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Reason
01-31-2007, 12:31 AM
Looking at the link OutbackGT gave me, made me think. When upgrading sway bars front and rears. Should they match in size? I would like to have adjustable, but if not I want 22mm. I know on the GT the front is larger than the rear. What are the effects on having mismatched or same size bars? Can anyone give me real life experience?

MXS
01-31-2007, 12:49 AM
having a larger rear bar is like having stiffer springs in the back. it will make the car rotate better... less understeer. depends on how balanced you want the car to be.

Reason
01-31-2007, 01:11 AM
I'm looking for tight,accurate handling and steering.

Huffer
01-31-2007, 09:43 AM
Then similar sizes with maybe a TINY bias towards the rear will help.
Something like a 20/22 setup (front/rear).
Replacing worn bushings etc and droplinks is a good move too.

Rear strut braces, engine mounts and pitch stop also.

MCarp22
01-31-2007, 12:09 PM
I'm looking for tight,accurate handling and steering.

That's the front swaybar. With a big front bar, even if you remove the rear, it will feel tight and accurate.

95legacy
01-31-2007, 03:50 PM
Agreed, right now my car feels balanced to some extent with the stock front and an outback rear. I like its balanced feeling but going to upgrade both again at some point.

strat81
01-31-2007, 06:04 PM
matching bars should make the car feel neutral... (all 4 wheels break traction at the limit)

bigger bias to the rear should promote oversteer.

bigger bias to the front may promote understeer.

Reason
01-31-2007, 06:08 PM
Thanks Spencer, that's what I wanted to know.

scottzg
01-31-2007, 07:40 PM
a larger front bar will improve grip in steady-state turning but make the car understeer more with weight transfer.

a larger rear bar will decrease grip in the rear, especially while turning.

as the bars becomes relatively larger than the springs the car will be more unsettled by bumps and in my experience becomes much more difficult to control in big slides and corrections. The car will also become less pleasant to drive hard at higher speeds, all else being the same.

a common practice is to put a big front bar on in order to take advantage of the extra grip it produces (by keeping the outside tire more vertical) and then put an even larger rear bar on so the rear of the car still unhooks with weight transfer. It works and it rides good, but i'm not that crazy about it.

OutbackGT
01-31-2007, 11:28 PM
I second the 20/22 strategy. I'm running stock/22 and I can get seriously tail happy, especially when the roads get slick or I'm on gravel. Going 20/22 would probably be ideal if you're looking for neutrality. Of course ideally, I'd like to go something like 24/28, but they don't make bars that big for our cars!

Reason
02-01-2007, 01:34 AM
What about 22 front and 20 rear?

MCarp22
02-01-2007, 06:14 AM
What about 22 front and 20 rear?

That would probably balance out pretty well. Most people would expect my 22/16 combo to understeer into oblivion, but the extra front grip seems to keep the car happy.

Wiscon_Mark
02-01-2007, 10:33 AM
What kind of tires do you use? I bet that helps. Extra traction in the front actually means less understeer.

Usually a bigger bar in the front means you stiffen up the front and lose traction (due to bad tires or whatever) quicker, which gets you more understeer.

rougeben83
02-01-2007, 11:52 AM
Increasing the front bar size on subaru's actually helps reduce understeer due to the reduction in geometry changes to the MacPherson strut suspension from hard side to side loads (hard changes will actually change the toe and camber, affecting the scrub radius of the car...one disadvantage of the MacPherson strut).

I have 19mm/22mm in mine, only change in the front are stiffer bushings and endlinks. Not very tail happy at all.

Play with the tire pressures a little bit to fine-tune how the tires breaksaway and you can help compensate a little bit for whatever bar size combo you use.

sheepdog
02-01-2007, 12:16 PM
I prefer oversteer to understeer any day of the week.... I run 18/24 on the GC, with the coilovers set stiffer in the rear :lol:

strat81
02-01-2007, 06:28 PM
oversteer isn't a bad thing if you are a capable driver... too much oversteer can be a bad thing though.

i had the outback bar in my wagon and a rear strut tower brace and it helped with the cars willingness to turn in. IMO, a front bar was still needed though cuz you could feel the front end of the car sway while the rear stayed more level in a turn.

tires do play a big part too. if you have a good suspension but crap tires, you'll just overwhelm the tires. a chain is only as good as it's weakest link.

i have matched bars (25.4mm addcos) on my cavalier (different car but same basic principle) along with springs/struts, and strut tower braces. i had just the rear bar for awhile before i got the matching front (factory front is 18mm) and that got a bit scary when the tires did start to break traction because the rear would rotate pretty quickly (caught me off guard at least once) once that happened. i also ran with upgraded endlinks and bushings on the factory front and it helped some but the matching bars have been the best setup yet.

when i go to do the wrx, i'm considering going with an adjustable set. i've read some good reviews about the adjustable bars because the car can become twitchy at speeds with too high a thickness. with the adjustability, it would not only allow you to dial in the car for your driving ability/preference but would also allow you to step it up for autox or track day events...

Reason
02-01-2007, 08:05 PM
Yea I will just end up going with adjustables so I can find out what works best for me. Thanks again guys, great help!

scottzg
02-02-2007, 12:29 AM
Usually a bigger bar in the front means you stiffen up the front and lose traction (due to bad tires or whatever) quicker, which gets you more understeer.

a larger front bar will improve grip in steady-state turning but make the car understeer more with weight transfer.

its really not that simple. In my experience (having run A LOT of tires) which tires you have on there don't really affect the way the car balances, just how soon you reach the limit. Good tires feel understeer proof at first because you expect the car to understeer and it doesn't; once you get used to more traction, it understeers just as much.

rougeben83
02-02-2007, 06:34 PM
Usually a bigger bar in the front means you stiffen up the front and lose traction (due to bad tires or whatever) quicker, which gets you more understeer.

a larger front bar will improve grip in steady-state turning but make the car understeer more with weight transfer.

its really not that simple. In my experience (having run A LOT of tires) which tires you have on there don't really affect the way the car balances, just how soon you reach the limit. Good tires feel understeer proof at first because you expect the car to understeer and it doesn't; once you get used to more traction, it understeers just as much.

Yes, stickier tires doesn't change the car's behavior at the limit, it just moves that limit up a couple of more notches.

Wiscon_Mark
02-02-2007, 06:35 PM
Right - a softer suspension will make the limit less of a cutoff point - but good tires will keep that cutoff point from happening during normal driving situations.

strat81
02-06-2007, 07:02 PM
Usually a bigger bar in the front means you stiffen up the front and lose traction (due to bad tires or whatever) quicker, which gets you more understeer.

a larger front bar will improve grip in steady-state turning but make the car understeer more with weight transfer.

its really not that simple. In my experience (having run A LOT of tires) which tires you have on there don't really affect the way the car balances, just how soon you reach the limit. Good tires feel understeer proof at first because you expect the car to understeer and it doesn't; once you get used to more traction, it understeers just as much.

Yes, stickier tires doesn't change the car's behavior at the limit, it just moves that limit up a couple of more notches.

not completely true... some tires lose traction more linearly than others... regardless of suspension... some break away progressively while other tires can completely let loose at the limits...