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The million dollar rear sway bar question- remove it?

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Old Mar 6, 2004 | 11:49 AM
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From: Clarksburg/Bridgeport WV- North Central Appalachia
The million dollar rear sway bar question- remove it?

I've got my rx-7 in the garage on stands, the rear sway bar removed (I think it's a suspensions technique brand- non-adjustable. Same on the front). I need to change all four end link bushings.
I've been reading back and forth on removing the bar all together..What do you all think? Is oversteer that much more pronounced without the bar or is it no problemo- predictable?
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Old Mar 6, 2004 | 12:32 PM
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Actually oversteer is greater with the bar. Removing the bar decreases rear roll stiffness, thus increasing the rear bias of the front/rear traction distribution. The million dollar answer is to try it both ways and decide what you prefer.
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Old Mar 6, 2004 | 12:33 PM
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Removing the sway bar as I have done on my 84 se track car only slightly betters the oversteer situation. In my experience at the track with my car, spec 7 suspension, falken azenis 195 60 14, the only difference I noticed was a little better stability when braking into a corner. Removing the bar actually does nothing to correct the bushing binding which occurs in the upper control arm bushings as well as the watts linkage. Rx7Carl has written an article on this (look in the archive)which thoroughly explains the ideas I mentioned earlier. Bottom line, keep the bar. Unless you plan to track the car sometime, in which case I strongly recommend Rx7Carls mods, leave it on.
If you have any questions, email me.
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Old Mar 6, 2004 | 12:39 PM
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Originally posted by evita
Removing the sway bar as I have done on my 84 se track car only slightly betters the oversteer situation. In my experience at the track with my car, spec 7 suspension, falken azenis 195 60 14, the only difference I noticed was a little better stability when braking into a corner. Removing the bar actually does nothing to correct the bushing binding which occurs in the upper control arm bushings as well as the watts linkage. Rx7Carl has written an article on this (look in the archive)which thoroughly explains the ideas I mentioned earlier. Bottom line, keep the bar. Unless you plan to track the car sometime, in which case I strongly recommend Rx7Carls mods, leave it on.
If you have any questions, email me.
So it sounds like, in your experience, the handling is better (slightly) without the bar. Why do you recommend leaving it on?

Keep in mind that the effect of removing/changing the rear bar will have a lot to do with the spring rate set up on the individual car and the bar that's on the front. The stiffer the spings in the rear suspension, the less of an effect there will be by removing or changing the bar.
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Old Mar 6, 2004 | 01:27 PM
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Originally posted by purple82
Actually oversteer is greater with the bar. Removing the bar decreases rear roll stiffness, thus increasing the rear bias of the front/rear traction distribution. The million dollar answer is to try it both ways and decide what you prefer.


try it with out.. then try it on.. and see what you like better. every one drives differently. some like it off, some like it on. its all opinion
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Old Mar 6, 2004 | 03:47 PM
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Well- I just went for a spirited drive on some backroads..Not being a suspension guru, I can say by seat of the pants that it handles fine w/out the rear sway bar..Maybe more predictable. However- The roads were wet, so I did not push it by any means.
The springs on the car are tokico, with tokico blue shocks/struts. They are stiff- REALLY stiff. Fronts are progressive @194 and the rears are 111. By comparison:

Stock- Front 100 / Rear 85
RB- Front 145 / Rear 110
ST- Front 85/120 / Rear 80
Eibach-Front 171 / Rear 100

My springs are kidney busters. It usually feels like the NOSE of the car corners tighter than the rear - sorta 'pulling' me through a turn. I can't feel the rear end at all (with the large swaybar). Years ago when I owned an 86 MR2, I could easily predict the cornering and feel the rear end 'pushing' through a turn. Sorry if this sounds a little shade-tree, but suspension is by far my weakest link in automotive understanding.
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Old Mar 6, 2004 | 03:58 PM
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you think those are stiff. im running 350/150 i need to wear a cup.
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Old Mar 6, 2004 | 04:06 PM
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From: Clarksburg/Bridgeport WV- North Central Appalachia
OUCH!!
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Old Mar 6, 2004 | 04:21 PM
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Well instead of removing the rear sway bar, consider going with a front strut brace, and a larger front sway bar.

These FB's in stock form are pretty over-steered cars. To make it more even, some people take that rear sway bar off to get it closer to understeer range, with a little more predictable max cornering. This is the wrong direction to go IMO. Leave it on, and upgrade the front to larger sway bar and even a strut brace will do the same to tone down the oversteer and increase the max stiffness and provide better cornering.
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Old Mar 6, 2004 | 05:38 PM
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Originally posted by WackyRotary
Well instead of removing the rear sway bar, consider going with a front strut brace, and a larger front sway bar.
All of us that track our cars and have been trying to control oversteer have already installed the largest front swaybar available -- it doesn't help much. A strut tower bar does virtually nothing. I have one of those, too and can testify. The strut tower bar looks neat, but in reality is probably more of an NVH benefit than an outright handling aid. (If you have more questions about that aspect, I'll be happy to tell you all about it.)

Here are some other things I've done to try to help the situation:

1) Removed rear swaybar
2) Spherical bearing Watts Link conversion (Mazda Competition)
3) Dual ball bearing conversion at the Watts Link pivot (home made)
4) Spherical bearing lower trailing link conversion (Ground Control)
5) Stiffer springs all around (Eibach)

As an earlier post indicated, the binding of the rear suspension causes the roll gradient in the rear to skyrocket. Once the car rolls past a certain point, it's as if somebody threw a huge swaybar on the rear. What's especially bad about this is the suddenness of the handling transition. Push the car at 7/10ths and it doesn't feel so bad, but take it past 8/10ths and look out!

Removing the rear swaybar will depend on your personal tastes. If you retain it, the transition to severe oversteer will be more gradual. Without it, the transition will occur at higher cornering loads. Either way, the whole situation is slow. If I could get the rear end of my car to stick better in the high speed sweepers, I could turn much better lap times.

A tri-link rear setup is next.
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