Sway Bars 101
- Sway bars reduce your Mustang’s body roll while tackling corners
- Aftermarket sway bars are sometimes adjustable as well for further fine tuning
- Front sway bars link the struts together to keep your Mustang level in a corner
- Rear sway bars connect to the rear axles and help reduce understeer
- Too stiff of a bar will make driving on bumpy roads uncomfortable, much like how a stiffer suspension would be more jostling
Sway bars are a key component to making your Mustang handle well. Sometimes referred to as anti-roll bars, they are used to help control body roll when turning or making sharp maneuvers. Sway bars are a torsional spring, they work by tying both sides of the suspension together, forcing both struts to move in tandem. By forcing one side to raise or lower the same amount as its partner, you are able to reduce the amount of body roll. As a bar gets stiffer, the stronger the spring becomes, and the stronger spring will result it less body roll. Another benefit to upgrading sway bars is the ability to tune the understeer and oversteer effects for your car or preference.
Front Sway Bar
On a 2005-2014 Mustang, the front sway bar works by linking both the front struts together, and on a 79-04 Mustang the front bar works by connecting to the lower control arm. It is also attached to the frame of the vehicle, giving it a place to rotate. Since sway bars are torsional springs, installing a stiffer front sway bar will force the struts or lower control arms to raise and lower with each other at a very similar rate. As one side of the car drops down, the other side will rise because of the increased spring rate of the bar, keeping the body level. By increasing the stiffness of the front bar, you may also increase the amount of understeer that the vehicle experiences. This can be equalized by increasing the stiffness of the rear bar.
Rear Sway Bar
A rear sway bar is installed by bolting drop links to the chassis of the car, then bolting both ends of the sway bar to the rear axle. Since the rear axle on 79-14 Mustangs is a solid axle, you don’t need to worry about the wheels moving at different rates, but the stiffer bar will help keep the rear of the car from rolling. As one side of the car drops down, the bar will pull down on the other end link, preventing roll. If you are experiencing too much understeer on your Mustang, you can install a stiffer rear bar. The increased spring rate on the rear will help take some of the cornering load off the front car, allowing it to turn more sharply with less understeer.
Downsides to Larger Sway Bars
By adding more bar stiffness, you will increase the amount of jarring felt by uneven roads, since the bumps will be transferred more easily from one wheel to the other. This is not usually noticeable when running an adjustable bar on its lower settings, or by getting a more mild non-adjustable bar. When increasing bar stiffness too much, a vehicle may also lift a tire off the road. On a solid axle car like 79-14 Mustangs, the inside front tire would be prone to lifting when cornering, since it is being lifted up to match the level of the outside cornering tire. This is generally not an issue unless you are cornering very aggressively, with an incredibly stiff bar.
Should I Get Sway Bars for my Mustang?
If you are trying to make your Mustang into a corner carving monster, or just want a street toy with better balance and handling, sway bars are definitely a must. If you find the factory suspension to be sloppy and unresponsive, a set of sway bars when used with lowering springs and a good set of shocks and struts, will give you crisp and responsive car. If extra noise, vibration, or harshness are a big deal for you, get a set of good street/track bars. They will be mild enough that the jarring effects of stiffer sway bars will be very minimal, while the handling benefits will remain. If a little extra road feel isn’t a problem for you, then a set of stiffer bars, or the stiffer settings on an adjustable set of sway bars will be perfect for your Mustang!
Adjusting a Sway Bar and its Impact
Most aftermarket sway bars have three holes on the ends where the sway bar end links fasten to. The furthest adjustment hole away from the sway bar will cause the sway bar to rotate less than holes which sit closer inward to the sway bar. The furthest adjustment hole away from the sway bar will provide a softer or "looser" transition. The closest adjustment hole toward the sway bar will provide a stiffer or hard transition.
Soft Front Bar:
- Increases front traction of the car while decreasing the rear traction
- Increases the roll of the car
- Understeers the vehicle
Stiff Front Bar
- Decreases front traction of the car while increasing the rear traction
- Decreases the roll of the car
- Oversteers the vehicle
Soft Rear Bar
- Increases car roll
- Decreases front traction while increasing rear traction
Stiff Rear Bar
- Decreases car roll
- Increases front traction while decreasing rear traction
- Increases Steering sensitivity during high speed cornering
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