Airbag
In some applications, racers will install a specially designedbag inside the rear spring(s). This bag can be inflated to increase thespring rate of that particular spring. In most cases, increasing therate of the right-side rear spring can help limit roll rotation onlaunch, which helps the vehicle drive straight. A drag race-style, rearantiroll bar, however, is the preferred method of limiting andcontrolling roll rotation.
AntiRoll Bar (rear)
Many chassis builders and aftermarket suspensionsuppliers offer rear antiroll bar kits to enhance dragstrip performance.Antiroll bars (also called sway bars) are actually torsion springs, andwhen applied to the rear suspension they can limit roll rota-tion (seenas twisting) and enhance vehicle stability as well. The drag-style rearantiroll bar features two bushings or bearings that are mounted betweenthe chassis rails at a location above the rear housing. A torsion bar isthen located between the bushings or bearings, and the bar is connectedwith links that drop down and attach to the rearend housing. When launchis viewed from the back of the car, you'd see that the body rolls to theright and the rear housing actually rolls to the left. The antiroll bar,which is connected between the body and the rear, works to resist thisopposite loading and keep the rear and body from twisting apart. Theresult is equal loading to both sides of the rear housing, which alsomeans more equal traction to each tire.
AntiRoll Bar (front)
Most vehicles will be equipped from the factorywith a front antiroll bar. This bar works under the same principle asthe rear bar, but it is connected to the chassis and to the front A-armsvia end links. Since the front antiroll bar ties the lower A-arms to thechassis, it has a tendency to limit front-end lift on launch. That'sbecause the antiroll bar prevents full extension of the lower A-arms.For the purpose of drag racing, therefore, it is beneficial to removethe front antiroll bar as this will result in more rapid and increasedpitch rotation of the front end.
Bearings/Bushings
At points where moving parts meet or touch there willbe a certain amount of resistance or friction. It is necessary toinstall a material softer than those touching each other to reduce thisfriction. To accomplish this, bearings or bushings are installed. Thesecan be found between suspension links, inside the wheels, and inside theengine. Shown above are polyurethane bushings used on various suspensioncomponents. These generally replace softer rubber bushings, which tendto flex or distort more than polyurethane.
Coilover shocks/struts
Anyshock or strut that is fitted directly with a coil spring is consideredto be a coil- over shock. Most coilovers are more compact and lighter inweight than stand-alone spring and shock, or strut combinations. Thisallows them to fit neatly between wide rear tires commonly found in dragracing. It also allows racers to change springs more easily.
Control Arms
Late-model Mustangs from 1979 to 2004 (excluding'99-present Cobras and Cobra Rs) utilize a four-link rear suspension,with two springs, four shocks, and a small antiroll bar that linksbetween the two lower arms. This system incorporates two upper and twolower control arms (also called trailing arms). The arms connect to therear housing and to the vehicle on the opposite end. Stock arms areformed from stamped steel and use rubber bushings at each end. The softrubber limits noise and vibration, but it is not optimum for racingapplications because rubber tends to deflect excessively. Theaftermarket produces quite a few variations of the upper and lowercontrol arms. Some are made from billet aluminum, some from round-tubealuminum, and others from boxed aluminum or steel.
Driveshaft Safety Loop
A driveshaft safety loop is a device made ofsteel that surrounds the driveshaft 360 degrees and is designed tocapture the driveshaft in the case of driveshaft or U-joint failure. TheNHRA and IHRA have specific requirements for size, type, and placementof the driveshaft safety loop.