jdmtim

I have a set of FM sway bars for the front and rear. I searched around and read that these front sway bar can cause a lot of understeer. My question is has anybody install both sway bars and if so how was the ride? What hole setting did you have the front and the rear at?
I have a 94 miata R package with lowering springs. My plans for the car is some autocrossing and maybe a drift event nothing serious. Thanks for the help

Exofuji

I dont do any racing just lots of late night spirited driving. When I installed my FM sway bars I set the front to the inner hole. I notices immediately that the car tended to understeer a bit more than it did stock however I feel like the turn in was a bit more predictable. Excuse my ignorance.

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2ndGearRubber

Sway bars will have almost no affect on ride quality. Full soft front, middle hole rear; is a good starting place.

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stormin'norman

^ I would start by doing the opposite of what's listed above. Of course this is very generalized without taking into account the rest of the car.

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95montego

I heard of some people using stock rear sway and replace the front sway to accomodate for the understeer?

silvermazda

MEEEEEEEE TOOO^.
I'm about to buy some, so are the racing beat ones any good?
I disconnected the rear one during shock replacement, the rear rolls in corners, I guess I like a stiffer car.

scenturion

After going with the FM recommended setting (soft front, middle rear), the car would oversteer well before the traction limit [at the track]. Specifically, turn 2 at Thunderhill the rear end would always step out.
I used FCM's spreadsheet and showed that the front roll couple was much much too low with the recommended setup. I switched to stiff front, full soft (outermost hole) rear. This greatly improved the handling, im able to carry several mph more speed through T2, and when I do reach the limit of traction, it is very neutral.

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95montego

Sounds like the major sensus is RB tubular front as this is the thickest

eb66

x2 with stock rear

lebowski

If you install a larger anti-sway bar in the front without installing a larger anti-sway in the rear the understeering will make you miserable. There's no consensus as to which bars are best because it doesn't work that way. You need to decide what front roll couple you want for your driving style and setup and choose the bars on that basis, and that basis only.

Mobius

Spring rates play a role in the front roll coupling as well. For my car, with 9kg front and 6kg rear springs, replacing the front bar with the FM bar and leaving the rear bar stock put the FRC right at where it was originally. The car is very neutral and predictable on track, and I am very happy with the result. And I didn't waste upgrade monies, and I didn't waste any time trying to sort out over/understeer problems. Win.

jdmtim should play with the spreadsheet at FatCat Motorsports. Input your spring rates then find what bar you need to run.

For lightweight track cars with stiff springs, lots of aero, etc a common setup is the RB tubular front and the stock rear bars.

Also - and this is very important - make sure you know what your alignment is! Have the car aligned by a shop that knows how to align miatas. It's no good trying to chase oversteer by changing sway bar settings, if the oversteer's due to a crappy alignment ...

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NAautoxer

i have FM springs and FM bars. front is full stiff, rear is medium. car is very predictable/tossible/slightly tail happy at the limit. very easy to control

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2ndGearRubber

I like a loose car. I'd use that setup on a basically stock suspension, like the OPs. YMMV

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lebowski

That's one of the things I meant by "setup", but I got lazy and didn't really flesh out my description very well.

I think you've got it covered pretty well.

One other thing about anti-sway bars is that if too large they can reduce traction, and this is especially true on a bumpy road where the extra stiffness imparted on the suspension reduces compliance and increases maximum tire loads. If you substitute springs for anti-sway bars in the preceding sentence that's also true. It's best to know what your goals are and how to get there, instead of the too often used approach of getting what everybody else gets. Like Mobius said, the FatCat Motorsports spreadsheed is an excellent place to start.

1vicissitude

Idunno what this talk about sways won't effect ride quality, but when I put my RB hollow on the front my ride got significantly worse over uneven bumpy roads. Granted the RB hollow is a pretty big stiff bar, but it really made parts of the daily commute suck.

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lebowski

I would expect that too. A big sway bar means that when one wheel hits a bump or pothole, the other wheel reacts also, and that's not a good thing. A big enough sway bar makes your suspension approach a non-independent solid front or rear end; just like an old pickup truck.

1vicissitude

Exactly... I mean its great on smooth roads, zero roll, but if the road is uneven fuck that.

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gotxqss

Adding say bars and not cchanging alignment and or tire pressures will of course change the feel of the car. They arn't a install and everything is just more awesome part. Gotta play with it. Car will be more flat so the camber needed will be different to have tires on max patch. Front bar I like stiff. Rear soft or medium. Or maybe even none. Tire pressures can be a quik device that completely changes the characteristics of how the car feels. Just play around.

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jdmtim

an hour job is taking 2 days! wtf >__< tie rod needs to be loosen.. the sway bar isnt fitting at all...

stormin'norman

You're doing it wrong.

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jdmtim

I have the sway bars connected to the end link but the bushing holes aren't matching up to the frame

acedeuce802

Post a picture? It's pretty simple. There's really no reason for them to not line up, or to have to remove the tie rod.

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sdemo45

keep all the bolts loose until you have everything in its final position, then tighten. only thing I can think is that you have both end link bolts super tight and can't move the sway bar sufficiently.

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jdmtim

finally got it on just needed extra muscle to push back the bar so the holes will line up... next step should i install the rear sway bar or remove it

1vicissitude

I removed mine, but try with your stock on. See how you like the car.

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alangbaker

What holes my bars are set to is irrelevant...

...to your car.

If you're getting more understeer than you want, then you need to soften the front bar or stiffen the rear. That means a hole farther away from the pivot at the front and vice versa at the rear.