Anti squat, anti dive and anti lift geometry which will be referred to as anti geometry when discussing them as a whole is a form of geometry at the front and rear wheels that alters and controls the amount that a car will compress the springs due to acceleration, deceleration or braking conditions. The vehicle suspension geometry showed excessive anti squat and. Antidive front suspension can be used to limit this characteristic. I am in the process of tubing my front end and fabricating front suspension points but i am curious about building in antidive geometry. Holiday promotion performance trends software there are a lot of good software brands available to help optimize your suspension geometry, work out different suspension setups, improve your steering geometry, etc. This height difference and the driving force will create a torque that tries to push the rear suspension out. Antidive suspension geometry with inboard or outboard brakes antilift suspension geometry with inboard or outboard brakes antisquat suspension geometry with independent suspension or solid axle antiroll bar antisway bar stiffness. This can be achieved by tilting the upper front control arm a arm so the rear. While it sounds like a simple inverse, its actually quite different as it has little to do with pedaling force, and much more to do with braking forces and the subsequent shift of your weight. Last time, we talked about antisquat, which is a frames rear suspension designs resistance to compression under acceleration and pedaling forces. At some point you will want to enter your own suspension geometry data or even just just view the current model in more detail. Suspension geometry part 1 camber, toe, caster, kpi. Antidive is a suspension parameter that affects the amount of suspension deflection when the brakes are applied. A definition of anti dive as it pertains to motorsports suspensions.
Autoware autoware inc front suspension geometry software. Antisquat antidive triangular control arm aluminum rear ends which w126. Injuries or damages resulting from the 22 oct 2011 wingeo3 suspension geometry program analysis. The rotational point of the swing arm is above the point where the motorcycle drives itself the ground. Anti dive is a suspension parameter that affects the amount of suspension deflection when the brakes are applied.
I upgraded and the antilift values exported to excel are different. For analysing suspension geometry we use susprog 3d ie roll centres, camber curves, scrub etc. There are many thick textbooks, expensive software, and hundredpage internet forums out there on the subject of 4link geometry and it is very. I would like to find the stock control arm pick up attachment points for the c5. This is a simple representation of my cars suspension geometry. We believe you cant fix or improve something including racecars unless you know how it works first. They can be thought of as the counterparts for braking and acceleration as roll center height is to cornering. The vehicle suspension geometry showed excessive antisquat and very low antidive properties. Design of a suspension system and determining suspension. Suspension key performance indicators kpis can be used to understand how a suspension system will perform under different driving conditions, e. The suspension analyzer does a complete 3d suspension analysis, including bump steer, ackerman, caster gain, anti dive, tire scrub, camber gain and much more. Bike fit purchasing a bike of an inappropriate style, model, size, or geometry. Anti squat the anti squat of a motorcycle is caused by the swing arm suspension system. Imca modified front end questions part one the dirt forum.
We have 5 programs that work with anti dive when conducting suspension simulation. Welder series although the mustang ii is not the best layout for competition, it is a tried and true geometry for thousands of street rods and hundreds of thousands of highway miles. How to decide if i need prodive or antidive suspension. Suspension setup springs and antiroll bars sway bars.
It is a point of conversation between true car designersengineers whether it is good to have or not. I didnt design any into my suspension for a couple of. It just came to my attention that us 560sec and 560sel only had the aluminum rear control arms up to 1987 while it seems the euro models had them through the end of the chassis production based on my research in the epc. Conversely antidive is used to describe how much a chassis nose dives under braking. Motorcycle anti squat motorcycle geometry software suspact. Complete graphs and reports are included, and several new. This challenge checks your ability to modify the geometry and run the simulation. Antisquat antisquat is a concept used to determine how much the rear of a chassis will squat under acceleration as a result of the rear geometry. Analyse suspension geometry for weight transfer issues eg calculating springs and antiroll bars well use the weight transfer worksheet. This camber thrust can work with you or against you in the corners depending on your front end alignment and suspension geometry. Suspension calculations include coil and leaf springs, antiroll bars, animated suspension geometry analysis with roll center and instant center for dual aarm and strut suspensions. Anti dive suspension geometry with inboard or outboard brakes anti lift suspension geometry with inboard or outboard brakes anti squat suspension geometry with independent suspension or solid axle anti roll bar anti sway bar stiffness.
The same logic goes for anti squat as anti dive and some. As the car rolls the front suspension tightens up and makes the car think it is sprung stiffer. Now i know one might argue that theoretically it is prov. Antidive suspension geometry explained antidive suspensions are used to reduce body dive by altering the front suspension so that the forces resulting from braking pass through the control arms and suspension linkage rather than through the coilovers or struts. Many manufacturers have all of the parts needed spindles, brakes, springs, sway bars, etc. One of the most common questions we get about suspension setup and tuning is how 4link geometry affects.
Now you can get all the racewise chassis school material in an easytouse software program for your home computer. Later with technology the braking improved with discs and also the telescopic and other kinds of suspension systems came up that allowed better. In addition to being accurate, i find performance trends software to be. I have heard that the spacers that go between the front suspension mount and the aarm mounts affect the antidive geometry. These are shown as the dotted lines in the picture below. It happens because of change in inertia, in a similar fashion that pushes us into the seats when we accelerate. Design of three and four link suspensions for off road use. The main reason for the difference is due to the different design goals between front and rear suspension. Make your own ifs based on mustang ii geometry article by. I am interested in using c5 control arms, front and rear, on a project car. Finding your center finding your front and rear roll center. Racewise provides the technical understanding of suspension and tire performance that racers must have in order to make no guesswork decisions. This challenge checks your understanding of side view geometry parameters like antisquat and antidive.
Stop guessing and start winning learn the facts of front suspension geometry with this informative cdrom computer software. In this project you will use both theoritical calculations and simulations to achieve the required target levels for suspension anti characteristics. This screen also lets you calculate anti dive, and important handling parameter. I wouldnt go so far as to put ridiculous amount of anti dive in the car. Racewise provides the technical understanding of suspension and tire performance that racers must have in order to make no guesswork decisions regarding chassis setup, handling analysis and adjustments. The suspension travel analysis allows you to see what happens to the suspension during travel. The suspension system comprises antisquat and anti dive element. Suspension systems with anti dive values under 100% will cause the front suspension to compress under breaking, often called nose dive. Specifically interested in antidive angle for the front but could use any info. 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.
Personally i see squats and dives as extreme fine tuning for the driving experience read comfort and i dont really see it relevant in baja sae. Simulation of effect of suspension geometry on rollover. Using a small amount of antidive lets you run softer springs in the front. Antidive suspension geometry explained engineering. By using characteristics of the rear suspension design and the layout of a typical chain drive, however, we can give the motorcycle antisquat geometry tendencies that offset the compression from load transfer, in turn improving handling performance on corner exits as the motorcycle accelerates. These systems are commonly found on vehicles used for the sport of rock crawling, or for recreational use on unmaintained roads. Antidive is a suspension parameter that affects the amount of suspension. Antidive suspension geometry with inboard or outboard brakes antilift suspension geometry with inboard or outboard brakes antisquat suspension geometry with independent suspension or solid axle antiroll bar antisway bar stiffness calculation for tubular or solid bars coil spring stiffness calculation leaf spring stiffness. These parameters were considerably improved by simple modifications in suspension hard points, tuned such that requisite proportions of antisquat and antidive forces are generated with a little compromise in handling. Suspension optimization of student formula race car. The second option is to purchase suspension software. Getting started with lotus suspension analysis tutorial 1 getting started 18 as the suspension point is moved the suspension geometry graphs will be continuously updated and the position of the suspension roll centre will move on the 3d display. On all circle track cars, stock cars to modifieds, when a wheel is cambered, the tire generates a lateral force known as camber thrust.
Under acceleration, a low anti dive geometry will cause the front end to lift and the suspension to extend which also shifts weight to the rear of the vehicle. For example, with inboard brakes and halfshaft driven rear wheels, the suspension linkages do not, but with outboard brakes and a swingaxle driveline, they do. The program is compatible with windows xp, vista, win 7, win 8, or win 10 which means it is easy to use and you will be able to print the results on most any printer, usually in color if your printer supports it. Suspension calculations and suspension simulations. Pressing the edit button immediately switches to edit mode listing more details about the dimensions of the model and allowing you to. For the very common double a arm suspension, antidive is designed into the suspension based on the angle of the a arm mounting points when viewed from the side.
Antidive suspensions are used to reduce body dive by altering the front suspension so that the forces resulting from braking pass through the control arms and suspension linkage rather than. The method of determining the antidive or antisquat depends on whether the suspension linkages react to the torque of braking and accelerating. Roll centre characteristics, antidive and antisquat. If you balance the instant centers, and consider all of the compromises that come with race car set ups, you can make subtle adjustments by manipulating the timing of suspension compression corner entry and suspension roll corner middle. By reducing body dive, the front wheel geometry will remain more consistent, and. 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. Suspension key performance indicators kpi suspension. My understanding of antidive in the front suspension is its capability to offset any nose dive during braking conditions. I do have the stock settings for caster and camber. Front suspension antidive geometry pelican parts forums.
Antisquat anditdive triangular control arm aluminum rear. Antisquat, antidive and antilift geometry which will be referred to as antigeometry when discussing them as a whole is a form of geometry at the front and rear wheels that alters and controls the amount that a car will compress the springs due to acceleration, deceleration or braking conditions. If the intersection point of the extension lines for the mounting points is located above the neutral line, there is more than. As we compress the suspension to analyse the antisquat throughout the full range of travel, we must also consider what the front suspension is doing. Antidive suspensions are used to reduce body dive by altering the front suspension so that the forces resulting from braking pass through the. Susprog3d is the premier kinematic suspension design and analysis tool. Suspension design software faq suspension by design.
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