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Sway bar from Outback ???

Posted: Fri Sep 17, 2004 5:57 pm
by professor
OK no one answered my question about the size of the later Legacy rear bar, so I checked it out. the Legacy wagon is 16mm for virtually all models, but the Outback rear bar is 18mm. Obviously the outback has "revised" suspension to accomodate higher ride height, but the easiest way to do that would be to drop the spindle height and leave the control arms, sway bar, etc where it is on regular Legacies.

Is this so ??? If so the the 18mm Outback bar should fit my wagon. I'm planning to weld on brackets onto the control arms in situ, and make my own adjustable endlings so none of that matters.

Can anyone add any sage advice or am I on my own ? There should be many more Outback bars available, and fresher, than old Turbo and air suspension bars.

Posted: Mon Sep 20, 2004 5:12 pm
by professor
OK I have an '99 Outback bar on the way, and parts to make endlinks. If someone knows a reason why, please stop me from wasting $75.

If it works, I'll post pics etc. later

Posted: Mon Sep 20, 2004 9:13 pm
by BAC5.2
Wouldn't an Impreza Wagon bar be a better idea? That SHOULD bolt right up, as our suspensions are nearly identical to theirs.

An aftermarket bar isn't THAT expensive, might be a bit more than 75 bucks, but it would be of better quality than a stock bar.

I'm still curious, since I know you'll see this, as to why CUTTING the springs increases spring rate? When you cut them, you lose coils to lose height. Wouldn't the spring rate only increase if you heated and compressed the springs (keeping the same number of coils over a shorter distance)? The spring rate would remain the same if you cut them, right? I fail to see the logic in why cutting the spring raises the spring rate.

Posted: Mon Sep 20, 2004 9:39 pm
by boostjunkie
The spring rate of a spring is determined by two things:
1. The thickness of the coils
2. The number of coils and the diameter of the coiling (looking at the top of a spring)

For a better visualization, imagine a spring as a large torsion bar, just "coiled up." If you take two torsion bars of the same size diameters but different lengths, which one would take more effort to bend (if the tried to bend both from the ends)?

The answer would be the shorter of the bars.

Now take that same set of straight bars and form them into coils. Which one do you think would be harder to compress?
Which one would have the lesser amount of coils (given the same diameter and spacing between coils)?

*hint* the same shorter bar *hint*

Does that make more sense?

Your method of heating and compressing the spring would only serve to lower the car (as the same spring rate would still apply).

Posted: Mon Sep 20, 2004 10:07 pm
by BAC5.2
AHH, perfect. Thanks Jason.

Hmm.. I wonder why I never looked at it like that?

I think I was basing it on how the rear of your Legacy seemed to feel. It felt overdamped, but I guess that is because of the significantly different Tein fronts.

Posted: Mon Sep 20, 2004 10:20 pm
by boostjunkie
Glad I could help.

As for the rears being overdamped, I have no idea why it had that impression. Perhaps the STi front strut top mounts vs. the rear stockers? Also, depending on the rear spring rate, cutting off one of the coils may have made the rear spring rate stiffer, but not that much stiffer.

Posted: Mon Sep 20, 2004 10:21 pm
by Legacy777
Jason.....love the sig :lol:

Posted: Mon Sep 20, 2004 10:23 pm
by boostjunkie
Hehe, thanks Josh! :twisted:

Posted: Mon Sep 20, 2004 10:25 pm
by BAC5.2
The tops might be a reason as well. Just a lot less play up front, might have given me the impression of the rears being overdamped. Stock, we have the same spring rate front and rear, so the rear rate might have just been softer than the fronts. I didn't think about all the variables of your car, that caused that.

Posted: Tue Sep 21, 2004 2:53 am
by scottzg
impreza rear swaybars dont fit.

Posted: Tue Sep 21, 2004 3:41 am
by professor
the impreza bars are also Small. The Outback bar is attractive because it is 18mm, which should be just about right, and I'm getting the mounts and links for that price as well, all very low mileage, and shipping included, and I don't have to pick it wallowing in the muddiest week of the year.

Posted: Tue Sep 21, 2004 3:58 am
by Legacy777
you can look for a first gen leg wagon that has air suspension. Their bars are 18mm.

Posted: Tue Sep 21, 2004 4:22 am
by scottzg
Thats where i got my 18mm bar, but they're super rare an stuff.

Posted: Tue Mar 21, 2006 12:36 am
by ttmuench
So Professor did the rear 18mm outback bar work? I've got my eye on one in the local pick and pull. For that matter will the 20mm outback front bar fit on a 94 BJ?

Posted: Tue Jun 17, 2008 6:21 pm
by ttmuench
So I pulled the outback rear sway bar. It was a 95 or newer outback. I'm not sure the exact year. It fits my 94 legacy L wagon. It does rub the exhaust axel back section. Perhaps, longer rubber hangers would prevent this from occurring.