Looking for new sway bar. Can I go too big??

MRGTX said

I try to relate some of the stuff I've learned from bashing Miatas around autocross courses...and high school physics class too. :D



The biggest benefits of sway bars, IMO is improving driver confidence. If properly matched to spring rates and properly tuned front vs rear, they can certainly improve lap times too but a sway bar does not net any traction gain. It merely controls where the load is carried.
In a turn, a sway bar reduces load on the inside wheel and increases the load on the outside wheel. As we know, increasing the load on the outside wheel does not increase friction proportionately. On the contrary, it results in a net loss of grip.

How would you correct for a car that is understeering? If you say "stiffer sway bar," I don't know what to tell you. Just give it a try....then log into the forum from the bushes while you wait for the wrecker and let us know it went. :)

Ok. Fine... In a case where your car is losing grip due to excessive positive camber under load, increasing sway bar stiffness and decreasing compression of the outside suspension can correct for this geometry problem and improve grip. Maybe that is a relevant concern when looking at factory alignment specs on our old cars.

Click to expand...

If you don’t think that controlling where load is carried on the suspension effects your traction, your high school physics teacher failed you miserably.

You say you’re not adding traction, well, that’s a silly way to look at it. By that definition only tire compound will ever add to your traction. All any suspension is ever doing is keeping you from losing traction. So just run without it, it’s not adding traction by your logic.

And why do you need to improve an understeering car with a stiffer sway bar? That doesn’t say anything about what a sway bar does. Sure, you can be in understeer if you’re already too stiff in the front, and adding front sway bar won’t help that. But that doesn’t mean a sway bar can’t improve traction, it just means they’re not always the solution to a particular problem. Of course, you could be in understeer because your front suspension is too soft and you’re bottoming it out on braking and entry, in which case adding wheel rate might actually help. You’re vastly oversimplifying, and your own “camber issue” example shows that. There’s a lot of possibility’s that you’re just flat out ignoring.

As far as improveming lap times, improving traction is the number one way to do that. If driver confidence is a bigger factor then it’s inexperienced drivers that’s the problem. Which is exactly what you see in Miata racing, because that’s entry level competition. So yeah, maybe a bunch of inexperienced drivers like you’re used to seeing just use sway bars as their magic feather, because they don’t have a clue what’s actually going on. Might not want to use them as your example.