Swaybar upgrade worth it?

[rumsawatti]

I was wondering if aftermarket sway bars such as godspeed/tanabe are worth getting and if a noticeable difference will exist on a stock DD, car doesnt get tracked at all, just pushed a bit on enticing corners/roads near home for fun . But if its any kind of noticeable difference I wouldnt mind buying them. However, I dont want to pay over 100$ for two metal bars that would only make a difference if I was going for a fully built suspension/track car. Anyone know the sizes of the stock bars? All I know is they are tiny little things.

[Deuce Cam]

Stock gts front is 22 mm and the rear is 16 mm.

I went from stock with prothane bushings to whiteline adjustable bars front/rear, then cusco front and whiteline adjustable rear, then cusco front and stock rear, and finally back to the stock bars with prothane bushings . I always ran the whiteline adjusable bars at full soft.

It's really a matter of preference. All are perfectly fine on the street with some fun. A larger bar will reduce body roll as advertised.. IMO the larger bars slightly increase steering effort, and create a more twitchy and teetery feel(for the lack of a better description) when turning the wheel from its center point. The rear seemed a little more stable with the whiteline adjustable bar vs. stock.

The whiteline and cusco bars may be better on a track, but I prefer the stock bars for street. They do the job, and the overall feel, especially steering feel, seems better imo.

[rumsawatti]

Thanks, The info was great! So I'm assuming its not a huge difference between any of them? 22mm stock sounds like a good deal, however something thicker on the back might be a little more exciting and possibly noticeable even for daily...Right now I have a rear with prothane bushings and a toothpick sr5 front, i was debating either buying front prothane bushings or an entire aftermarket front and rear set.

[phanist]

i got tanabe bars front and rear... i love how it feel cornering

[carbd7age]

I think I remember reading on the old auto-x forum that a lot of the hardcover auto-x guys ran no sway bar in the back? Is that true or did I just make that up and ruin the internet?

[gotzoom?]

When comparing swaybars, keep in mind the Godspeed swaybars are hollow, so the outer diameter comparison to solid bars is meaningless. I never drove my car in anger with anything near a stock suspension, so this is just my observation on a track suspension extrapolated to how it might work on the street.

The stock swaybars are too soft for any kind of performance driving, imo. The front bar makes the car tend toward oversteer and even snap oversteer. The rear bar is too soft to make enough springrate difference to effectively control the rearend. It is stuff enough to further restrict the rear suspension motion so that you pick up an inside rear under the type of cornering load you experience autocrossing, so disconnecting it is a good idea for autocross. You need the extra cornering springrate on track, though, so you'll want some rear bar on track. I don't like the way the car handles on track with no rear swaybar.

Getting back to the road, swaybars have little if any effect on normal road driving quality. If you use the stock endlinks (with new bushings) or Prothane replacements, you shouldn't notice much difference in noise either. The added roll stiffness should make the car feel more responsive and confident when cornering. I wouldn't expect a dramatic change, but they should make the car a lot more fun. If you're using full stroke shocks/struts with shorter springs or cut springs, they should help keep the unloaded side springs seated better and reduce the clunking sounds as the car sits back on the unloaded springs. For a stock suspension car, I'd say they are are a worthwhile upgrade. I've used Godspeed swaybars on my car and I think they are a good choice for the road. They are a little soft for serious track duty, though. One of the really appealing things about them is that they are hollow and therefore much lighter than solid bars. Unfortunately, they chose to paint them rather than powder coat them, so the paint will come off under the bushings pretty much immediately and if you're not careful installing them. I hope that helps.

[nohachi]

@Gotzoom? How do you reckon the *front* bar tends toward snap oversteer?

Your swaybars on a stock AE86 are a BIG part of the overal handling equation!! The fronts add about 2.4kg/mm to the front roll rate (good) and half that to the one wheel bump rate (bad). That's as much as or more then the front springs! The rears come in at 1.1/0.5kg/mm which is significant and definitely more then just enough to limit droop.

Aftermarket sways add about 50% (cusco and tanabe == same thing) so its the equivalent of slapping 4kg/mm springs on the car in roll.
Depending on the roads you hit this can be a good or bad thing. The sways couple the left and right wheels together, no problemo on the rear, but tends to produce head shake on the front (sort of left right jittery movement). Swaybars have no effect on steering whatsoever.

[Deuce Cam]

These are all good points. Larger sway bars will give the car a more sporty feel since there's less body roll. They're a great alternative for a street car with low spring rates. You will notice a difference in performance with the larger bars right away.

From my experience the larger front bars seemed to increase understeer a little, but larger bars aren't a bad thing, especially on macpherson strut (fail) equipped cars like the ae86. Personally I'd rather run higher spring rates and use the smallest bar possible.

Stock sr5 front bar is 21 mm I think.

Swaybars have no effect on steering whatsoever.

Before I would have agreed with you, but after switching from the cusco front bar back to stock I can say that there's an ever so slight difference, which is a benefit on a manual rack equipped car imo. I didn't expect it, but it was noticeable right away.

[nohachi]

Deuce, then you might have some preload somewhere that's affecting toe or maybe its the quicker loadup you're noticing.

Swaybars are springs, keep thinking of them in that manner. Add spring rate to the front of a balanced car and you get more understeer, add rate to the back and it tends towards oversteer.

Normally you wan't everything in proportion. Stock about 50% of the total rate comes from the swaybars, if you quadruple the spring rates you can at least double the bars as well. Running no rear bar with the solid axle is also an idea worth pursuing. But you have to add rear spring to make up for the loss of spring rate (or dick around with the roll centers, but that's a whole different ball game).

[gotzoom?]

I mostly track my car, which means driving it on the limit of adhesion. For normal road driving, I agree that you will not notice any difference in steering, regardless of what bar you run. At the limit, the swaybars make a big difference in steering. The front bar is way to small for track use. The grip balance is out of whack and the car tends to oversteer, even to the point of snap oversteer. If you run a larger front bar, the added roll stiffness reduces front roll which in turn makes the car not turn as well. It also has the added benefit of helping keep the inside rear tire on the ground. It basically gets you back to a more neutral grip balance which makes the car a lot more managable on track.

[Deuce Cam]

Deuce, then you might have some preload somewhere that's affecting toe or maybe its the quicker loadup you're noticing.

Doubtful on preload because I always tq. the prothane endlinks to factory spec. I always change the sway bar with the car on the ground and unbolt the tension rod brackets from the chassis and rods from the control arm leaving the caster adjustment on the rods unchanged. Still, there's a little play in the mounting points to allow for slight alignment change.

Perhaps it's the quicker 'load up' I'm noticing. If it helps the difference is most noticeable when moving the steering wheel back and forth really quickly when driving. The steering just has a more progressive feel with the stock bars imo. On the downside with the stock bars the response is a little slower and there's obviously a lot more body roll. I realize what I'm describing the the suspension reacting to steering imput. This can be felt through the steering wheel on the street; one doesn't even need to be driving fast.

[nohachi]

Could also be a bump steer effect, that becomes more noticeable with the higher roll rate.