Mark IV anti-sway bar question

[montyals]

Regarding rigidity and handling, does the Mazda anti-sway bar fit the Mark IV chassis? If so, which year? If not, is there an after market recommendation? Thanks!

[Jeff Kleiner]

It will fit but let me ask this; what are you trying to accomplish by installing a front bar? What type of rear suspension and what spring rates front and rear? Are you coupling it with a rear bar? The reason I ask is because with the FFR supplied components the cars have a natural tendency to understeer. Stiffening the front (i.e. installing a bar) with no other changes will exacerbate that condition.

Jeff

[CraigS]

I have used the Miata bars but in the end went w/ a front bar from Forte. He has them available in three different thicknesses.
http://www.fortesparts.com/index.php?cPath=57&sort=2a&page=2
I autocross a lot and am running the 7/8. For street only I would probably run the 3/4.
These guys have very nice rear bars for 3 link or IRS
http://www.vpmcobras.com/

[montyals]

Thanks All. Jeff, I plan to autocross next spring/summer and was looking to prep the car over the winter. I was figuring that increased rigidity might not be a bad thing. I have a 3-link now. I have the stock Konis that came with the kit. Thanks for the heads up. Next year will be my first time auto-xing the Mark IV, assuming we have the exact same set up, I wasnt aware of the potential for understeering.

[Bob Cowan]

For autocross or open road, I would do two simple things.

First, increase your suspension frequency to about 2.2 - 2.4. The easiest and cheapest way to do that is with some "heavier" springs.

Second, add an adjustable sway bar. I think it's important to use a bar with at least a moderate amount of adjustability. The springs will get pretty close to where you want to be. Then you can use sway bars to do the fine tuning by adding wheel rate in small increments.

Simply adding a bar from another car with zero relationship to your car is a guessing game at best.

My car has IRS. I use 750# springs in the front, and 850# in the rear. Then I use a VPM bar in the front, at max rate. And a VPM bar in the rear with a small amount added rate. I can get a really close balance on almost any track. Even with aero added on.

On the street I disconnect the bars completely.

[montyals]

Thanks Bob!

[CraigS]

What tires will you be running for AX? they have a lot of bearing on what springs and bars you will need. More grip requires more stiffness. I autocross in the DC area w/ several other FFRs and there has been some experimentation going on this past summer. At least I have been talking to Wade and trying some of what he has tried. He was trying to figure a way to get the power down better and tried disconnecting the rear bar. SO I tried it too and wasn't happy w/ the steady state understeer. Got to the next AX and noticed his front tires seemed really leaned in at the top. He had had the same understeer so went from approx. 2.5 to 3.0 degrees negative camber. naturally I tried that too. Any way, I would get the forte 7/8 front bar and the vpm rear bar for 3 link. the latter is expensive but can be adjusted between AX runs and has been a great asset. If you will be on good street tires, I would stay, for now, w/ the FFR supplied springs 550Fr and 350 Rr I think. Run next season on the street tires, get experience to decide if you want to continue to another level or not. If so, next winter get a set of A6s on another set of wheels and up your front spring rates to something like 700-750.

[Jeff Kleiner]

...decide if you want to continue to another level or not. If so, next winter get a set of A6s on another set of wheels and up your front spring rates to something like 700-750.

And the rears to 500#

Jeff

[montyals]

Craig/ Jeff, thanks. You raised some good points Craig. Next year will he spent getting to.know the car's baseline performance and building on that if ne necessary.