sway bars....?

[markv]

I've been doing a lot of research on sway bars. and i can't seem to find out the right fit(bar size wise)

a lot of ppeople are saying to just get a sway bar and strut bar for the rear alone.....but i think that will dramatically change the cars handling, possibly increase the oversteer a little too much....

can i get some help with this?

[StatGSR]

^ typicly upgrading a rear sway bar is going to increase oversteer, not understeer.

[Kraziken]

A lot of people recommend not upgrading the front swaybar. But the swaybar also controls body roll.

Take a look at this conversion chart.

http://www.whiteline.com.au/docs/bulletins/010barup.pdf

As you can see, if you go from a 20mm front swaybar (stock size) to a 22mm swaybar, that is a 46% increase in stiffness.
If you go from a rear 16mm to 18mm, that is a 60% increase in stiffness.
If you go from 16mm, to 20mm in the rear, that is a 144% increase in stiffness.

I recommend upgrading both front and rear swaybars. If done properly, you can keep the same general balance in your car and overall reduce body roll with out greatly inducing oversteer or understeer in your car.

[Huffer]

I've been doing a lot of research on sway bars. and i can't seem to find out the right fit(bar size wise)

a lot of ppeople are saying to just get a sway bar and strut bar for the rear alone.....but i think that will dramatically change the cars handling, possibly increase the understeer a little too much....

can i get some help with this?

First question - why do you want to upgrade your swaybars?

[Wiscon_Mark]

Keep in mind, with less body roll, you'll be more inclinded to go faster through corners, and more will fall on your tires, so if you plan to upgrade swaybars, get appropriate tires, and drive accordingly.

A rear bar will increase oversteer, not understeer.

[Kraziken]

Keep in mind, with less body roll, you'll be more inclinded to go faster through corners, and more will fall on your tires, so if you plan to upgrade swaybars, get appropriate tires, and drive accordingly.

A rear bar will increase oversteer, not understeer.

Although if you have crappy tires, it might be a good reason to burn them completely off before buying new ones. :grin:

[rougeben83]

The one caveat to a swaybar is you'll loose a little bit of independence between right and left tire. That means if you encounter a bump or uneven patch of road mid corner the suspension may react like a solid beam suspension and you'll end up skittering.

On a Macpherson strut front suspension like our cars, a bigger front sway will actually reduce understeer as well ; the bigger bar will keep severe changes in camber due to hard cornering in check and will maintain the contact patch on the ground. End result is your front won't loose grip as quickly, which is understeer.

So don't go too big with whatever bar you choose, but start off with the rear as that is usually what is really undersized from the factory.

[Wiscon_Mark]

Interesting info on the front bar, Ben. I'd heard that before, but you put it in terms that make sense.

I shall be getting a front bar sometime soon :grin:

[markv]

The one caveat to a swaybar is you'll loose a little bit of independence between right and left tire. That means if you encounter a bump or uneven patch of road mid corner the suspension may react like a solid beam suspension and you'll end up skittering.

Thats what i am kinda worried about. Because when i head down to school every morning I got some of those pot holes that when its the right amount of traffic, you cannot really avoid them. And I dont exactly wanna go over them at a descent speed and lose control or anything

And the reason Im thinking about upgrading is because there are a lot of back roads around the area that i live in, and yes I like to take some of the turns a little quick. But its something to occupy me before and after work. But also because I hate the feeling of my car leening to much to one side. Say what you'de like, but I also think its gonna help in the long run.

[Huffer]

What's the size of the stock sways on your Legacy right now?
20/22 (front/rear)?

[Wiscon_Mark]

MarkV- you won't hit a pothole and lose control because of a swaybar. It just makes you feel the bumps a little more in the ass end of the car.

The positives strongly outweigh the negatives if you have a good set of rubber.

[Kraziken]

The one caveat to a swaybar is you'll loose a little bit of independence between right and left tire. That means if you encounter a bump or uneven patch of road mid corner the suspension may react like a solid beam suspension and you'll end up skittering.

On a Macpherson strut front suspension like our cars, a bigger front sway will actually reduce understeer as well ; the bigger bar will keep severe changes in camber due to hard cornering in check and will maintain the contact patch on the ground. End result is your front won't loose grip as quickly, which is understeer.

So don't go too big with whatever bar you choose, but start off with the rear as that is usually what is really undersized from the factory.

Interesting, where did you read it would reduce understeer?

I will provide my Buttdyno results. When I ordered my swaybars, it just happened that PDM racing didn't account for 99 Legacy's were actually BE/BH cars in their catalog, so they sent me the wrong rear swaybar.

I had my front swaybar laying around. I had heard people mention not to install the front swaybar because it adds understeer to a car platform that already understeers.

Well I installed it anyway as a test. So I was running a 22mm front swaybar with the stock rear 16mm swaybar.

I then took the car up some winding roads, and pushed it about 8/10ths. The car felt great. I might have felt a little push, but the body roll was much more controlled.

So I've ran a greatly out balanced setup, yet I still felt the improvement from the front swaybar.

You have to realize the WRX folks are running 24 to 27mm front swaybars as well without issues. Going from a 20mm to a 22mm bar in the front is not a dramatic change.

[Huffer]

Going from a 20mm to a 22mm bar in the front is not a dramatic change.

I dunno, a 46% increase in stiffness plus increased turn-in sounds like a fairly dramatic change to me. ;)

[Kraziken]

Going from a 20mm to a 22mm bar in the front is not a dramatic change.

I dunno, a 46% increase in stiffness plus increased turn-in sounds like a fairly dramatic change to me. ;)

Heh, perhaps, but if you think of the rear swaybar. Going from a 16mm to a 20mm is a 144%, or 22mm is 257%. That is a big change. :grin:

I currently have my rear adjustible set to 20mm. I think I may have to try it at 22m to see the difference.

[rougeben83]

ken, check the suspension forums on NASIOC. Some STi's actually just run upgraded front swaybar...sometimes as massive as 27mm (over 1" in diameter).

The key here is that they're trying to compensate the inherent weakness of the front suspension design that a lot of Subaru's share. Keeping the front end as planted as possible increases the threshold before the front will washout. The added benefit is better turn-in because of the stiffer front end.

20/22 is fine IMO. You'll only really notice the stiffer bars on uneven road surfaces where the right side is hitting bumps at different times as the left side. The skittering would only really happen when you're running extreme combinations. I'm running 19/22 w/ upgraded endlinks and rallycross; I've hit larger bumps and holes in the dirt than any regular car would on the street and I never experienced any loss of control due to the stiffer rear bar. The only real time I could experience the stiffer rear end is when I induce it on a slick/loose surface to get the car to rotate.

[Kraziken]

ken, check the suspension forums on NASIOC. Some STi's actually just run upgraded front swaybar...sometimes as massive as 27mm (over 1" in diameter).

The key here is that they're trying to compensate the inherent weakness of the front suspension design that a lot of Subaru's share. Keeping the front end as planted as possible increases the threshold before the front will washout. The added benefit is better turn-in because of the stiffer front end.

20/22 is fine IMO. You'll only really notice the stiffer bars on uneven road surfaces where the right side is hitting bumps at different times as the left side. The skittering would only really happen when you're running extreme combinations. I'm running 19/22 w/ upgraded endlinks and rallycross; I've hit larger bumps and holes in the dirt than any regular car would on the street and I never experienced any loss of control due to the stiffer rear bar. The only real time I could experience the stiffer rear end is when I induce it on a slick/loose surface to get the car to rotate.

I was wondering, is it possible to run a WRX/STI 27mm bar on our cars?

I know it is a different platform (RWD) etc. But the Hotchkis sways I bought for my wife's car had a 30mm front sway bar.

[MCarp22]

I'll chime in that Ben is pretty much spot-on with the front bar. :)

[rougeben83]

ken, check the suspension forums on NASIOC. Some STi's actually just run upgraded front swaybar...sometimes as massive as 27mm (over 1" in diameter).

The key here is that they're trying to compensate the inherent weakness of the front suspension design that a lot of Subaru's share. Keeping the front end as planted as possible increases the threshold before the front will washout. The added benefit is better turn-in because of the stiffer front end.

20/22 is fine IMO. You'll only really notice the stiffer bars on uneven road surfaces where the right side is hitting bumps at different times as the left side. The skittering would only really happen when you're running extreme combinations. I'm running 19/22 w/ upgraded endlinks and rallycross; I've hit larger bumps and holes in the dirt than any regular car would on the street and I never experienced any loss of control due to the stiffer rear bar. The only real time I could experience the stiffer rear end is when I induce it on a slick/loose surface to get the car to rotate.

I was wondering, is it possible to run a WRX/STI 27mm bar on our cars?

I know it is a different platform (RWD) etc. But the Hotchkis sways I bought for my wife's car had a 30mm front sway bar.

Most likely not; moreso the fact that NA and turbo front xmembers are not the same. I think I remember comparing NA and turbo swaybars and the turbo ones are usually straight in the middle, while NA ones have a lot of little bends. For the rears though...I don't know. BE's can't use any suspension component from any other subaru though, so my car is out of luck :(

[subaru_terrence]

ken, check the suspension forums on NASIOC. Some STi's actually just run upgraded front swaybar...sometimes as massive as 27mm (over 1" in diameter).

The key here is that they're trying to compensate the inherent weakness of the front suspension design that a lot of Subaru's share. Keeping the front end as planted as possible increases the threshold before the front will washout. The added benefit is better turn-in because of the stiffer front end.

20/22 is fine IMO. You'll only really notice the stiffer bars on uneven road surfaces where the right side is hitting bumps at different times as the left side. The skittering would only really happen when you're running extreme combinations. I'm running 19/22 w/ upgraded endlinks and rallycross; I've hit larger bumps and holes in the dirt than any regular car would on the street and I never experienced any loss of control due to the stiffer rear bar. The only real time I could experience the stiffer rear end is when I induce it on a slick/loose surface to get the car to rotate.

I was wondering, is it possible to run a WRX/STI 27mm bar on our cars?

I know it is a different platform (RWD) etc. But the Hotchkis sways I bought for my wife's car had a 30mm front sway bar.

Most likely not; moreso the fact that NA and turbo front xmembers are not the same. I think I remember comparing NA and turbo swaybars and the turbo ones are usually straight in the middle, while NA ones have a lot of little bends. For the rears though...I don't know. BE's can't use any suspension component from any other subaru though, so my car is out of luck :(

Where can we get sways for BE then?
whiteline only?

[Kraziken]

Most likely not; moreso the fact that NA and turbo front xmembers are not the same. I think I remember comparing NA and turbo swaybars and the turbo ones are usually straight in the middle, while NA ones have a lot of little bends. For the rears though...I don't know. BE's can't use any suspension component from any other subaru though, so my car is out of luck :(

Ah, but I have a turbo front Xmember. :grin: :grin: I know I have a Perrin bar up front. I'm not sure of the part number.

It seems on Nasioc, a few WRX wagon owners have experimented. Some of them are successfully running the 27mm whiteline bar up front and a 24mm rear bar.

I'm not sure if any of the larger rear bars will fit.

To adjust for some of the angles, they are using the Whiteline spherical ball joints.

[rougeben83]

Most likely not; moreso the fact that NA and turbo front xmembers are not the same. I think I remember comparing NA and turbo swaybars and the turbo ones are usually straight in the middle, while NA ones have a lot of little bends. For the rears though...I don't know. BE's can't use any suspension component from any other subaru though, so my car is out of luck :(

Ah, but I have a turbo front Xmember. :grin: :grin: I know I have a Perrin bar up front. I'm not sure of the part number.

It seems on Nasioc, a few WRX wagon owners have experimented. Some of them are successfully running the 27mm whiteline bar up front and a 24mm rear bar.

I'm not sure if any of the larger rear bars will fit.

To adjust for some of the angles, they are using the Whiteline spherical ball joints.

Yeah the most likely scenario is one of the arms starts hitting something (just like the rear on my car hmmmm...). If you have some adjustable length endlinks, that'll do a lot to help. I have a set of Hotchkis heim-joint endlinks I'll try when I decide to get the bigger bar.

I think IPD has a 22mm one for N/A cars for around $110. Cusco and Whiteline make FSB's too, for the other guy that asked.

[lgt2000]

for the BE, I went to a local shop here last week and while we had the car on lift we tried to fit a stock rear bar from a 05 STI and we got it to almost fit, what is needed is longer endlinks by about a 1/4" and to remove the brace that goes to the bottom of the trunk

[rougeben83]

for the BE, I went to a local shop here last week and while we had the car on lift we tried to fit a stock rear bar from a 05 STI and we got it to almost fit, what is needed is longer endlinks by about a 1/4" and to remove the brace that goes to the bottom of the trunk

If any one is looking for a cheap upgrade, BH outbacks got 18mm rear swaybar, and it costs around $70 online.

[outbackmike]

what size sway bars does a 98 outback(BG) have?
front and rear,now that i got the strut bars i think the next thing will be sway bars...

[Wiscon_Mark]

what size sway bars does a 98 outback(BG) have?
front and rear,now that i got the strut bars i think the next thing will be sway bars...

18mm rear, 20mm front I believe.

A swaybar from an Outback is a common upgrade for the GT and L owners. You'd have to go aftermarket to upgrade swaybars.

[outbackmike]

thanks mark,
i wasnt planing on getting subaru parts,probably whiteline,or perrin...
i just need to choose what size to go with.

[AJM]

what size sway bars does a 98 outback(BG) have?
front and rear,now that i got the strut bars i think the next thing will be sway bars...

18mm rear, 20mm front I believe.

A swaybar from an Outback is a common upgrade for the GT and L owners. You'd have to go aftermarket to upgrade swaybars.


I measured a 96 outback once and it was 18mm front, did they change it for phase 2?

[Wiscon_Mark]

?? I was under the impression that the only two sizes for 2nd gen Legacys were 19mm and 20mm for the front. I find it hard to believe that the Outback would get a smaller front bar than the L sedan.

[Huffer]

Unless you use really accurate calipers, 18mm and 19mm are pretty easy to misjudge. Could just be operator error...

[Sharris]

Actually, if you check out the BE service manual, it notes 19mm on the 2.0L NA, 21mm on the 2.5L NA, and 20mm on the 2.0L Turbo models.

[Wiscon_Mark]

Actually, if you check out the BE service manual, it notes 19mm on the 2.0L NA, 21mm on the 2.5L NA, and 20mm on the 2.0L Turbo models.

Thanks, but our little recent discussion was on the BG :wink:

[Bimmerman]

I measured the stock front and rear swaybars on my 95 L Wagon(BK?) with really accurate calipers and got ~14.4mm rear and ~19mm front. This is with the 2.2L N/A motor.