I have a feeling this question has been answered before but I cannot find it. What STI donor parts will not fit the 818?
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I have a feeling this question has been answered before but I cannot find it. What STI donor parts will not fit the 818?
It has been covered, but I will help, 04 5x100 sti hubs will fit, but 05-up 5x114 hubs won't, the six speed won't fit at this point. I might be missing something, but nothing major.
818S frame #13 Jdm version 8 ej207
brakes are an iffy thing, depending on what knuckles you get, the sti Brembo's will or wont fit, also depending on if they are 04 or 05+.
steering rack is quicker, has different mounts 05+, beyond that. there's not much.
02-07 WRXs and Sti front brakes are interchangeable. The brakes all have the same mounting holes. For brembos you'll need 04 STi rotors which are a 5x100 pattern, but it is done all the time. The rears you will need conversion brackets. 06-07 wrx and sti rear brakes are interchangeable with no such bracket. The lug pattern is different for wrx-sti 5x100-5x114 05-07. If you need advise I got ya.
818S frame #13 Jdm version 8 ej207
I was about to ask this as well. A guy here wrecked an 05 STi Spec-C that I was considering putting an an offer in for the whole car but decided against it.
If I ran across a good STi donor for a good price, I'd take it. I'm sure SOMEONE on the internet would happily trade you their 5-speed for your 6-speed! And you could always buy (or trade for) the appropriate hubs...
+1 Xusia.
818S frame #13 Jdm version 8 ej207
Why wouldn't the hubs work? What's the differences between wrx and sti hubs besides the bolt patterm
A little off topic what years and model had the aluminum lca's
That's the only year for the WRX, but didn't several years have them on the STi?
As far as I know all of the sti's had aluminum control arms but I was only answering for the wrx
usdm 06 wrx, all usdm sti and many jdm wrx and sti, heres my new ones from spt performance securedownload-25.jpeg
818S frame #13 Jdm version 8 ej207
ONLY the 06' wrx Sedan has the aluminum control arms. Wagons still got the steel ones![]()
1998 Subaru Forester
Full 06' STI conversion
Twin scroll low mount headers
HX35/40 turbo, ITB Custom intake manifold
Also, the caster is different between the STI Aluminum LCAs and the WRX ones FYI (STI have more)
The caster difference shouldn't matter on the 818 as the upper arms look to be fully adjustable.
For the most part, you can get an STI as a donor and just plan on swapping the transmission for the 5 speed. The 6MT is worth far more than the 5 speed and Forester, WRX and Legacy GT guys buy used STI transmissions to swap in all the time.
All you would need to do is modify the axles to use the correct WRX front inner spline into the STI rear hub output spline. OR you could trade your hubs and brakes for WRX ones.
The Transmission trade and the brembo trade would net you some cash on top.
Just to add to What Brandon said above...
If your STI is '05+ then you will also need non-STI front knuckles OR modify the FFR provided upper A-arm adapters to fit the STI knuckles.
Can't say without seeing final production 818 parts.
The 'riser' from the hub (that the strut bolts to) on the STI ('05+) is thicker than on a WRX. The spacing and locations of the 2 bolt holes is also different.
I'll probably just go ahead and grab everything now, I already bought the Brembo brakes, I can get the rest for free from the same car. Hopefully by next April when I get mine someone will have figured something out. If not, guess I'll have to be the first.
Thanks for the info.![]()

First the top hole needs to be welded and then the sides need to be machined smooth to the wrx width. then the top hole is redrilled to the wrx pattern.
example of a modified knuckle:
5x100_1_0.jpg
A well stocked beverage fridge is the key to any successful project.
Interesting, thanks for that picture, this thread is proving quite useful. I really appreciate all the help this forum has provided. Thanks!

If you have an endmill and a welder you can do it yourself. The holes are redrilled in the same plane so scribe a line and then just cut the bottom off an old wrx strut to get your measurement.
A well stocked beverage fridge is the key to any successful project.
That's beyond my skillset and equipment. But I'd be more than happy to give the job to someone who is capable and needs some extra cash.![]()
Once we see the complete kit, it might turn out to be easier to modify the FFR provided upper A-arm adapter.
There is even a chance that, after intial release, FFR might provide the option of an STI specific A-arm adapter.
As a side note...are folks really considering the Brembos for an 1800 pound car? Or is this mainly a 'looks'/showcar thing? I kinda see it as unnecessary weight gain.
I bought the Brembos because I got them as a package deal along with an engine and many other parts for much less than it would have cost be to buy even a non-turbo donor, so I went for it. I don't think I'll need them, so yeah, the "bling" factor will be nice, filling up the 18" wheels, but if it wasn't for the extremely cheap price, I wouldn't have got them.
Something I've been thinking about and wanted to ask, what about the Factory Five supplied axles?
Aren't the spline sizes/patterns of the WRX and STI's different? So I'm assuming the Factory Five axles won't fit into 05 STI rear hubs. If not, is it possible to modify them to fit?
for a track day cars the Brembos would be awesome... a bit of overkill for my street/autocross build. Hard to need big brakes for such low speeds...
I know the Brembos are overkill but I got a great deal on pretty much stripping a 2005 STI Spec-C so I'd like to use as much as I can that I already have. Even if some modifications/machining is required, I think it will be worth it. Another thing is I *really* want to be able to use 5x114 without adapters since the selection of wheels and offsets is MUCH better.
Mine will see probably three track days a year, so they won't be getting fully utilized all the time, but when I need them, they'll be nice to have. When I don't need them, they'll still be nice to look at![]()