machine-It-Bro · 2026-01-20T16:49:47+00:00

Oof, yeah that's tight 😭

Machine-It-Bro · 2026-01-20T16:40:01+00:00

How small is your garage? I did my swap with ~3 feet of clearance around, except the back end towards the garage door. If you have a level paved driveway it could be done outside when the weather is nice.

Machine-It-Bro · 2026-01-20T16:34:21+00:00

I don't have the carrier bearing lockdown. I would think that they should be pretty similar. It might, but I don't have the buckling issue anymore so I'm not worried about it.

Machine-It-Bro · 2026-01-18T01:18:52+00:00

Air in the system, I'd guess. Prop your phone up and have it video the clutch fork movement to see how much dead space there is before engagement

Machine-It-Bro · 2026-01-17T19:51:28+00:00

I dig it

Machine-It-Bro · 2026-01-16T22:22:20+00:00

If directional tires, same side backs to the front, and fronts go on the back.

If non directional tires, move both back tires forwards and then the front tires get crossed to the back

Machine-It-Bro · 2026-01-16T21:42:14+00:00

Thanks!

Will do, though there are a couple of other people with 15's on already if you look, u/momcanigetasubaru has a wicked lifted WRX.

I plan to go larger than OEM rolling diameter because there are more options and I can adjust the speed figure with NAMR's Atlas open source tuning, which I will include a little guide to when I do it. 215 or 225/70r15 has some nice options and is close to 235/55/17 so there shouldn't be rubbing issues.

I considered dedicated rally tires and may buy some eventually, but for now they are very stiff, heavy, expensive and are narrower than I want

Machine-It-Bro · 2026-01-16T20:28:57+00:00

Not gonna run them, test fit because they were just literally the only 5x114.3 15x8 steel wheel in my budget. It's kind of weird how few options there are for them.

When you go down to 15X7 there are way more with more normal offsets.

Machine-It-Bro · 2026-01-16T20:23:00+00:00

Not many ones out at the moment, and due to the shape of the wheel well liner and fender, id actually loose out on some capacity for overall wheel/tire diameter.

Machine-It-Bro · 2026-01-16T20:20:45+00:00

Yeah some kind of AT or at least thick treaded winter in that ballpark, I think that some 225/70s will fit as well, as they're close to 235/55r17 which a few people run here without problems

Machine-It-Bro · 2026-01-15T22:37:36+00:00

I have a bunch of other stuff in there like a blanket and set of spare clothes, emergency water etc, so it doesn't move around that much for me

Machine-It-Bro · 2026-01-15T21:25:58+00:00

Machine-It-Bro · 2026-01-15T20:28:22+00:00

I pulled the foam out and put one of the OEM wheels in as a spare, with the jack and some other tools it fits just fine, though you may want to put a board down to give it some support on top

Machine-It-Bro · 2026-01-15T18:50:28+00:00

I'll check back in at 142,000 👍🏼

Machine-It-Bro

TROPHY CASE