Snap Oversteer?

[nwilson44]

Okay, so I finished my suspension, at least for the time being, a couple months ago, but im just now getting to push it a little bit. my chassis had about 175,000 miles on it so I needed to change stuff. Here is what I did...

I bought the Bilstein Shocks/struts, energy suspension bushings (all the way around), new LS1 ratio steering rack, Moog tie rod ends, aftermarket rear anti roll bar, front shock tower brace. Might be forgetting some stuff, but that's most of it. Oh!, and I am running 275-40-ZR17's all the way around.

My rear end is a non posi 3.42:1, automatic.

Slow corners(35 MPH and below) are no problem, and the rear doesn't roll, at all. The front does slightly, but only because I haven't put the aftermarket front anti roll bar on it yet.

Fast corners (60 MPH and up) are no problem. The car takes a second to "set" itself and it just goes around awesomely. No drama, and can keep the pedal Floored the whole time and gain speed, the car stays neutral, and planted.


Medium speed corners (40-60 MPH)- this is where my problem comes in. The car turns in okay, but then understeers. Shortly afterward it snap oversteers (weird because I dont have a posi). I cant ride the drift through the corner either, it wont hold the drift. It either gains grip back and snaps back, or it totally does a 180.



Any ideas or help you guys can offer? I am happy with the low and high speed cornering behavior, just not the in between speed corner. I might be unhappy with the high speed if the car had enough power to make it loose traction in 3rd gear. However any advice is helpful.

[nwilson44]

Re: Snap Oversteer?

Any one know what size this is? I uploaded the pic I took of the aftermarket anti roll bar compared to the stock one. These are rear units.

[Ibanezz]

If those are both rear sway bars, that thing looks massive. Like a drag bar. Who did you buy them from? How did you even buy them and not know what size they were? You need the size to buy correctly sized bushings and end links. Also, the front sway makes the most difference so put that one.

[SlasherVRGR]

Yeah thats probly 23+ sized man.. way to big.
And a lot of people take the rear sway bar off for dragging I believe..

To big of a rear bar can definitely cause hairy handling situations, especially if it isn't flexing as much as the front. It would cause wonky telemetry and be fairly unpredictable sometimea

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[SlasherVRGR]

Upon further analysis I guess f-body guys don't remove them for drag racing but you get the idea :P

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[Ibanezz]

Upon further analysis I guess f-body guys don't remove them for drag racing but you get the idea :P

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Some fbody drag cars remove the front sway bar. It takes off a good bit of weight from the front end, and it really only helps turns so that's not needed on a straight line.

However, for the rear, they get a drag bar, which is very stiff. That helps transfer power equally to the ground, and helps keep it in a straight line. You don't want to remove the rear for any purpose.


But at the OP, the rear you bought may be too stiff, especially with the stock front sway bar you have on still. I upgraded to the SS/ws6 bars which are 32/19 and I love it. A guy I know had this set up and didn't like the way his rear reacted so he swapped to a 17mm rear. Its all about how your car feels. A lot of people get sway bars from Strano, which are 35/22 I believe. That's what the v8's upgrade as well. Yours honestly looks like 25mm which is drag status, won't know unless you have a part number on it to compare, or a micrometer to measure. But regardless you need appropriate sized bushings and end links to connect the sway bar to the car.

[FirebirdGT]

Re: Snap Oversteer?

Sway bar size and spring rate MUST be matched.

I have 351lb front springs with a 19mm rear bar. Had a 21mm and the car would oversteer.

Rear springs are 80/137lb progressive with a 35mm front bar.

GM did a 32/21mm bar setup for one year (93) only and went to 32/19.

Car runs on rails!

.

[nwilson44]

Re: Snap Oversteer?

Okay so first I need to see what size this is? The end links came with the kit, and the bushings were poly bushings. The rear control arm and panhard bar have poly bushings too. I will do some research into the size of my anti roll bar but I really like how I get like 0 body roll from the back:)

[CFreed11]

Re: Snap Oversteer?

Your handling will change quite a bit once you install the front sway bar... Your handling issues might be eliminated once you do that. The larger rear sway bar paired with a stock front one might just be upsetting the car in the turns.

[nwilson44]

Re: Snap Oversteer?

Your handling will change quite a bit once you install the front sway bar... Your handling issues might be eliminated once you do that. The larger rear sway bar paired with a stock front one might just be upsetting the car in the turns.

It would make it snap oversteer? Okay I will replace that front one and see what happens. It only does this in second gear power on situations. first gear situations dont upset it.

[nwilson44]

Re: Snap Oversteer?

I've found that the rear Sway bar is either 7/8 Inch or 1 inch (22-25.4mm)

[Ibanezz]

22 is a good rear sway bar matched with a 35 front. But if its a 25 that's too big

[nwilson44]

Re: Snap Oversteer?

Im not sure but its pretty big. So, basically guys, if I change my front sway bar, then that should get rid of this snap oversteer?

[FirebirdGT]

Re: Snap Oversteer?

22 is a good rear sway bar matched with a 35 front. But if its a 25 that's too big

That's just plain wrong.

Sway bars are matched to springs - not the other sway bar.

.

[FirebirdGT]

Re: Snap Oversteer?

Im not sure but its pretty big. So, basically guys, if I change my front sway bar, then that should get rid of this snap oversteer?

You have 257lb springs in front with a 17mm rear bar.

If running stock V6 springs a 22 is WAY TOO big unless you want to put a 500lb springs on the front.

.