Alphadawg
Alphadawg New Reader
7/14/14 3:22 p.m.

I have a 95 that I am running in E Street. I installed Koni sports with the stock springs. Installed Dunlop ZII with a good autocross alignment. Ran great but had a little bit of oversteer. A friend gave me a beefier front sway bar - Flyin Miata bar I think and I installed that last weekend. Now, at the autocross I seemed to have trouble with understeer. There was a particular left hand turn where I consistently had the front end pushing and had to make steering adjustments to get the front tires to grip again. Car just felt less tossable.

Is that a function of the new front sway bar? If so, what should I do to combat that? I installed the front bar just because I heard it was better and because I get a lot of lean - so much so that others have commented on it. Ideas?

iceracer
iceracer PowerDork
7/14/14 3:40 p.m.

Stiffening the front is the cause of your under steer. A bigger rear bar, or stiffer springs will help. You could try playing with tire pressures. Different front to rear.

Alphadawg
Alphadawg New Reader
7/14/14 3:44 p.m.

I have the Konis set to full stiff in the front and full soft in the rear. I guess I should increase the stiffness in the rear? Add pressure to the rear tires? I weas running 30 lbs all around. I am still new at this - thanks for the help

BoxheadTim
BoxheadTim GRM+ Memberand UltimaDork
7/14/14 3:51 p.m.

Either install both FM sways as they're designed to work together, or go back to the stock ones and deal with the lean. If anything, you're only doing fine adjustments with shock adjusters and that's not going to be enough to make up for the unbalanced sway bars.

kylini
kylini Reader
7/14/14 4:12 p.m.

Since you're running in E-Street, you're only allowed to change one bar. If you've already set your front bar to its "loosest" setting, I would slowly bump up the rear shock stiffness. This works great if you have a test-n-tune or a non-SCCA event with a ton-o-runs.

Whatever you do, try to only change one variable at a time or you'll get hopelessly lost. 30/30 isn't bad for tire pressures (I usually run 32/28 but that would have the opposite effect for you) and full stiff front isn't bad either. Rear shock settings is the "cheapest" way to play with your problem.

Alternately, reinstall the stock front bar and remove your rear bar. See how that works for ya!

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
7/14/14 4:47 p.m.

What's your actual alignment? Autocrossers seem to run setups that would understeer on the street, I think they make up for it by pitching the car in. But you'll want a fair bit of negative camber up front to make that bar work for you.

kevlarcorolla
kevlarcorolla HalfDork
7/14/14 6:18 p.m.

Basic rule of thumb,soften the end the slides 1st and stiffen the end that doesn't.Like Keith asked,what is your actual alignment #'s?.

I just took a JR front bar off (and replaced it with a hollow RB racing bar),too soft on the stiffest setting even with 800lb fronts and hoosiers.

I think you'll be able to get it working well with that bar,camber/castor/toe optimized and it will grip fine imo.For a good reference go to 949racings alignment guide.

Mr_Clutch42
Mr_Clutch42 HalfDork
7/14/14 6:46 p.m.

Since the car is only allowed for one upgraded sway bar, I would say to stiffen the rear shocks to get it into neutral or a slight oversteering handling balance. Like kylini said, just adjust one part of the car at a time to know the results of the adjustments. When it's good, fix the driver!

Alphadawg
Alphadawg New Reader
7/14/14 7:34 p.m.
Keith Tanner wrote: What's your actual alignment? Autocrossers seem to run setups that would understeer on the street, I think they make up for it by pitching the car in. But you'll want a fair bit of negative camber up front to make that bar work for you.

I am running the 949 dual duty alignment (or as close as they could get to it)

        Front camber: -2° (or as close as you can get to it)
        Caster: >4°
        Front total toe: 0

        Rear camber : -1.7°
        Rear total toe: 0 for track use. + 1/8" for autocross

So, if the basic rule of thumb is to soften the end that slides I should soften the front from full stiff first? I am just hoping to get it back to a little oversteer but without the excessive roll I had before. They finished a traffic circle near me - guess I better find a time when it is not busy!

kevlarcorolla
kevlarcorolla HalfDork
7/15/14 7:22 p.m.

Yeah crank the rears up and see,after that soften the fronts and see what changes.Fine tune from there if that's enough,I dunno as I haven't played with anything on stock springs in a couple decades.I've forgotten if the FM front bar is adjustable,if so soften it(hole closest to the open end of the U to at least test its effect.

BoxheadTim
BoxheadTim GRM+ Memberand UltimaDork
7/15/14 7:53 p.m.

Yep, the FM bar should be adjustable.

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