STI Suspension Swap Project - Page 2

Crazy_pilot · #16 11-29-2007, 07:18 PM

Quote:

Originally Posted by redlinedeath

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

At this point I would say that the STI front knuckle could be used with a custom ball joint adapter. Not sure about the rear, I haven't looked at the rear knuckle to see if it's compatible with out rear suspension links. To use the STI front knuckle you would have to use the STI Brembos and a wheel the right size to fit over those brakes. To fit into the SVX strut tower you would need to either do some cutting and drilling of the SVX body, or put the SVX top mount on the strut.

Crazy_pilot · #17 11-29-2007, 07:35 PM

I did some talking with Mychailo about this idea, comparing the basic dimensions of the SVX and Impreza/STI struts. The fronts are roughly the same length, but the rear STI struts are 1.5-2" longer than ours. That in itself is not a problem, a suitable drop spring setup(or adjustable coilovers

) would bring the ride height back to normal. The problem is that the STI has as much travel as we do in the rear. So to drop the rear to normal ride height you would use up 1.5" of suspension travel, giving you less than the SVX has. So, my opinion on the swap as of now:

The STI suspension CAN be used, with modifications.

1. Both front and rear SVX knuckles will have to be thinned somehow to fit into the strut mounting flange. Either by machining or grinding. Or you can pry the flange open to fit onto the SVX knuckle.

2. SVX top mounts will have to be used, or the shock towers in the SVX body will have to be drilled and cut to accomodate the different bolt patterns.

3. A bracket will have to be welded to the front control arms, allowing an aftermarket swaybar endlink to attach to the control arm rather than the strut. A rear '05 Outback endlink works perfectly.

4. The rear STI suspension will have to be compressed. This will sacrifice roughly 1.5" of rear suspension travel. To prevent the shocks from bottoming out a higher spring rate will have to be used. This will obviously have an effect on the handling characteristics.

Cost for this way of doing it: STI suspension+machining cost for knuckles+SVX top mounts+2005 Outback endlinks+bracket+welding bracket to control arm.

The big ticket option: Use a custom machined balljoint adapter to use the STI front knuckle. This allows you to use STI Brembos, and any other BBK for the STI.

Cost for this option: All of option A (minus machining knuckle) + balljoint adapter+STI knuckle and associated parts+Brembos

Crazy_pilot · #18 09-24-2010, 12:56 PM

So.... I bought a set of Stance GR+ coilovers today. They are 2002-07 WRX fitment. It'll be a little bit before they're shipped up, but I'm excited! Every day I see my classmates' 240SX and Prelude, both of which are lowered, and I'm getting real tired of the high front end of the SVX.

Crazy_pilot · #19 10-01-2010, 08:14 AM

*manic laughter*

Gots me some stuff!!!!

Ricter · #20 10-01-2010, 08:31 AM

Get those things installed now!!

And document everything you have to do to make them work (assuming it's changed from your speculations and measurements prior).

Crazy_pilot · #21 10-01-2010, 08:53 AM

I most certainly will.

Johnybeas · #22 10-03-2010, 02:51 PM

pictures of adapted front end??? plans for the adapter???

Nevin · #23 10-10-2010, 04:07 PM

Why don't you just cut out the SVX body mount where the struts bolt to the body, and weld in your own piece that is the same fitment as the wrx top mount?

Crazy_pilot · #24 10-10-2010, 04:29 PM

Quote:

Originally Posted by Nevin

Why don't you just cut out the SVX body mount where the struts bolt to the body, and weld in your own piece that is the same fitment as the wrx top mount?

Way too much work, if my measurements are correct all I will have to do is drill two new holes in the SVX to accept the different top mount bolt pattern and grind down the part of the knuckle the strut attaches to by ~1.5mm. At the end of the day I'll still be able to go back to stock suspension with a small shim for the knuckle.

Nothing installed yet, I've got to find some free time from school to get this done.

sowise · #25 10-10-2010, 05:42 PM

Quote:

Originally Posted by Crazy_pilot

Way too much work, if my measurements are correct all I will have to do is drill two new holes in the SVX to accept the different top mount bolt pattern and grind down the part of the knuckle the strut attaches to by ~1.5mm. At the end of the day I'll still be able to go back to stock suspension with a small shim for the knuckle.

Nothing installed yet, I've got to find some free time from school to get this done.

I agree way to much work but also why drill the holes in the SVX? I have been looking at doing a similar set up and rather than put holes in the car just press the mounting studs out of the mount, mark your hole pattern for the SVX on the top mount plate, redrill the mount plate and press in the studs. That way the only thing you modified was the suspension.

Crazy_pilot · #26 10-10-2010, 07:27 PM

Quote:

Originally Posted by sowise

I agree way to much work but also why drill the holes in the SVX? I have been looking at doing a similar set up and rather than put holes in the car just press the mounting studs out of the mount, mark your hole pattern for the SVX on the top mount plate, redrill the mount plate and press in the studs. That way the only thing you modified was the suspension.

Eh, still more work. Besides, I have very little intention of going back to stock once I have these installed. If anything I'll be going from one WRX suspension system to another and I'd rather be able to just bolt the new system in. Also, the studs holes are all counterbored into the plate, so I would have to disassemble the pillowball to get at the back of it. Two small holes in the shock towers are a small price to pay.

sicksubie · #27 10-13-2010, 01:24 PM

Maybe a dumb question but why not swap SVX camber plates onto the coilovers?

Crazy_pilot · #28 10-13-2010, 01:29 PM

It's an option (as long as they bolt up), but it's just more money.

To give you an idea of just how minor the hole drilling will be:

sicksubie · #29 10-13-2010, 03:04 PM

I would be concerned with how close those holes are to each other...

StatGSR · #30 10-13-2010, 03:17 PM

^ what he said, honestly, if possible, i would re-drill all 3 holes to space them away from the existing as much as possible.