Aug 21, 2015 this week i did some work to determine the roll center height of the car and decided on switching from rod end bearings to spherical bearings to improve the. Suspension geometry an overview sciencedirect topics. The mustangs rear suspension design forces the upper control arms to perform two jobs at once. Lister storm lmp designer reveals his trade secrets for suspension design. One external weight jacking device allowed per wheel. Around 1990, a racing friend contacted me to analyze the suspension geometry on a car he had acquired. Classic industries offers a wide selection of 1974 chevrolet camaro parts, including 1974 chevrolet camaro interior parts and soft trim, 1974 chevrolet camaro exterior sheet metal, 1974 chevrolet camaro moldings, 1974 chevrolet camaro emblems, 1974 chevrolet camaro weatherstrip and unique accessories, to nearly every nut and bolt needed for installation.
Computer program for 3d double aarm wishbone suspension analysis. Classic industries offers a wide selection of 1976 pontiac firebird parts, including 1976 pontiac firebird interior parts and soft trim, 1976 pontiac firebird exterior sheet metal, 1976 pontiac firebird moldings, 1976 pontiac firebird emblems, 1976 pontiac firebird weatherstrip and unique accessories, to nearly every nut and bolt needed for installation. The performance trends suspension analysis software illustrates the extreme movement of the roll center on a strut car. Together these components create a superior handling suspension system with multiple geometry and setting adjustments for further tuning and improvement. Susprog3d is a complete 3d software package for the design, setup, evaluation and visualization of race and road car suspension systems now with support for 30 different suspension types. Development of the unbalanced engineering decoupled torque. Torque arm suspension systems chevy high performance.
Geometry optimization of double wishbone suspension. A relatively high roll centre is obtained which will be roughly at the upper torque arm height. To calculate the instant center of a torque arm suspension you draw a vertical line through the torque arm front mount. Featuring a huge selection of racewise suspension geometry software in stock and ready to ship today. The instant center is the point where the two lines intersect. If this is your first visit, be sure to check out the faq by clicking the link above. Design of suspension system for formula student race car. They control the sidetoside position of the axle housing, while.
The anti squat of a motorcycle is caused by the swing arm suspension system. Lower lateral link, upper reversed aarm, twin trailing links rear a variation on the above. At some point you will want to enter your own suspension geometry data or even just just view the current model in more detail. Zooming out makes the diagram smaller and allows you to see the ackermann steering imaginary line intersection points compared with the position of the rear axle. Design of a rear suspension configuration for a live. Technical help with rear suspension model a hot rod the h. Upper lateral link, lower parallel links, twin trailing link rear. Some performance suspensions out there are based on mustang ii suspension, a suspension that was developed for a lightweight compact car using 1970s technology, and at a time when performance handling wasnt a part of the vocabulary of most american cars. With that said, what would happen if polaris kept the same front torque arm geometry and combined it with a coupled rear arm. The result is a considerably distorted semielliptic spring and body to axle misalignment. Racewise suspension geometry software parts speedway motors.
The figure 4, 5, 6 shows the suspension geometry in lotus suspension analysis. Generally, reducing the amount of antilift geometry improves traction across the front axle, and therefore reduces understeer so often found on most road cars. This document, the associated hardware, software, drawings, and other material set. Changing your mustangs stock suspension to this superior design gives your mustang more rear grip and all the benefits thereof, including. I did a lot of drag racing this year first year with the 8 and at ls fest i did the auto x and 3s challenge and it was a total blast and i want to do more. Finite element analysis software was used to create a fabricated 9 fab9.
The torque arms tapered design is achieved by combining lasercut panels with. The cad model of the trailing arm is prepared by the optimum values of the suspension geometry and is shown in the figures 24. Live axle torque arm 2 trailing links and torque arm slider watts linkage. Suspension geometry characteristics of a live axle are as follows. Design of formula sae suspension theory in practice. Because internet explorers maximum url length is shorter than other browsers, your project cannot be saved properly in this browser. You could easily have a height adjustable mount where the front of the torque arm connects to the chassis. If ever you see the explosion it means that a clash or breakage would occur. Due to the geometry of the suspension, the spring rate of the suspension spring may be very different than the spring rate at the wheel due to angles and lever arm lengths of the various components. Unique in their design, the suspensions virtually eliminate the inherent change in geometry and possible traction issues. Ideally any other locating arms should be parallel to the ground with the car at ride height and if those arms are short compared to the length of the torque arm there should be some means for the torque arm to move back and forward at the forward mount. The classis 60s sports and racing car rear suspension.
Automatically optimize the location of certain components for roll center. Finding your center finding your front and rear roll center. The torque arm does need to be rigid at the rear end if you want it to act as a torque arm. Design, analysis and fabrication of rear suspension system for an all terrain vehicle aniketthosar abstractall terrain vehicle atv is defined by ansi as a vehicle that travels on low pressure tires, which is used to handle any kind of terrain it faces. There are dozens of variations of suspension types used on race and passenger vehicles. As torque is applied to the rear wheels, the arm now fixed to the housing rotates to push upward at the chassis mount while simultaneously pushing downward onto the wheels. This system reduces wheel hop to improve traction for.
The torque arm suspension system is simple but very effective. Trailing arm, upper and lower lateral links rear as used on the pre 84 chevrolet corvette with the drive shaft acting as upper lateral link and a leaf spring and bmw e36 with bespoke lateral links and coil springs trailing arm, upper and lower lateral links, toe control link rear as used on the honda integra type r. Susprog3d suspension by design is a complete software package enabling the. Jun 30, 2015 a skillfully engineered system with multiple geometry and setting adjustments for tuning and refinement, chassisworks torque arm glink suspension directly replaces the oem leaf springs and shocks for significant performance increases in cornering ability, throttle response, and braking stability. Dont assume that the person who originally built the car decades ago with wrecking yard parts knew what he was doing. Instead of a radius arm with a fixed mount on the axle, it uses an upper and lower link on each side with pivots on both ends. For any given suspension stiffness at the wheel, calculations are required to find the stiffness of the suspension spring. The torque arm can be mounted below or above if there is room the axle.
Chassisworks used the latest analysis software to develop a superior to steel spindle, that is much more rigid and lighter weight. Shop the industrys largest selection of torque arms at. Suspension geometry part 1 camber, toe, caster, kpi. Apr 24, 2012 bmr suspension has recently introduced a complete line of torque arm suspension systems for classic chevys. The cortex torque arm changes the antisquat and antilift geometry of the rear suspension. It goes well beyond our simpler roll center calculator to include steering inputs, bump steer toe change, ackerman, caster, anti dive and much more. When a mustang is lowered from the factory ride height the. Most of the good torque arms are adjustable, and theres no reason to buy an aftermarket torque arm thats not adjustable unless you dont plan on drag racing. This paper presents the procedure of design and analysis both kinematic and dynamic of the front double aarm pushrod suspension system for a formula student race car. To take full advantage of the improved rear suspension geometry of the mm torquearm suspension system, the rear spring rate must be changed. Much like the oe suspension used in third and fourthgeneration camaros, these setups. Our new extreme chassis handling abilities are optimized for both street and track situations.
Lower control arm mounting holes, may be moved on rear end housing only. All of this affects the angle of the torque arm and your instant center and the amount of antisquat. Downward force creates additional traction that is equally distributed to each tire regardless of current body roll or suspension travel state. Chassisworks protouring torquearm system can be adapted to fit just about any muscle car, street rod, truck, or custom car project. On my 14 i used bmr lowering springs, stock 3way controlled dampers, bmr lcas and the griggs torque arm and watts link.
The suspension calculator aims to help people who are building race cars perform suspension related calculations. Helpful suspension geometry calculators barnes 4wd. Has anybody made a torque arm rear setup i have a 96 standard cab short bed with a all aluminium 5. Customfit modern suspension technology and toptier manufacturing quality are no longer exclusive to the small group of popular and pricey mainstream vehicle models. Design of three and four link suspensions for off road use. Depending on the type of racing for race cars, the road surface and evolution of the vehicles, the suspension is designed to accommodate multiple requirements. Get free shipping on racewise suspension geometry software at speedway motors. Chris alstons chassisworks, inc chassisworks torque. I did do the sa bump steer rod ends and sway bar links but all else is stock. In this example, we would call that the front leaf spring eye. Leaving the upper control arms in place would cause massive suspension binding because you would have both a 4link and a 3link suspension on the same car, with both systems trying to cause their own particular rear suspension motion. This height difference and the driving force will create a torque that tries to push the rear suspension out. Susprog3d is the premier kinematic suspension design and analysis tool.
Computesreports all critical front suspension factors like moment arm length and shockspring travel. Youd like to remove the front mounting point from the transmission, and to place it where the gload brace is, or to tie it laterally to your subframe connectors. Once the geometry has been set up, the paper will discuss how to measure the. As a base point, in order to calculate the standard suspension geometry accurately, i used chris gibb. For windows 7, 8 and 10 with opengl see the faq for more details faq for more. This could be the chassis hitting the ground, a control arm hitting a wheel or a control arm being stretched to the point it would break. Subframe gconnectors and center support create the torque arm chassis mount and are required for operation. It is based on chapter 7 of the book chassis engineering by herb adams isbn 1557880557. Jun 16, 2017 if you dont have a thorough knowledge of suspension geometry design, buy yourself a kit from someone who does. Pressing the edit button immediately switches to edit mode listing more details about the dimensions of the model and allowing you to alter the model by dragging any of the tether points. Camaros and firebirds from 1982 to 2002 used this type of suspension and performed great. This screen shot shows a double a arm system, but the software also works with strut suspensions.
Jul 29, 2015 antisquat suspensions are used to reduce body squat by altering the rear suspension so that the forces resulting from accelerating pass through the control arms and suspension linkage rather than. When a mustang is lowered from the factory ride height the rear suspension geometry is compromised reducing rear grip under acceleration. Allows steer, roll and bump or rebound suspension movements. This approach is now well established and will be discussed. The roll center, as its name implies, is the center of rotation for a suspension system. Depending on the type of suspension, the roll center can be an actual pivot point or a virtual point in space and they dont necessarily lie along the center line of. The calculations vary from motion ratios, to spring stiffness, to wheel loads. Reduced rear wheel hop under braking the primary means to reduce wheel hop under braking is to reduce the amount of rear antilift geometry. The ackermann option shows imaginary lines to help you envision ackermann steering geometry. Make adjustments to the bar lengths, either in inches, or turns of a particular thread pitch, and program shows how everything will change. A variation on the radius arm suspension is the parallel fourlink, shown in the figure above. Motorcycle anti squat motorcycle geometry software. Torque arm suspensions have been stock on many cars for a long time, from the 1930s to the current day.
Aftermarket manufacturers make kits that retrofit an existing radius arm suspension to a parallel fourlink design and use coil springs and a track bar to center the axle. Torque tube with trailing arm and transverse watt linkage live axle rear. This is a term relating to four link trailing arm setups, but is rarely. The steering arm ball joint is not needed for the basic geometry calculations, but. This is a basic get you going tutorial, using the registered susprog3d software. The resulting increase in suspension geometry control is substantial. You can use this as a gauge to work out the extents of the suspension travel. Length of the lower control arm has been determined to be 460mm, with a spread of 355mm. The 4link wizard helps you determine the ic choices available with your fourlink bars so you can home in on the sweet spot and reap the benefits of a fourlink suspension. Vsusp no longer supports any version of internet explorer. Torque arm suspension systems chevy high performance magazine. The software also provides series of graphs such as camber vs roll angle, camber vs bump, toe vs bump etc. White smoke with the inclination you can define the instantaneous center of the suspension, and then the height of the instantaneous center relative to the height of the center of gravity determines how much antisquat or antidive you have. Speedtech performance usa torque arm rear suspensions dramatically improve performance handling and everyday drive quality of your leaf spring car.
Pressing the edit button immediately switches to edit mode listing more details about the dimensions of the model and allowing you to. Typical rear suspension screen, here analyzing an angled 4 link rear suspension and driveshaft movement and u joint angles. There are 10 key factors to be considered when designing a suspension system, whether its for a single seater or sports prototype, and part of the skill of the designer lies in reconciling the conflicts between them. The bindfree mm torquearm increases rear grip so much that the rear spring rate needs to be raised in order to increase the rear roll resistance. Speedtech performance usa torque arm rear suspensions 10330. Using the latest technology in computer modeling and simulation software all aspects of the suspension geometry were calculated and tested until the best possible numbers were achieved. Top view of the trailing arm suspension the assembled static geometry model is imported in the. Click on measurements, then adjust bars for the adjust bars screen shown in middle of screen. Rear suspension upper control arm or torque arm mounting holes, may be moved on frame only. All these subtypes and more essentially try to keep the wheels planted on the ground, as free of oscillations and wheel hop as possible, and as straight and true with the direction of the vehicle as possible.
This will allow for rear toe adjustment and will also transmit most of the rear suspension load into the central part of the chassis, where it is strongest. Live axle torque arm 2 trailing links and torque arm slider panhard rod. The spinoff from this design is a return to a conventional tunnel and the benefits and appeal that offers. Polaris engineering thought the same and the result is the procc suspension which lives inside the track. Lower lateral link, upper reversed a arm, twin trailing links rear a variation on the above.
Side view of the inclined trailing arm suspension fig. The suspension analyzer does a complete 3d suspension analysis, including bump steer, ackerman, caster gain, anti dive, tire scrub, camber gain and much more. There is a roll center for the front suspension and rear suspension. Axle wind up is the tendency for the axle to twist or wind up due to the torque. The rotational point of the swing arm is above the point where the motorcycle drives itself the ground. Then you draw a line from the center of the tire contact patch through the lower control arm pivot. A torque arm suspension is a variation of a 3link suspension. Design, analysis and fabrication of rear suspension system. It consists of a long suspension member called a torque arm that is mounted between the differential and the chassis or transmission, a pair of lower control arms, and a panhard rod or watts linkage to laterally control the axle. Antidive refers to the amount of builtin antidive in the front suspension of any car relies on braking torque.
Negative toe, or toe out, is the front of the wheel pointing. Speedtech extreme subframes mustang ii suspension and corvette spindle based geometry are things of the past. The trails option displays the paths of the tie rod steering arm intersection point. Camber matters optimizing track performance for strut. May 30, 2016 a roll center is what determines the datum point around which all other suspension geometry moves. The lower control arm will also incorporate the toe link on the front of the control arm. Speedtech extreme subframes speedtech performance usa.