Effects of a rear sway bar? Is a front lower member brace necessary?

[Revenant]

I have a Hyundai Matrix and I want to have her body roll and understeer reduced. I chanced upon this webpage that sells a rear sway bar and a front lower member brace.

If I have the rear sway bar installed, how will it affect road articulation, ie, will it take away some of the "independece" from the IRS? Secondly, if I have the rear sway bar installed, will a front lower member brace be necessary at all or will it be overkill, ie, overstiffen the ride or will it just be another expensive accesory in that it will not have any effect at all?

[speed unlimited]

Its really depend on where you will use the car . If you will use it in circuit track it is better . If daily driven and city driving i prefer a strut bar first if you dont have on your car.

[redorange]

The sway bar/anti-roll bar will help lessen the roll if you car doesn't have one already and if it does you can get a larger diameter bar to improve body roll. The brace is to lessen body/chassis flex at the front of the vehicle and will not improve the body roll.

[niky]

+1.

The rear anti-roll bar will lessen wheel articulation over single wheel bumps... but over humps, it's not a big deal.

[Revenant]

The brace is to lessen body/chassis flex at the front of the vehicle and will not improve the body roll.

Would it make a difference in terms of ride comfort or stiffness?

[redorange]

Unless you plan on racing the car the brace would be over kill since with the traffic in the Metro you don't go fast enough to feel some of it's benefits. Now if you just want less flex on your chassis and have a stiffer car then you can get it. The ride wouldn't change because it doesn't mount to the suspension of the car but the chassis. It's like adding a roll cage to the car, it makes it stiffer by virtue of the tubing connecting certain points of the car but it doesn't really change the ride. Even the anti-roll bar really doesn't do much to the suspension until you turn where it is meant to minimize the roll of the car. Yes it does affect some articulation but an IRS car doesn't really have all that much articulation, for some really deep pot holes you may lose some articulation but not enough for you to notice.

If you are trying to lessen understeer play with your tire pressure first before spending money. Lower the front and increase the rear pressure to minimize the understeer. Then go with the anti-roll bar, try to have a stiffer bar in the rear than the front if you want to minimize the problem. Keep in mind that most street cars are made to have understeer because most drivers don't know how to handle oversteer.

[niky]

Stiffer front is more understeer... stiffer rear is less.

Without other modifications, it shouldn't turn the Matrix into an oversteering monster... so it's relatively harmless... and a good upgrade.

[aejhayl17]

try hooking it up with wider tires.imho

[redorange]

Wider tires will not help body roll and can make the understeer worst.

[niky]

Yup. If you have a stock suspension, wider and/or stickier tires will sometimes exacerbate body roll.

[aejhayl17]

sorry sorry... i mean low profile-wider tires. reduce flexing of the tires at cornering. gets? it decrease the "sway" of the car almost(kahit papano)? hehehe lutang ako ngayon

[redorange]

He is also concerned about comfort and ride stiffness and a lower profile tire can degrade the ride comfort specially in pot hole heavy roads like Metro Manila. The wider tires will also make the understeer worst so it won't solve his problem. Go with the sway/anti-roll bar to get less understeer without degrading the ride comfort of your Matrix.

The brace and the strut bar mentioned in the second post will just stiffen your chassis and not help with what you are trying to accomplish. Play with the suggestions Niky and I gave and see how much changes.