What would need to be done to modify STI spindles to work with the 818?

[nkw8181]

I have heard they are different and do not work but what are the differences. I know the rear has a different spline count and is larger. What about the front other then it won't fit? Is it the same geometry only wider and could be trimmed down? is the rear the same geometry? I'm trying to figure out what I would need to do to use the sti spindle and hubs.

Thoughts??

Nolan

[michael everson]

I am attempting to use them as well. So far the only issue is the spline count and diameter of the rear spindles. I plan on having custom CVs made. I am not far enough along to say for sue that they will work.
Mike

[Mechie3]

The 5x114.3 spindles (05+ STI) have a thicker body where it bolts to the strut.

[longislandwrx]

This has been brought up a few times. for the fronts, normally you would need to machine them thinner, weld and redrill one of the holes. This service is available from a couple companies.

With the FFR provided bolt on bracket, there may be enough flex that it will fit, and you may just be able to redrill the bracket. I would work with FFR about making a new bracket, or do it yourself (not much to it)

Capture.JPG

The rear is the same size physically but you will need modified cvs to make the sti hub work with the front wrx inner cvs and ffr provided axles. I am optimistic but I think rear outer cvs from an SVX might do the trick.

[michael everson]

My fronts were from an 04 STI and bolted right up to FFRs bracket.
Mike

[Mechie3]

04 STI is 5x100, not 5x114.3.

[nkw8181]

The donor I'm looking at will need a new front left regardless. Once I'm sure I'm getting this donor I'll start looking for sti front parts. Now what is this about SVX? I should mention that I'm new to Subaru but I'm not afraid to try things.

Nolan

[Turboguy]

My fronts were from an 04 STI and bolted right up to FFRs bracket.
Mike

Apparently, the '04 STi was a "one off" year for a lot of things, Mike. Bolt pattern changed for the '05 onward STi's.

[Mechie3]

Now what is this about SVX? I should mention that I'm new to Subaru but I'm not afraid to try things.

Nolan

Not sure if you're asking what the SVX is, or what's special about it. The SVX was a one off car for many things. A lot of parts are swappable between all imprezas from 93 or so on up to STI's in 2007 and swappable between impreza and legacy. The SVX had a lot of unique parts including 5x114.3 bolt patterns, but not the R180 diff if I recall correctly and would be the only factory Subaru like this.

Long island is thinking that you could adapt FFR's axles with an SVX outer CV to make an axle assy that can fit the STI hubs without needing custom pieces. The only problem with SVX's are the scarcity.

[longislandwrx]

Testify Mechie3! , If you are asking what is special, the SVX, aka God's own chariot used the larger STi sized hubs but the WRX's R160 rear diff so my guess is the axle splines match the WRXs. Fun part will be finding an SVX with oem axles. It's doable though, I know a yard in Portland, OR that has at least 12 SVXs.

care to be the space monkey?

If you are asking what an SVX is...

svx6.jpg

[Xusia]

^ Oh gawd. What did they DO to it??

[Frank818]

Oh come on... how "not" driveable that SVX is. lolll

[nkw8181]

My eyes my eyes! Lol thanks for all the good info. I'm going to look into the svx hubs and if not worst case I could have shafts made. From what I've found it looks like the outer for an sti is a 27 spline while wrx is a 25. If this is accurate I just need to find out if the svx has the 25 with a bearing that fits an sti. With that being said I may only need the internals for the svx 's cv

[sponaugle]

I am in the same boat as the OP. I have a 2006 STI I am using as the donor car, and I want to use the 5x114.5 STI hubs.

As mentioned above the fronts will require either some shaving and drilling, or making a new bracket.

For the rear you normally use a stock WRX rear outer CV and a stock WRX inner front CV with the FFR provided axles. Based on what was said above the rear STI hubs have a larger spline (on the hub side), so you can't use a WRX rear outer CV. I assume that if you used the STI rear outer CV that the provided FFR axle will not work?

A solution might be to just get custom axles made. Given the length of the FFR ones it wouldn't be hard to spec one that will fit into the WRX inner front CV and the STI outer front CV. Actually for that matter I'm not sure why you couldn't use the STI front inner CV if you are getting a custom axle made.

Does this sound reasonable? Anyone else interested in axels like this?

*EDIT* A second option would be to purchase new/use 2004 STI spindles and hubs, as the 06 STI Brembos would bolt up to them. A complete new set of front and rear knuckles+hubs+bearings is about $1600. Of course this assumes the rear 04 STI hubs are the smaller spindle... hmmm..


Jeff

[icky]

*EDIT* A second option would be to purchase new/use 2004 STI spindles and hubs, as the 06 STI Brembos would bolt up to them. A complete new set of front and rear knuckles+hubs+bearings is about $1600. Of course this assumes the rear 04 STI hubs are the smaller spindle... hmmm..


Jeff

you are still left to figure out the rear spindles, I believe DSS makes FFR's axles but either way they have the tooling to make the axles you need. STI front inner and STI rear outer splined axle-shafts.

[longislandwrx]

*EDIT* A second option would be to purchase new/use 2004 STI spindles and hubs, as the 06 STI Brembos would bolt up to them. A complete new set of front and rear knuckles+hubs+bearings is about $1600. Of course this assumes the rear 04 STI hubs are the smaller spindle... hmmm..
Jeff

That's a lot of money and trouble to go to to still end up with 5x100s... For the front, to mill the 06 STI knuckles just a little thinner shouldn't be more than $100 at a machine shop, then just drill yourself a new hole for a new m14bolt. I think welding up the old hole is unnecessary.

For the rears (using the 5mt) I would still like to see someone find a set of svx axles to see if the outers will work with the FFR provided axles. If using a 6 speed, FFR may already have an axle for the 6mt (since they are using it on the R) that axle in conjunction with the svx outer may be your answer.

[sponaugle]

you are still left to figure out the rear spindles, I believe DSS makes FFR's axles but either way they have the tooling to make the axles you need. STI front inner and STI rear outer splined axle-shafts.

Yes.. that is true. I could have DSS make a custom axle set that will attach to the front WRX inner CV and the rear 06 STI outer CV. With that combination I could use either a 5 speed or a 6 speed, as the front WRX inner CV is female and you can install the shafts into a 6 speed to make it fit.

All of this depends on the notion that infact the diameter and spline count on the inside joint of the rear outer CV is different between the WRX and the STI. While I think this is true, it would be good to confirm.

Jeff

[sponaugle]

That's a lot of money and trouble to go to to still end up with 5x100s... For the front, to mill the 06 STI knuckles just a little thinner shouldn't be more than $100 at a machine shop, then just drill yourself a new hole for a new m14bolt. I think welding up the old hole is unnecessary.
For the rears (using the 5mt) I would still like to see someone find a set of svx axles to see if the outers will work with the FFR provided axles. If using a 6 speed, FFR may already have an axle for the 6mt (since they are using it on the R) that axle in conjunction with the svx outer may be your answer.

Agreed on the cost, as that is a lot of money to spend to get new hubs when I have a perfectly good set here... also using the 5x114.5 has the benefit of easy to swap bearing assemblies.

As for the SVX outers, it would be interesting to try. It is hard to find spline count/size for the interior CV joints (the CV to shaft junction, not the CV to hub or CV to transmission).

It should not be required to get a different axle from FFR if you plan to use a 6-speed. If you have the female WRX front inner CV, and you want to attach to a post 04 6 speed that is also female, you can just purchase the stubs, seals, and end caps. In other words you can convert a >04 6 speed to look just like a 5-speed with stubs sticking out.

Jeff

[ssssly]

DSS makes 100 to 114 axles for the WRX. If the axles are indeed sourced from DSS, this really should be an option at purchase.

[longislandwrx]

It should not be required to get a different axle from FFR if you plan to use a 6-speed. If you have the female WRX front inner CV, and you want to attach to a post 04 6 speed that is also female, you can just purchase the stubs, seals, and end caps. In other words you can convert a >04 6 speed to look just like a 5-speed with stubs sticking out.
Jeff

Will the male 05+ inners plug right into the STi? I was under the impression they were different... that's good news.

[Wayne Presley]

The male part of the inner CV is the same on the 5 speed and 6 speed transmissions. When FFR installed the 6 in the 818R, they used the same half shafts that were in the car for the 5 speed. 2006 WRX 5x100 rear knuckles.

[sponaugle]

Will the male 05+ inners plug right into the STi? I was under the impression they were different... that's good news.

The male part of the inner CV is the same on the 5 speed and 6 speed transmissions. When FFR installed the 6 in the 818R, they used the same half shafts that were in the car for the 5 speed. 2006 WRX 5x100 rear knuckles.

As Wayne said, the 5-speed and 6-speeds outputs are compatible (with the exception that if you have a post 04 6-speed with female connections you will need the small stubs, seals, and end caps.). This is why you can drop a 6-speed in a wrx and the front axels and hubs don't have to change.

My problem is of course that I am using 06 STI hubs, which do have a different axel shaft size. While DSS does make 100-114 axles for Subarus, they don't by default make one of the correct length for the 818... however they can do that easily.

Once I get my kit, I'll order up the axles and confirm everything works.

The real question now is what to do about the front. I could either modify the 'adapter' provided by FFR, or have my own bracket made that is thicker to accommodate the STI hubs.

Jeff

[longislandwrx]

I guess if you're racing I would modify the part less likely to be damaged... I think its easier to mill the knuckle, but then you might have a tough time finding a replacement if you bend one... having an extra bracket on hand (since they are symmetrical) might be the smarter choice.

Have you tried to fit the bracket as is? There may be enough flex where it wont matter. See my post #4... there's some room to play with.

[ssssly]

The real question now is what to do about the front. I could either modify the 'adapter' provided by FFR, or have my own bracket made that is thicker to accommodate the STI hubs.

Jeff

Just ordered my kit so I haven't had a chance to look at the actual parts yet. But from my experience building Subarus and the description here my take is the following.

The primary benefit of the 114 hubs is the easy bearing swap out the slight strength increase, plus the ability to use the Brembos. Since the car is rear wheel drive and the biggest Brembo hurdle is the parking break in the rear hubs, you are getting 99% of the benefit by just using the rear 114 hubs.

So why not go drifter style? Use the 114 hubs in the rear with the custom axles for the strength where you need it and 100 in the front for ease of install where you don't really need the extra strength. You can easily get 114 brembos on a 100 hub and there are plenty of wheel options that come in both 100 and 114.

Obviously not the only solution, but after reading this thread, the one I am leaning toward. Of course unless they come out with front brackets that will fit the 114 hubs.

[metalmaker12]

The 2004 Sti and almost all jdm Sti are 5x100 and use brembos

[ssssly]

From 2001 to 2004 JDM STIs were 5x100 with Brembos. Like the USDM 04 STI. The fronts are interchangeable with minor tweaks. The rears are not. The 5x114 rear rotor and hub assembly is a totally different size and the parking break assembly will not work from one to the other.

Was working on the assumption the OP had a full 114 hub setup with 114 Brembos. Which would require very minor modifications to work on the front 100 setup.

LIC motorsports also makes custom knuckles so you can mount the 5x114 bearing assembly into a 5x100 knuckle. Is kind of spendy though.

http://www.licmotorsports.com/produc...i_lic-03079012

[Xusia]

Given how much trouble the 5x114 hubs seem to be, they really don't seem worth the effort to me. But each his own!

[ssssly]

The 2004 Sti and almost all jdm Sti are 5x100 and use brembos

Only the 01-03 JDM STIs have 5x100 Brembos. Every 04+ JDM STI is 5x114. 92-01 use Nissan 4pot, 2pot setups. Very few STIs, USDM or JDM, are 5x100.

[ssssly]

After a few emails back and forth with DSS, seems the 5x100-5x114.3 shafts for an 818 can be had for $199 a piece for those interested.

[nkw8181]

If i'm not mistaken (and I could be) i thought the hubs where slightly different I.E. the bottom is rotated back or something??

[icky]

You are mistaken, the control arms made the caster change, even the part #'s are the same. The rears should just take custom axles that ffr does not yet supply ( idk why!), and the fronts should take either milling and one hole re-drilled ( on the knuckle) or after seeing the FFR upper control arm there is a metal spacer welded in that if removed, just might fit. Another one of those if they don't they should be so that people can use the sti as a donor.

[nkw8181]

Ok cool! to much data input into the old brain and it can get all jumbled up

[Santiago]

... the fronts ...after seeing the FFR upper control arm there is a metal spacer welded in that if removed, just might fit. Another one of those if they don't they should be so that people can use the sti as a donor.

Icky, I thought I had seen this too, but then couldn't find the pic. The one longisland posted doesn't seem to show this welded-in spacer on the knuckle adapter, but I swear I've seen some pics that really look like there's a spacer that's just tacked in. I wonder if this is a part revision on FFR's part? Anyone have a clear picture of their knuckle adapter with spacer?

At any rate, I agree that this just seems like an easy fix on FFR's end (at least for the front).

Best,
-j

[Wayne Presley]

like this? There are plates welded to the inside of the bracket, almost like FFR allowed for the STI spindles down the road....

[Kurk818]

Im using an 06 STI as a donor and did just what has been suggested. I removed the plates and re-welded them to the outside.. I had to cut the spacer in half to accommodate the larger spacing between the bolts as well. It worked out great. The rear did not create any issues for installation.

Im also going to be using the 6 speed and don't foresee any issues with the fitment.

[longislandwrx]

That's pretty cool, but I am 100% sure mine are flat like the first picture

[Bob_n_Cincy]

Mine, chassis #21 & 22 had the plates on the inside of the with a couple of weld drops. 2 min on a grinder taking off the welds and the plates would be off. I'm not sure they made them that wide for the STI. They made them that wide so a socket will fit on the top ball joint nut.
You can see 3 weld spots on the picture below

welds.jpg
Bob

[Santiago]

That's very good to see. Thanks fellas!

I'm looking forward to how things go with your 6-speed install Kurk. Seems like the sort of thing that FFR could support with little trouble, but they haven't yet, so that makes me a little puzzled at what the challenge is on their end. Anyway, as Michael says, "We'll get there pop."

-j

[icky]

Yeah, so it looks like the sti will be a complete donor soon!