Doubling a sway bar? (Adventra)

[routier1642]

SUMMARY: Can I reduce body roll by doubling the front sway bar?

Since I raised the suspension on my VZ Adventra LX6, using Kings Springs, I have had one problem: in a tight corner, the outer front wheel dips down really noticeably. This would be body roll, except that the rear doesn't dip as much, possibly due to the stiffer rear setup with the auto-levelling suspension.

If it goes down far enough, the ESP (stability program) thinks I'm about the skid, kicks in and brakes the front outer wheel. At first I thought this was OK - the ESP is preventing me skidding. But I tested it on the same corners at the same speed, same degree of dip, ESP turned OFF, and there's no skid, nothing like it, even if I go a little faster. So the ESP is going off prematurely. It's not dangerous; if anything, the opposite; but it is annoying.

I came up with 2 solutions:

1) change the sensitivity of the ESP by moving the yaw sensor backwards; this will decrease front yaw readings and make the ESP go off less often. The disadvantage is that the real effects are really unknown, and would be until I'm in a situation where I need the ESP!

2) decrease the amount of body roll by increasing the effectiveness of the sway bar. I've read articles on how to shorten it by drilling new mounting holes further from the end of the bar, but I'm not sure the VZ bar will accommodate this.
Then I read this article AutoSpeed - Sway Bar Shenanigans

The author clamps a SECOND sway bar to the first, increasing anti-sway effectiveness if not 100%, then by at least some amount.

So my questions are:

1) Has anyone else experienced this problem?
2) Has anyone else tried doubling or altering an Adventra sway bar?
3) Opinions?

 

[VK SL 3800]

Sounds like you need a stiffer spring, a sway bar will help but they can only do so much. Fit an aftermarket heavy duty sway bar and see how it performs.

Body roll is always going to be an inherent trait when you raise any vehicle so it might just be what it is.

 

[try_again]

Do you still have over-size tyres on it? If so they may be the cause of your woes.

 

[routier1642]

Do you still have over-size tyres on it? If so they may be the cause of your woes.

Yes, they add about 10mm to the height on top of the raised springs 30mm or so.

 

[greenacc]

Quality aftermarket sway bar, preferrably adjustable.
What spring did you use, stiffer or standard rate?

 

[routier1642]

Quality aftermarket sway bar, preferrably adjustable.
What spring did you use, stiffer or standard rate?

Easier said than done. It's an Adventra. The front sway bar is unique to accommodate the AWD.
Maybe a rear sway bar would be the same shape as for a VZ Commodore, but I think it's heavier.
Someone else suggested I could get one from an Avalanche, but good luck with that, :-\
In any case, I'm on a budget. I shudder to think what an Avalanche sway bar would cost.

Re: the springs. They are standard VZ Kings Springs (raised). I don't know the spring rate, though it is supposed to be variable with compression. They do seem a little soft for a heavy 2t Adventra. Not much I can do about that, or is there?

 

[greenacc]

So is the spring you used listed as the part to use for an Adventra ? If not then that will be your problem, too soft and will always handle like a jellyfish no matter what you do.
Maybe you would be better of using a V8 VZ spring as that would be stiffer than the V6 spring.
What about an Avalanche sway bar from a wrecker, can't cost too much ??

 

[routier1642]

So is the spring you used listed as the part to use for an Adventra ? If not then that will be your problem, too soft and will always handle like a jellyfish no matter what you do.
Maybe you would be better of using a V8 VZ spring as that would be stiffer than the V6 spring.
What about an Avalanche sway bar from a wrecker, can't cost too much ??

They are the correct springs:

HOLDEN ADVENTRA VYII VZ 10/2003 - 2006 - Fit your Vehicle - King Springs Automotive Aftermarket Springs

They don't specify V6 versus V8.

Avalanches were like hen's teeth, but I might have to start looking....

 

[try_again]

Put the correct size tyres back on and see if the problem goes away.

 

[routier1642]

Will a regular VZ rear sway bar fit an Adventra?