STI Suspension Swap Project

Crazy_pilot · #1 11-12-2007, 09:05 PM

I posted this in the Megan Racing group buy thread, but thought I'd start a new thread to get more opinions. I'm planning on test fitting a v7 STi suspension in my SVX in the coming weeks. I've already found a way around the front sway bar endlink of the SVX. The rear endlink from an '05 Outback is the perfect length to fit a bracket welded to the control arm:

This removes the requirement to have the endlink attach to the strut. For the test phase I would just fabricate a bracket myself, but if this works I'll go to the machine shop and have a batch cut properly.

A member of the local Subie club has offered to let me borrow a spare v7 suspension he has since upgrading to coilovers. All I need it for is a mock up and fit test. He's confirmed that it uses the two bolt lower strut-to-knuckle mount in the rear (some Subies have a pillowball bushing in the rear).

To the best of my knowledge, if the lower strut will attach to the knuckle, this should work. If the top hat won't fit is it possible to swap the SVX top hat from a Koni/GC system onto another coilover system? If that's possible the only fitment requirement is the lower mount.

Is there any reason that the STi shocks won't work with the SVX's additional weight? I'm not worried about a two-year life expectancy or something, more a "will-this-thing-blow-up-if-I-hit-it-too-hard" sort of thing.

If this works I would like to go straight to an aftermarket STi suspension, coilovers etc. The heavy spring rates should help negate the extra weight, right?

I'm a rookie at all of this, so any of you more knowledgable types feel free to tell me I'm out to lunch.

It's Just Eric · #2 11-12-2007, 11:22 PM

talk to benebob.

Hocrest · #3 11-13-2007, 05:26 AM

You will need to use the SVX top mounts, or drill out different holes on the body of your SVX. If you decide to use the SVX top mount, you will find the top of the strut rod is slightly different. We used a small metal collar.

For the bottoms of the strut where they mount to the spindle. The spindle is thicker on an SVX than it is on the Impreza's. You will either need to spread open the flange on the borrowed STI struts or do what we did on the racer and use a grinder and remove metal from both sides of the spindle.

Looking at your picture posted, are you sure that there is enough clearance between the sway bar and the axle when the suspension drops? From that angle it looks fairly tight?????

Crazy_pilot · #4 11-13-2007, 05:06 PM

Quote:

Originally Posted by Hocrest

Looking at your picture posted, are you sure that there is enough clearance between the sway bar and the axle when the suspension drops? From that angle it looks fairly tight?????

Cool, thanks!

That's the normal position of the swaybar. The other end is still connected to the strut with the stock SVX link.

Hocrest · #5 11-13-2007, 05:13 PM

Quote:

Originally Posted by Crazy_pilot

Cool, thanks!

That's the normal position of the swaybar. The other end is still connected to the strut with the stock SVX link.

Ok, but in the normal set up, the sway bar is attached to the strut and won't be dropping any lower, the axle in relation will be dropping away from it.

With your set up, the control arm will be pulling the sway bar down as it does with the axle.

I'm not saying that there will be a problem, just double check before you weld things into place.

Crazy_pilot · #6 11-13-2007, 05:37 PM

The sway bar is connected to the lower strut housing, which does move up and down. The bracket I would put would make the sway bar follow the movement of the control arm at that point, and the control arm and axle should remain roughly parallel as the suspension travels, so the sway bar should not come any closer or farther from the axle than it is right there. That's what my metal picture of the situation tells me anyway.

Once the bracket's on and the strut is out I'll move the knuckle as far up and down as it will go to confirm clearance.

Crazy_pilot · #7 11-18-2007, 12:18 PM

Yay free stuff!!

Some V7 STi takeoff struts from Japan. Brand freakin new too, only about 5000 miles on them.

Time to start measuring.

sicksubie · #8 11-18-2007, 03:15 PM

well????????

Crazy_pilot · #9 11-18-2007, 03:15 PM

Well I've hit a roadblock. The raised part of the STi front upper strut mount is too large to fit through the hole in the SVX. Th hole is about 3.75", and the raised part of the mount varries from 3.8-4.1". Also, the studs on the mount are more widely spaced on the STI, and need as much as 0.5" more space, which I'm not sure the SVX has to spare. All this points to needing to use the upper mount for the SVX in the front.

I've also been doing some thinking about swapping the whole STI knuckle and hub into the SVX. They have different ball joints, but an adapter can be made to overcome that. The biggest problem I see is that with the STI knuckle, we will HAVE to run the Brembos. Nothing wrong with that, it's just a bunch more money, on the brakes and the rims to fit over them.

The reason for that is that when Tom tried to fit the Brembos he found that the SVX, while having the same bolt pattern, has the caliper mounted farther out from the center of the hub. This means that to run Brembos on an SVX, you need larger rotors than an STI would, and the calipers really can't work properly with larger rotors. Mounting an SVX caliper on an STI knuckle would bring it closer to the center, and would not allow us to use our stock rotors. So unless there's a good substitute in the size that would require, it would be Brembos or nothing. (The Subaru 4-pots might fit, but I don't know if there's a 5x114.3 rotor that will work with those)

Crazy_pilot · #10 11-18-2007, 03:15 PM

lol, nice timing

Seraphinwolf · #11 11-18-2007, 05:39 PM

Quote:

Originally Posted by Crazy_pilot

lol, nice timing

I take it that was in responce to something from SickSubi about just selling some Brembros?! LOL I would bet it is. See you should have sold them to me instead, Sickboy! LOL! To be honest I do feel sorry that you had that option slip through your fingers. Would have been nice to stop the Supercharger in less than 200ft. LOL Wow that's a lot of "L.O.L."s sorry, got carried away Let me know how it goes though I'd like to do something about my suspention and would like to know my plan like 6 months ahead of time.
-Gaddis

Crazy_pilot · #12 11-18-2007, 06:32 PM

Quote:

Originally Posted by Seraphinwolf

I take it that was in responce to something from SickSubi about just selling some Brembros?! LOL I would bet it is. See you should have sold them to me instead, Sickboy! LOL! To be honest I do feel sorry that you had that option slip through your fingers. Would have been nice to stop the Supercharger in less than 200ft. LOL Wow that's a lot of "L.O.L."s sorry, got carried away Let me know how it goes though I'd like to do something about my suspention and would like to know my plan like 6 months ahead of time.
-Gaddis

Actually it was in response to Sicksubie saying "Well??????" at the same minute I posted a long ass blurb starting with Well

sicksubie · #13 11-18-2007, 07:39 PM

Quote:

Originally Posted by Seraphinwolf

I take it that was in responce to something from SickSubi about just selling some Brembros?! LOL I would bet it is. See you should have sold them to me instead, Sickboy! LOL! To be honest I do feel sorry that you had that option slip through your fingers. Would have been nice to stop the Supercharger in less than 200ft. LOL Wow that's a lot of "L.O.L."s sorry, got carried away Let me know how it goes though I'd like to do something about my suspention and would like to know my plan like 6 months ahead of time.
-Gaddis

Nope.... I didn't let the brembos "slip through my fingers" I sold them so as to do my entire 6 spd swap for less than 1800.-.

(gloating)

Seraphinwolf · #14 11-20-2007, 07:09 PM

Quote:

Originally Posted by sicksubie

Nope.... I didn't let the brembos "slip through my fingers" I sold them so as to do my entire 6 spd swap for less than 1800.-.

(gloating)

But at the cost of selling the Brembo for way less than what they are worth and thus FAILING! You could have done you're 6-speed for around $800 instead. Or have atleast posted up on here for offers. I could have come up with the money. I know my Impreza would be cool with it(though I'd have to then convert again now that I did 02' Rex brakes in the rear) I supose it's okay. I would like to see getting a set of Impreza Coilovers under these cars (heavier duty ones) Makes it easier to find stuff.
-Gaddis

redlinedeath · #15 11-28-2007, 11:06 PM

Quote:

Originally Posted by Crazy_pilot

I've also been doing some thinking about swapping the whole STI knuckle and hub into the SVX. They have different ball joints, but an adapter can be made to overcome that. The biggest problem I see is that with the STI knuckle, we will HAVE to run the Brembos. Nothing wrong with that, it's just a bunch more money, on the brakes and the rims to fit over them.

The reason for that is that when Tom tried to fit the Brembos he found that the SVX, while having the same bolt pattern, has the caliper mounted farther out from the center of the hub. This means that to run Brembos on an SVX, you need larger rotors than an STI would, and the calipers really can't work properly with larger rotors. Mounting an SVX caliper on an STI knuckle would bring it closer to the center, and would not allow us to use our stock rotors. So unless there's a good substitute in the size that would require, it would be Brembos or nothing. (The Subaru 4-pots might fit, but I don't know if there's a 5x114.3 rotor that will work with those)

im not incredibly familiar with suspension setups, so im sorry if what i say is just stupid

anyhow, with these problems(not including top mount issues) you cant just swap out the whole suspension/knuckle/hub/brake system and new rims (off a stock sti maybe) and make it work? im sure that was just stupid, as i dont know suspension systems well, but is this not possible? i apologize in advance if it was that bad of a question