In a solar car the lower control arm mounts level to the axle and the upper control arm mounts at at point roughly level to the top of the wheel. The jig kept everything in place while the parts were being made. The paper will discuss chassis layout, and then lead into the specific process to be followed in order to establish optimal geometry for the unique functional requirements of the system. The double a arm independent suspension, also referred to as a wish bone or shortlong arm sla suspension is the preferred front suspension used in racing today. Probably best just to flare the car and run wheels with 8 or so inch backspace. Front suspension overview our initial concept suspension in solar cars is not designed to provide a smooth ride. In order to calculate the percentage amount of antilift that the front suspension geometry has, the.
Trailing arm suspension is mostly used for the rear suspension of the passenger cars. Autowares racing and performance tech site software for auto racing and high performance cars data acquisition systems new and used engineering services and live seminars on performance and racing technology all types of tech info on racecar engines, chassis and suspension setup for road. Geometry control means changing geometry parameters toe and camber during certain driving conditions. First up is the proper design of a control arm suspension.
This software is specifically designed with a userfriendly interface that makes the process of computer aided suspension design and analysis much faster and more convenient. C5 corvette suspension geometry i am interested in using c5 control arms, front and rear, on a project car. The wrx sedan has a wider track, and i believe its due to the. In part two we look at the more dynamic side of suspension movement. The core of performance no matter how you will drive, the suspension system is the backbone of your cars capabilities.
Control arm is made with oem quality bushings and top quality greasable ball joint. Software for auto racing and high performance cars data acquisition systems new and used engineering services and live seminars on performance and racing technology all types of tech info on racecar engines, chassis and suspension setup for road. Assuming you dont want to redo the suspension installation you can either raise the ride height to correct the suspension geometry. This keeps all you suspension geometry intact and working properly. Control arm lca used in the front suspension system, which is a sheet metal component. Stop guessing and start winning learn the facts of front suspension geometry with this informative cdrom computer software. Filip trojanek, founder, professional engineer compare suspension systems by application street track racecar competition proven, unmatched value unlike most. However, the bushings that serve as the pivot points for the control arms get a real work out, and over time, they wear out. The load acting on the control arm are dynamic in nature, buckling load analysis is essential. The suspension on a vehicle serves multiple purposes. Double wishbone suspension system it is popular as front suspension mostly used in rear wheel drive vehicles. A variation on the radius arm suspension is the parallel fourlink, shown in the figure above. By keeping these three points traveling on the same arc you. Camber matters optimizing track performance for strut.
Suspension geometry characteristics of a live axle are as follows 1. The upper control arm geometry will be finalized once the hub and spindle designs are complete. Remove the upper and lower control arm bolts at the frame end and save the factory hardware. Stock car suspension moment center technology hot rod. In most cars the upper and lower control arm will mount above and below the axle. Solid monoball control arm ends offer a more responsive suspension over the factory onepiece rubberinjected control arm also uses the same high strength steel alloy spherical bearing found in our control arm monoball kit. All of these were based on the original geometry to make sure that we would have no issues when cycling. Design, analysis and fabrication of rear suspension system. Opel aps has invented a suspension geometry control system and we would like to inform you about it. Design of three and four link suspensions for off road use.
Geometry angle changes are being performed in the range of 0. Specifically interested in antidive angle for the front but could use any info. After the instant centers are located you can now find the roll center. There are three sections in the roll and bump config. Suspension is designed such that it provides better handling and better comfort for an atv. In this study cad model was prepared using catia v5 software and finite element analysis. Soft suspensions waste energy by absorbing the motion of the car as it travels. Classic industries offers a wide selection of front suspension for your 1972 chevrolet truck. These drop brackets are engineered to work with aev 2. On each side of the car we have upper and lower control arms, in a double a arm suspension. Restores chassis performance application specific oe geometry ensures perfect fit and function. Unique design provides more gusseting over the motorsports arms for added strength and aesthetically appealing looks.
Lca is modeled in proe software for the given specification. Because internet explorers maximum url length is shorter than other browsers, your project cannot be saved properly in this browser. As far as the entire control arm goes, the wrx is different. Includes chassis dynamics, spring and shock theory, front and rear suspension geometry, real world racing aerodynamics, steering systems, racing chassis software and all you need to know to set you chassis. Classic industries offers 1972 chevrolet truck ball joints, 1972 chevrolet truck bushings, 1972 chevrolet truck control arms, 1972 chevrolet truck conversion kits, 1972 chevrolet truck front end rebuild kits, 1972 chevrolet truck spindles oe, 1972. Front and rear suspension analysis simulation software program. As well as shims, slugs and spacers for getting the right geometry out of the front end or even a new cross shaft to replace to one you bent. Racewise rwfront front suspension geometry software made by. Lister storm lmp designer reveals his trade secrets for suspension design. Front end geometry help needed new pics added 728 the. Daystar kt03008bk upper and lower front control arm bushing,black.
Anti squat, dive and lift geometry suspension secrets. Global west suspension brings modern handling to classic cars through its negative roll concept, which reengineers your front suspension geometry to better match modern lowprofile radial tires. It is important for the suspension to keep the road. Updated with nearly 60 percent new material on the latest racing technology, this book details how to design, build, and setup the chassis and suspension for road race and stock cars. Revolutionize your ride with products like delalum control arm bushingsthe raceproven bushings that perform like bearings, eliminating.
Vehicle travel and roll is simulated by dragging the image with the mouse, or with scroll bars. Yesterday your musclecar seemed to handle like a dream, but your stock suspension cant keep up with todays tires and engines. Basic suspension geometry lessons rod and custom magazine. Most come with moog problem solver ball joints and premium bushings preinstalled. I would like to find the stock control arm pick up attachment points for the c5. Vsusp no longer supports any version of internet explorer. This screen shot shows a double a arm system, but the software also works with strut suspensions. We delve into some of the key concepts and designs. More precisely, it is an angle between upper and lower steering axis pivot points when viewing from the side of the car. It provides a way to isolate the chassis and driver from the shocking jolts that the tires experience going over anything but a glasssmooth surface. It consists of two control arms aarms for each wheel. I am testing a single arm suspension controlled by the shock.
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. Kits are usually shipped the day after the order is received. Design and analysis of lower control arm international journal of. Macpherson strut lower control arm ball joint play and. Once the geometry has been set up, the paper will discuss how to measure the. Finding your center finding your front and rear roll center. Design, analysis of atype front lower suspension arm in. The performance trends suspension analysis software illustrates the extreme movement of the roll center on a strut car. Suspension systems must support both road holdinghandling and ride quality, which are at odds with each other. Control arm options using stock mounting points stock arms with flipped uppers and mcgaughy 16 drop spindles are a cheap and effective front setup as long as the wheel and tire combo isnt very large. Chassisworks used the latest analysis software to develop a superior to steel spindle, that is much more rigid and lighter weight. You can use this as a gauge to work out the extents of the suspension travel. Front view suspension geometry calculatorsimulator. To answer your question, the rear control arm bushings are the same, except for the forester and outback.
May 09, 2009 i would recommend herb adams book as a starter. These systems are commonly found on vehicles used for the sport of rock crawling, or for recreational use on unmaintained roads. Oct 01, 2007 cowlmounted steering boxes, however, should also be mentioned since the geometry can cause horrendous bumpsteer if there is a lot of suspension travel, though of course most rods have a minimum. The tuning of suspensions involves finding the right compromise. It is based on chapter 7 of the book chassis engineering by herb adams isbn 1557880557. Computer program for 3d double aarm wishbone suspension analysis. Upper control arm length inches lower control arm length. Rss tarmac series front lower control arms for 986 987.
I explain some of the pros and cons to moving around the pivot points and changing control arm. Control arm placed longitudinally along the driving direction and mounted on suspension sub frame or body on both the sides. Buy a 1981 chevrolet camaro control arm at discount prices. Cowlmounted steering boxes, however, should also be mentioned since the geometry can cause horrendous bumpsteer if there is a lot of suspension travel, though of course most rods have a. Each system is comprised of a fabricated torque arm, a pair of. 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.
The movement may be in the tierod ends or control arm bushing if you do the balljoint. For us, we had to create three jigs one for the spindle, one for the upper control arm, and one for the lower control arm. It is used at almost every level of racing the sprint car is one notable exception. The chassis outline blue lines can be dragged up and down and rolled from side to. Racewise rwfront front suspension geometry software. When viewed from the side, if the upper ball joint is behind toward the back of the car the lower ball joint, the car has positive caster. Moment center geometry software will help you determine the dynamic location for your mc. In bump and droop increments, set the maximum and minimum travel to 100. From the rf instant center you draw a line back to the rf contact patch center. The instant center is simply the point where the upper control arm pivot point and the lower control arm pivot point lines intersect.
The second line extends from the lower ball joint through the inner pivot on the lower control arm. A strut front suspension without an upper control arm uses an adjustable upper strut mount known as a camber plate to adjust camber and caster. The basics of suspension geometry, as well as a diagonally identical wheelbase, spring rates, and wheel offset, must be adhered to if you want your car to handle well. The resulting increase in suspension geometry control is substantial. This is a basic get you going tutorial, using the registered susprog3d software. The second option is to purchase suspension software. In this video i go over how i decided to go with the geometry for the front suspension on my baja. Suspension types tutorials downloads data files faq purchase here contact us basic suspension geometry. The amount of anti squat present is determined by a few factors such as the side view swing arm length and height, wheelbase and centre of gravity height.
The upper control arms ucas are stronger than the stock arms and are 100% bolton. In the case of a mcpherson strut suspension layout, the respective points are strut mount for the upper pivot and ball joint in the lower control arm as the lower pivot. Macpherson strut lower control arm ball joint play and suspension geometry. The resulting increase in suspension geometry control is. This is a simple representation of my cars suspension geometry. I havent read the other books by carrol smith or milliken yet, but i was able to design a set of front upper and lower control arms for a single seat buggy that me and 3 of my friends built and raced with 17 of travel. Length of the lower control arm has been determined to be 460mm, with a spread of 355mm. Pdf design optimization of a wishbone suspension of a.
Theory craft rear suspension geometry custom irs adaptation. Racewise provides the technical understanding of suspension and tire performance that racers must have in order to make no guesswork decisions. Calculate the instant center on your drag car suspension geometry. Suspension geometry an overview sciencedirect topics. Steering movements are achieved with tie rods positioned to reduce geometry change during suspension travel, also known as bump steer. This paper will cover the suspension geometry and its components, which include the control arm, uprights, spindles, hubs, and pullrods. Thickness of the control arm is varied in different steps to optimize it, so as a. Now you can get all the racewise chassis school material in an easytouse software program for your home computer. Classic industries offers 1967 chevrolet truck ball joints, 1967 chevrolet truck bushings, 1967 chevrolet truck control arms, 1967 chevrolet truck conversion kits, 1967 chevrolet truck front end rebuild kits, 1967 chevrolet truck spindles oe, 1967. Susprog3d suspension by design is a complete software package enabling the. If one wheel moves over a hump or dip in the road then the axle will tilt causing both wheels to become cambered. Uneven tire wear, suspension noise or misalignment, steering wheel vibrations are the main causes of the failure of the lower suspension arm.
Jan 29, 2018 suspension geometry part 1 camber, toe, caster, kpi, scrub radius sk8215. The paper covers simulation, modeling and analysis of suspension geometry. Instant centers are much easier to visualize than roll centers. Index terms all terrain vehicle, new improvised rear suspension, objectives, trailing arm with camber links, design, analysis and fabrication. One of the control arm bushings was not pressed into the control arm quite far enough. Instant center calculator for your drag car suspension. Wheel camber is zero irrespective if the vehicle is stationary or moving round a bend in the road.
Control arm is subjected to high torsional and bending stresses. 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. Around 1990, a racing friend contacted me to analyze the suspension geometry on a car he had acquired. I had to take extra time with a hydraulic press to correctly seat the bushing into the control arm so the assembly would line up and bolt in easily. Choose top quality brands dorman, hotchkis performance, mevotech. Each control arm is attached to the chassis at two points and attached at a single point to a steering knuckle. It joins the wheel hub to the vehicle frame allowing for a full range of motion while maintaining proper suspension alignment. Design of the geometry of double wishbone suspension system along with design of spring. The lower control arm will also incorporate the toe link on the front of the control arm. Optimumkinematics developed by optimumg engineers is a suspension and design analysis software. Suspension geometry part 1 camber, toe, caster, kpi, scrub.
Design optimization of a wishbone suspension of a passenger car. The chassis movement control allows you to raise and lower the chassis and also rotate the chassis by moving the mouse or your finger side to side. First, lets start by looking at the suspension movement and the tools available to make your life easier. On this episode of rock rods tech its trailing arm suspension explained by jake burkey. This could be the chassis hitting the ground, a control arm hitting a wheel or a. The double aarm independent suspension, also referred to as a wish bone or. The lower control arm supports the load of the vehicle and the upper arm maintains the position of the steering knuckle, allowing the steering system to turn the knuckles left or right. Symptoms of worn control arm bushings include suspension noise and clunking while cornering and the inability to hold an alignment. I know the upper control arm, has to be, or is shorter in length to benifit the upgrade. 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.
Through suspension travel the intersect point moves based on the length, angle and connection point of the upper aarm and the lower control arm. The geometry of chassis design and suspension movement dictate the handling characteristics of a car. Zach messaged me about making a thread on the front suspension kits available for the nbs trucks to talk about pros and cons to each kit. So i took his interest and decided to do a thread and also make instill some info on suspension geometry. Trailing arm suspension explained with jake burkey rock. The 2002 lawrence technological universities formula. Antisquat geometry is a function of the control arm geometry at the rear wheels. If ever you see the explosion it means that a clash or breakage would occur. This highlights the need to ensure that there is some adjustability built into either the rack or the steering arm ball joint mounting. If the ball joint fails, you have to buy a new upper control arm upper. Design of formula sae suspension theory in practice. Autoware autoware inc front suspension geometry software. We have gone from essentially a blank piece of paper, to a basic suspension geometry.
Sep 15, 2016 the jig kept everything in place while the parts were being made. Index terms all terrain vehicle, new improvised rear suspension, objectives, trailing arm with. Jun 30, 2018 on this episode of rock rods tech its trailing arm suspension explained by jake burkey. It provides a stable platform from which to control the vehicle. The bump steer is pretty good, but the roll centre control may need a bit of work. They have spacers built into the bushing mount that change the geometry of the suspension, similar to an alk. Go to display control and in the show section make sure that all items are turned off they are not ticked. Suspension is the system of tires, tire air, springs, shock absorbers and linkages that connects a vehicle to its wheels and allows relative motion between the two. Direct replacement control arms by moog are designed to solve steering and suspension problems in nothing flat. The geometry of the s550 rear suspension will not like narrowing. Jake will be teaching you all that there is to know about trailing arms and why you need trailing arms off. Your suspension system design and materials can make or break a cars success in motorsports.