Oversteering Miata...help!

[storz]

So far I've done three autox events with the Miata, the first two the car was incredibly neutral and would just step out at the very limit, very controllable.

The car is riding on Bilstein HD shocks, Eibach prokit springs...the only change I've made from the first two autox event to this last one is a 1" Flyin Miata front sway bar with racing beat endlinks.

Conventional wisdom tells me that adding more front sway bar should reduce oversteer, on create understeer right?

Should I try removing the rear (stock) sway bar for an event?

Also somewhat related how do you remove the preload with adjustable endlinks? I can't get under the car to do anything with it sitting on the ground...

Thanks!

[milesj]

Aug 13, 2008 19:29:50 GMT -5 storz said:

So far I've done three autox events with the Miata, the first two the car was incredibly neutral and would just step out at the very limit, very controllable.

The car is riding on Bilstein HD shocks, Eibach prokit springs...the only change I've made from the first two autox event to this last one is a 1" Flyin Miata front sway bar with racing beat endlinks.

Conventional wisdom tells me that adding more front sway bar should reduce oversteer, on create understeer right?

Should I try removing the rear (stock) sway bar for an event?

Also somewhat related how do you remove the preload with adjustable endlinks? I can't get under the car to do anything with it sitting on the ground...

Thanks!

There are possibly some other variables. Were all 3 events at the same event site? Were weather condition comparable at all 3 events? Were you watching your tire pressures and making sure that the pressure was the same for all your runs at all 3 events? Did you take out the jack and related stuff for the 3rd event but not the first 2?

I have found that in my car, with no setup changes, that Knights is a little oversteery and Conti is a little understeery. There could be more to it than just your sway bar. Oh, conventional wisdom is not always right when it comes to sway bars.

Using a thicker sway bar makes the axle attached to it work better. Usually that means a thicker front sway bar will cause you to overpower the front tires sooner and cause understeer. However, if your car was not utilizing every ounce of available grip the front axle was able to give before, or if the smaller sway bar was allowing to front suspension to move outside of its ideal geometry, the new sway bar could be allowing the front axle to work more effectively. This would make the front axle grip better in turns and transitions. If the front is gripping better than it was before and the rear can't keep up with new found front grip you'll end up with an oversteering Miata. Fun, but not fast on the autox course.

If this is the case, removing the rear sway bar will only increase the amount of oversteer.

After adjusting preload, I'd try playing with air pressure. If you can't dial it out that way I'd look at getting a matching rear bar.

[lagunamiata]

I've got a Jackson Racing rear bar sitting around... It's actually my dad's, but he may be willing to let it go. I'll check if you want.

I think I'm going to take my stock bar to the 24 hr event and try swapping my RB rear for the stock one, just to see what it feels like.

[storz]

^^ Yeah I might be interested, I am going to reset the end links tomorrow and try to remove any preload that they have right now. I'll try that out and see how it goes. I think whats happening is that I have more grip in the front now with the larger bar.

[stealthgtfour]

the grip is the same its just that the bar makes your steering inputs more effective causing the rear to step out in transitions. once the car takes a set(skidpad or long sweeper) what does it do? alignment settings?a good 77 pothole can give you some less than desirable toe settings.

[storz]

Alignment was just done a few months ago by Performance Chassis in Cary - I dont have the specs in front of me but its set up fairly aggressively.

[stealthgtfour]

miata's are loose as it is and too much toe out in the rear doesn't make it any better

[lagunamiata]

Ryan - My dad was over this weekend (we went to the SCR National at CMP) and he said sure to sell the bar... PM me if you're interested.

[faded92mx5]

I used to have Jackson Racing bars front and rear with RB endlinks. I don't remember the diameters, but the front was massive. After two events of basically drifting, I took the JR rear bar off and ran the stock one, and also tried two events without the rear bar. I felt the car was most neutral with the stock rear bar. At the moment, I have stock front and rear, but plan to get an RB tubular front bar soon - definitely felt better with an aftermarket front.

[lagunamiata]

I'm going to bring my stock rear bar to the 24. I've been running RB tubular front and solid rear. I'll swap the rear bar out after a few runs... certainly can't hurt!

[stealthgtfour]

loose is fast!