Are sway bars worth it?
 

For those with sway bars, do you guys actually feel a difference when driving compared to not having a sway bar? I already have a decent shock/spring combination (Bilstein B8 w/ RCE Tarmacs) and I want to do more to my suspension so I'm looking at sway bars.

Do you guys honestly believe that sway bars are worth it?

All depends on what the end goal is.
Daily driving, you're better off with better tires.
If you track/autox it on the regular it makes a noticeable difference.

Depending on what you plan on doing with the car. Yes, they are worth it compared to the stock sway bars.

Correct dampers and spring combo first, then sways "if" you need to tweek more than the dampers let you.

Sway bars are a cheap bandaid solution for sub par shocks and springs.

Thicker/stiffer bars tend to sacrifice grip for handling characteristics.

Opinions may vary, track times do not.

Sway bars are used in our cars by the factory and they are not a band aid solution. They make handling worse only when the sizes and stiffness rates of the bars are going beyond reasonable limits. In fact they are a nice alternative if you want to have a relatively comfortable suspension on straights without much roll on corners. Good solution for a weekend fun and occasional race track car. People don't use them too much, because they want usually at same time to lower the car and in this case they don't work alone without changing the spring lengths and rates.

As with most things, it depends.....
They can make things worse in some situations

It really depends on what you want to use your car for.

For example, my Impreza has aftermarket suspension including upgraded sway bars. The setup is a great match for my driving style when I compete in autocross since it is adjusted and set up to drive the way I visualize the movement. But you gotta research and make sure the sway bars don't make the setting worse based on both handling feel and actual time result.

My stock tS feels great as is and it is my weekend street car so I don't see myself changing the suspension. Again, it really depends on your end goal for the car.

Also, I agree with Mr. ac's comment. If the car is just for daily driving, you are better off upgrading the tires. Sound advice right there.

I think the car NEEDS sway bars when you upgrade the tires, cause the added grip adds a lot of roll. Even on stock suspension my car turns harder, is more stable through transitions, and puts more power to the ground with sways.

I have the Perrin 19mm front and OEM 16mm rear. Definite decrease in body roll without adding too much discomfort.

I used to have the tarmac springs/Bilstein b6 with a hotchkis 25.4mm and it was rough AF so heed others’ advice on how going too big can be a problem.

A stiffer rear sway bar will decrease the amount of power you can put to the ground in a corner... go too big and it'll lift the inside rear tire and REALLY limit how much power you can put down.


Sway bars should be a fine tuning aid, not the first solution to increase roll stiffness.

I have suspicion that fight for decreasing roll often is done more to boost driver confidence to push more, not so much to actually improve suspension.

Too many people put on larger rear bars to counter understeer and they end up chasing their tail. Some don't know how to rotate the car with the brakes and put on a thicker rear bar and call it job done

It is known.

Where's @Captain Snooze?

Yes, But sway bars are really an "end of mod" purchase. to effect balance from the front and rear.
I have a 22m front and 18mm, rear but i also have springs, shocks, bracing, bracing bracing, tires, brakes, and more bracing.

And currently to help prevent front wheel scrub I have the front full stiff and the rear set to middle. Too much rear sway makes the car unstable on throttle on exit, now that I have the wing I might change that but again

it's an "end of mod" item.

As it was mentioned, feel out the car with proper shocks and tires and have it tell you what it needs

Here I am!
Not much more to add.
For quite some time I was not using any bars on 6k/6k springs and 9k/10k springs. I am only using the oem sways on 7k/6k springs now because the damper maker was weirded out that I was not using sways with his product.
Too big an anti-sway bar is definitely a bad thing.



Because compromise.

My opinion as well. I think while some sway bar tweaking stands to improve grip by changing the chassis dynamics to be less easily unsettled, where the unsettling would create unexpected understeer. But I'm of the opinion that sway bars don't change the physics of tire grip. In some cases, you want the inside tire to droop and maintain a little grip which would be a looser sway bar.

It depends on your spring rate. I wanted to stuck with soft springs for comfort, in which case the stiffer bar keeps you from rolling off the contact patch on the outside tire.

I'm not running crazy bars, just the Perrin 19mm front and 16mm rear. I'm also not saying they're a cure all. I just wanted more roll stiffness without touching the springs. They're definitely a fine tuning tool to get the car to rotate to your preference.

But did you prefer running without sways long after your first impressions? Would you do it again?

It is worth it to buy the used Whiteline bar I am selling. Definitely.

It was a learning experience. I didn't know what I was doing; I thought bigger sways equaled better. With the 6k/6k set up the sways were too much for the springs. That is, I could feel the cross talk at the front. I did not use sways with 9k/10k springs.



For my noob/amateur needs I would much prefer not to use sways because of my experience with using too much anti-sway. That is, I think using higher rate springs with good damping is less of a compromise. (Yeah, there's that word again.)

Disclaimer, I'm a suspension noob.

It seems to me that 2 benefits of anti-sway bars are that the car takes a set quicker in a corner and it helps maintain front camber in a car with McPherson Struts. Not to say that you can't do that with stiffer springs (which should also reduce dive and squat), but that could compromise performance on a bumpy surface.

I think you pretty much have it. It applies for normal passenger cars - which, of course, the 86 is - but how much do they help when you're already in the bump stops?


I've been taking my sweet time feeling out the stock setup. Time for me to pick a direction. RIP, checking account. :brokenheart:

Spuds: antiroll bars don't do a thing for dive & squat. They act as extra springs only in case of roll, when one side wheel is bumped. With mass transfer to front and rear, when both wheels go up or down together, swaybars simply freely rotate together with them.

You might want to re-read my post... I said stiffer springs affect dive and squat. Anti-sway bars do not.

I could be misunderstanding how this works, but if you are hitting the bump stops in a corner your suspension has more problems than the wrong anti-sway bar size.

You and me both... Im happy with the stock setup, but how would I know if there's something better if I don't experiment. But that's a whole lot of time and money...

Right? Ugh... At the same time, if I was made of money, I feel like I'd take it all for granted.


I don't know how common the practice but this one was designed to ride the bumpers when loaded up. It's a so-so compromise until consistently driven above 7/10-ish. Then it's annoying. Bilsteins are looking good lately.

Spuds: oh, sorry, i was too inattentive quick reading through it.

Regarding hitting bumpstops, of course right way would be to match springrates to tire grip and driving style, then stiffer swaybars. I actually don't get why swaybars are such popular aftermarket item to be bought/installed, especially without doing lot of homework first if needed and which needed or consulting pros/competent shops. And often it seems that they are bought not for specific handling change, eg. fine tuning grip balance, but rather by "aftermarket parts are better", "bigger is better", "they cost less then coilovers".
But in general, IIRC such soft springrates+bump-stop active suspension setups as on ours stock, are rather popular on current cars, giving a bit more comfort/compliance for daily driving. Yes, suboptimal for suspension performance when pushed at limits, but with it's cons/pros viable choice in eyes of many manufacturers, mostly thinking of daily driving performance, when choosing compromises.

As i'm suspension noob too, i prefer to simply reuse setups of similar use that worked well for people with more clue/experience, or do changes according their advises on what i want to achieve, instead of blindly throwing aftermarket parts in suspension, and at most finding placebo improvement for sake of justifying purchase. My own lacking skills and consistency certainly cannot serve enough to properly evaluate changes. You noted well, that proper testing needs time and money .. i'd extend that also with skills ensuring consistency for proper testing and experience to know if/what/how/to what extent needs to be changed instead of trying out every possible combination if better or worse.

I cross a nice perpendicular pavement gap in a long left-handed downhill sweeper. It limits my approach enough that I have to let up on the wheel to distribute the "event" evenly to the chassis, and then lean back into it. It's my adopted test corner.


Also maths.


https://i.imgur.com/F0WYURn.jpg
https://i.imgur.com/zJgpq0Ml.jpg

I realise that swaybars come standard, I was talking about aftermarket bars, where people tend to go stiffer "because" they don't actually understand what is required, generally.

Opinions may vary

As others have said, sways would be my last stop on the suspension odyssey. Getting them right is not entirely straightforward. If I had managed to build a good wheel/tire/shock/spring/camber/everything else setup and the suspension(body roll) was still preventing the car from doing what I wanted (and was able to correctly ask) it to do, I'd either hit the books hard or get advice from someone who REALLY knows suspension set up.

For what its worth, I think I have an experience worth sharing.

At my last time trial, a week ago, I disconnected the front sway bar to try and get rid of some unwanted understeer I had picked up after my spring rate change from last season. Funny things happened, the first interesting (and expected) thing was the car had more grip on steady stat cornering, but was a bit more sluggish changing directions, which hurt quite a bit on S type corners. The second, less expected problem was that the car was lifting the inside rear wheel during cornering. So at the moment of getting back on power I was getting a lot of wheel spin on the inside tire and losing quite a bit of time there. Even tho the data shows higher mid corner speed, the car was actually slower over the whole lap, losing quite a bit of time on corner exit (probably due to spinning a wheel).

For those curious, I was pushing quite hard, not just doing parade laps (start at 2:30 to skip the warm up lap). This is with the sway bar, best time is 1:44.1, best time with sway bar off was 1:45.6

[ame]https://www.youtube.com/watch?v=IjzuZ60W0CE&t=150s[/ame]

Lifting the inside rear isn't unexpected IMO. You softened up the front roll stiffness significantly without undoing the rear bar, so the car is rolling onto the outside front tire much harder while the rear bar keeps the inside rear tire lifted.

You are right that it wasnt probably unexpected for most, but it was for me, as the car has quite the stiff spring setup and quite a bit of downforce (not into the thousands pounds, but not that far). To think that just undoing the front bar will completely lift of the ground the rear kinda did caught me by surprise. Its not a shoft wheelbase hothatch after all.

Never heard of anyone disconnect a sway bar at the NON-driven end of a 2wd car in an attempt to go faster at the track! Not surprised it didn't work... but good on ya for trying something absurd, sometimes worth a shot when in a bind and at least you learn something.

The fastest 86 I know of in my region is has (or had?) the front sway bar removed. it is a fully built car for WRL. I don't know much about the car, but anti-sway bars are just one of many variables in setup.

The answer is of course "it depends." Love that answer.

In the early Subaru USDM WRX and STI days, the choice was often presented as "soft springs and stiff bars" or "stiff springs and soft bars" for most track cars and autocrossers. The latter meant good quality coilovers so that the ride wasn't crap, which meant you needed a bigger budget. It was the better choice, but you really could just thrown on a bigger set of swaybars for 400 bucks and it was a massive difference over stock for those understeering pig cars. Of course a lot of people started going way too big and found the limits of that tuning philosophy when cars with reasonably stiff springs and reasonably stiff swaybars were faster than them.

Subaru increased the rear bar size ever so slightly on BRZs in 2017. Does this mean that bigger bars are better? No. It means that they decided that they wanted slightly more front grip than they did on the previous cars. They could have increased front grip by increasing rear spring rate (could alter ride and pitch characteristics too) or decrease front spring (also alter ride and pitch and result in more bumpstop engagement) or more front camber (much more complicated on their end than it sounds) or a variety of other things. It's not necessarily the best way to increase front grip, but for them a rear bar size increase of 1mm was an easy, cheap, and straightforward way to achieve what they wanted to achieve.

With regards to bumpstops, these cars are very bumpstop active. You're well into your bumpstops when you hit the brakes hard and turn into McDonalds and get a BigMac with a large fry and a liter of cola AND you very well could be into your bumpstops when you just sit back down in your car after your done eating. It's designed into our cars (and many other cars) stock.

Swaybars (and bumpstops) can be used in different ways by different tuners and OEMs...the important thing is that the complete package is considered when making any changes.

- Andrew

How so? They've sold cars with adjustable camber bolts before (definitely STI's had them), the OE struts are sized for them, it would be cake to toss a pair in and have them roll off the line with -1.2° or so...

Edit: your comment about 'stiff sways soft springs' vs 'stiff springs soft sways' is really relevant to the discussion imho, there's a middle ground and a mild upgrade from stock that's reasonable that some people will like, some won't. Good luck OP.

I think the difference is a new rear swaybar is just a new part they use in assembly, whereas camber bolts require a new part number AND some adjustment during assembly. Not much, but enough that it's an additional process.

Mitsubishi EVOs had a 2 postion camber bolt on their front struts that was either -1 or -2 degrees. All were assembled the same way in the -1 position. It was simple and effective for an OEM and man I wish Subaru did at least that for the BRZ.

Agreed!

- Andrew

Would you ever ditch the sways in favor of higher spring rates? Is that just crazy talk?