Sway Bars - How they work and how to choose the right size for your needs

[Hans[93GT]]

It really depends on the rest of your setup, especially your springs

[pgt95]

So hans since your the resident guru.... what do you think about tokico springs/struts and a 626 RSB on a daily driver that enjoys running windy roads in ohio in its time off?

No pressure i will make my own descision, but if oyu see any immediate short comings i am all ears

[Hans[93GT]]

I have never driven or even riden in a car with Tokico springs, so all I know is what other people here say about them, and what Tokico claims about them (they say their rate is 170 front, 140 rear, which, if true, is softer than a stock PGT (187, 146)

But one guy here said they actually felt STIFFER than stock, so who knows what the real story is.

All I'm saying is that if you took any springs and struts and put them together, Tokicos have the best chance of being well-matched.

It's what I'd buy, and yes the 626 bar is what I'd buy too. Remember, at 16mm, the 626 bar is the same size as the old Mazdaspeed bar, and Mazdaspeed knows their shit

[Pintoracer]

ok. got a couple questions. I NEED to replace the endlinks on my probe(rear) and looking at prices I have been considering getting a new sway bar kit and just doing the whole thing.
suggestions?

Sorry to respond to this so late. I haven't been on this forum in some time. The cheapest thing for you to try is go to a wrecking yard & buy a stock sway bar with good end links. Replace your bad links with the used ones. You can then attach the wrecking yard bar to your existing bar with cable clamps from a hardware store. This is an old trick I learned in my autoxing days in he early '70's. I put one on my '93 PGT a little over a year ago. The car went from the usual Probe understeer to being fairly neutral with a slight understeer in really hard slow speed corners like turn 11 at Infineon Raceway. The rest of the suspension is stock except for a little negative camber. The placement of the clamps is very important. A friend has a picture on his computer. I'll have him e-mail it to me so I can get it posted. The whole thing cost me about $25. I didn't get the links 'cuz mine were good.

[pgt95]

So you are in effect strapping the tqo bars together? How is it fitting by the center mounts near the frame?!?!?

[Pintoracer]

So you are in effect strapping the tqo bars together? How is it fitting by the center mounts near the frame?!?!?

Yes. The second bar rests against the mounts. If I ever get the picture from my friend I'll post it.

[MyMellinie]

So if I now have a 18 mm bar and before there was no bar at all, how would this be calculated besides vastly better?

M

[Norm Peterson]

The actual stiffness of the bar (rather than just its comparative stiffness with respect to another bar bent into the same shape but of different diameter) can be computed if you know a few more things about the bar than just its outside diameter(s), plus a few engineering structural analysis formulas. Then you need to determine what effect this additional rear roll stiffness as seen out at the tires has on the distribution of the existing total roll stiffness. Obviously, your TLLTD will shift rearward, but whether that's by a couple percent or more like ten percent depends on how much roll stiffness that your car's suspension has already. For most stock-ish cars, you can read that as anything from "less push" (if your car has quite a bit of roll resistance already) to "loose" (if it's soft enough to roll like a boat in a storm when pushed through the corners a bit).

Whether adding that much rear roll stiffness without stiffening the front slightly at the same time would actually be better may well be up for grabs. It's possible that this would loosen up the handling too much for individual comfort, with the unintended result being that you'd drive *less hard* just to stay out of the region where you no longer have confidence that the rear is going to remain behind the front. Trust me, there IS such a thing as being too loose.

Or, given that it's possible to have enough rear roll stiffness to lift the inside rear tire clear off the ground, there becomes a point at which it makes no difference how much rear bar is there, as 100% of any additional Lateral Load Transfer will be resisted up front. The car might turn in better, but at some point (perhaps depending on the duration of steady-state cornering) tripod-style cornering will give back any transitional gains.

Norm

[Hans[93GT]]

Not to mention that big swaybars put lots of stress on the endlinks and mounting tabs when you turn up the ramp into a gas station or driveway. Several people have busted the tabs on their control arms because they didn't slow down enough while doing that.

[Pintoracer]

Or, given that it's possible to have enough rear roll stiffness to lift the inside rear tire clear off the ground, there becomes a point at which it makes no difference how much rear bar is there, as 100% of any additional Lateral Load Transfer will be resisted up front. The car might turn in better, but at some point (perhaps depending on the duration of steady-state cornering) tripod-style cornering will give back any transitional gains.

Norm

Norm, in all my years in road racing I never heard the term "tripod style cornering." I'm always willing to learn new things so could you elaborate?

[Hans[93GT]]

It means when one of the wheels (in this case the inside rear wheel) is hanging up in the air because it doesn't have enough suspension travel to extend back to the ground. Thick swaybars are often responsible. So are primitive trailing-arm suspensions like early VWs.

[Rocko]

Dan, if this is a stupid question just yell at me....but im just trying to check my understanding and put it in a simple format for my own dumb ass

basicaly....the thicker the antisway bar you put in the rear...provided proper strength and stiffness or whatnot (proper construction) the more towards oversteer you will place the handeling tendancies of your car?

[Norm Peterson]

Simplified: if you do not change any of the other dimensions of that rear bar, the thicker you make it the stiffer it gets. Assuming that no changes were made to stiffen the front suspension, it's the now greater rear stiffness against roll that brings with it anywhere from slightly less understeer to wild oversteer depending on how large of a rear bar stiffness change was made.

Remember to think in terms of stiffness, as it's the stiffness that matters (load is attracted more toward where it is greater). Comparisons based on thickness alone are valid only if the bars being compared have otherwise identical shape and are mounted in the same fashion. This may be a fair enough comparison for discussion of otherwise similar bars intended to fit one specific car platform (e.g. Probe/MX-6/626, or GM G-body), but thickness by itself is not enough information for comparing bars that differ in other ways as well.

Norm

[dancindeny]

i have a 96 pgt. if i change the front sway bar, do i have to drile new holes in the A frame for the links.
thank you i am new here

[Dan [Sac]]

You won't change your front sway bar. Trust me on that one, it's not removable unless you drop the entire front subframe, including lower control arms. Also, no one makes aftermarket front bars for the Probe. You don't need them. The car understeers heavily out of the box, adding a bigger front bar makes things worse.