If one corner of the car is shocked stiff, then as that corner desires to move in compression, more load will be retained by that corner as well as the opposite diagonal corner of the car during the compression cycle only. This not only insures consistent and proper spring rate, but also longer life (more cycles). It should help your 60' times by letting the rear squat more at the line before the suspension loads up. We felt that more standardized rating would be helpful to everyone involved. "There are two or three basic setups which are really simple, compared to bar car setups. Pivot bushings are bushings that were designed to remove the bind between the chassis and the spring. 4-Link The track radius used to determine stagger matters the most where the car will be accelerating. Running dampening shocks not only will tighten the car on entry, but will also prolong the life of the spring. The stiff LF spring setup does not work well on tracks banked over 10 degrees. The disadvantages of banding clips with rubber linings is that the rubber will absorb grease and brake fluids leading to deterioration of the components. Always use Grade 5 washers and deep well nuts. This will produce a lock-up or binding effect and the car will perform erratically and unpredictably. dQ#A$70 Q,6D|B@1" hKF? I don't get too many reports of continual, repeated wins and successes. In the case of an unbalanced setup causing a tight condition, the rear of the car wants to roll more so than the front. Of the many components that can be changed on a race car chassis, the coil spring change brings about one of the most adverse effects on a chassis. To determine the effective angle of a shackle, pull a string from the center of the front eye to the center of the rear eye of the spring, and then a line from the rear eye through the shackle pivot point. Several top-level teams have found that this movement actually causes the car to handle inconsistently. SHADOW RACING PRODUCTS973.684.7270www.shadowracing.com. When they are working together, the car is well on the way to a balanced state. We have continually pressed these issues because of the extreme importance they have. On a metric four-link car, the four control arms determine the rear moment center height too. We can raise the Panhard bar to raise the rear roll center, which will cause the rear suspension to want to roll less. Squared end leaves produce high stress points in each leaf leading to premature failure of the leaf. Landrum Springas well as many top-level teams have found this to be counterproductive when setting up a car and compiling consistent results. with r/r toe out the r/r wants to go to the wall you have to back steer and this makes it harder to get under a car coming off the corner.You always want to check the rear axle alignment because if you crash and have to put a new axle under it and the new one is toed different you could waste 2 or 3 weeks getting the car back right.I've checked a lot of housing,the winters quickchanges are good out of the box ,but the junkyard and 5 on 5 floaters are all over the place .I have found over years of racing that if my r/r has 1/16 to 1/8 toe in and the car is still loose I need to look at the springs,weight shocks etc.. Furthermore,Landrum Springis recognized as the only company in the racing industry worldwide doing so. It is this sliding scale situation that determines the stiffness of your front end. The driveshaft doesn't know which view these angles are resulting from, just that they are equal and opposite. When the shock travels, the divider between the shocks moves up the shock body. On some tracks, with cars using Detroit Locker rear differentials, the accelerating portion radius will be larger than the mid-turn radius. The driveshaft alignment is critical from the standpoint of mechanical efficiency. Note:To get the desired front end height (ride height), it may be necessary to modify the springs. Springs with banding type clips (see Figure 1) with rubber insulation produce inconsistent spring rates due to the fact of various durometer hardnesses and the deterioration of rubber compounds. Adding or removing as little as 50 pounds can also make a difference. You may not be able to find a 16-inch 100 rate spring, so this provides more spring length to use. Slinging the car into the corner or spinning out puts an extreme amount of lateral force on the springs which in turn, causes premature failure. Use a long (60 should be adequate) straight edge as a datum line. The rearend needs to be aligned at 90 degrees to the centerline of the chassis and/or to a line through the center of the right-side tire contact patches. The shape of the racetrack can affect how the car is balanced when exiting the turns. Moving the pull-bar or just the third link to the left increases the loading on the LR tire during acceleration. The less angle the better. In disciplines like dirt and asphalt circle track racing, suspension setups often require a highly specialized approach in order to maximize stability and grip, and that's led manufacturers to develop a number of different ways to approach common issues. Then a 2,000# spring could be anywhere between 1,900 to 2,100#. Bite Off The Corners As each season comes along, our knowledge of what we need and desire grows. For example, ARCA and other type stock-car chassis whose accuracy of pit stop changes are a necessity. This can enhance the life of the leaf spring because the shock will be absorbing some of the braking forces. Coil springs are the most common used spring in most all motor-sports today. When the car is not balanced, the neutral handling does not stay with the car for very long. Parabolic Single Leaf Consists of one main leaf with a tapered thickness. 11, 2022 at 1:54 PM PST. Cars that don't turn well are very likely to have poor MC designs. It doesnt solve the problem of multiple heat runs it simply tries to hide the fact. Most top shock technicians will be able to help you select the proper shock rates to go along with your particular setup related to your type of racetrack. If the LR shock has too much rebound, then that tire will lose a lot of load and not be able to provide traction. Once the setup has been balanced and the shocks are decided upon, we need to evaluate the turn-entry characteristics and the fact that brake bias is a very important influence at this segment of the track. Decrease the Pre-Load on the Front Stabilizer Bar. Measuring the arch from the floor up to the main leaf is referred to as table arch.LANDRUM SPRINGdoes not recommend using this method to accurately measure spring arch. Changing to a smaller sway bar increases the front roll angle, but not very much. For the Big Bar, Soft Spring setups, teams often introduce Pro-dive into the left front suspension to encourage rapid dive on entry to get the left front down quickly. When the car is jacked up during a pit stop for a tire change, the suspension may become completely unloaded leaving the coil spring to rotate in the spring bucket. This can make the car very loose and we need to adjust the suspension components so that it will not steer in this manner. by 72firechicken Tue Jun 21, 2011 1:34 pm, Post We have been softening those setups over the years, but never intended to go to coil bind or bump rubbers. Initial camber settings must be revised when changing from conventional to BBSS setups. This simple task will increase the life of the leaf spring dramatically. These types are desirable where stock lower control arms are used. It must show a consistent gain in performance and a logical ideology to the bulk of race teams. First, we needed to look at the previous setup to see what went wrong. The reasons are easy. We are at a crossroads at this point in time with setup technology in asphalt racing. This prevents undesirable chassis and rear end movement, thus creating favorable synergy between the chassis, springs and rear end. Another way to gain bite that we have described in the past involves the use of a spring-loaded pull-bar that allows a certain amount of rear end rotation. This puts undue stress on the leaf springs. This is not the same amount at all positions of the spring, and is different for the spring as installed. The new spring is tagged 2,200#; on the other hand, the unknown rate is 2,310#. In situations where the exit portion of the track provides less traction and/or the corner is more flat, we might need to develop more rear traction upon acceleration. Remember that drag is an important aspect of aero design. As a result, not every spring will come out exact. In addition, the choice of this material will allow a manufacture to wind the spring out of smaller wire to incorporate a larger pitch, which will inadvertently allow more travel and produce a lighter weight spring. Theinboard mounting positionof the springs play an important role as well. Leaf springs perform the following tasks: Due to all the loads leaf springs are under, it is one of the most stressed components on the race car. Another problem occurs with inconsistent resin mix which will cause the leaf to splinter and break. The engine vibration and the contact of the new wheel being installed on the hub face generally causes enough instability to cause the spring to shift in the pocket. We run a monoleaf on the right and a stacked leaf on the left. Therefore, less stagger should be used so that both rear wheels are turning the same rpm off the corner to avoid wheelspin. A 1 1/2-inch top view misalignment with a 44-inch driveshaft results in nearly 2 degrees of angle at both the tranny and the pinion shafts. The true arch of a leaf spring is derived from the measurement between the main leaf the leaf containing the bushings, and the datum line (the line that intersects the center of the front and rear bushings). It is the purchasers responsibility to order the correct products through their personal racing experience. Example the leaf will be 2 1/2 wide throughout its length, and .323 in thickness throughout its entire length. Complete kit includes a pedal with a built-in return spring and throttle stop, universal firewall bell crank. In fact, it is more important to get the mounting angles correct than selecting the proper spring rate.No matter what spring you put on the car it may not perform properly if the angles are misaligned.To counteract the effect of incorrect mounting angles, you may have to install erratic spring rates, shock rates, wheel off sets, unsuitable ride heights, and/or undesirable tire stagger, each of which will cause unpredictable handling characteristics. This is an effect that increases the amount of toe-out in our race cars when we turn the steering wheel. A common misconception is that arch affects free spring rate, which it does not. Meaning that as the spring is compressing it is gaining rate. $119.99; 119 - Reward points. Landrum Performance Springs offers a range of aftermarket suspension springs used primarily in Circle Track Racing, Drag Racing, Off-Road Racing & Powersports markets. Address: 304 5th Creek Road, Statesville, NC, US, 28625; Free Phone: 1-704-871-0817; Post by RCJ Wed Jun 22, 2011 9:05 am, Post ASPHALT MODIFIED (Standard 3 Point and 4-Link Cars) 2006 Set-Up and Technical Guide. PDF TUNING THE CAR WITH SPRINGS - teamgrt.com Because the front tires generate more traction with a greater angle of attack, the driver is actually putting more traction into the front end. Increase the Split in the Panhard Bar Heights. The leaf spring will last longer because the shock will assist in absorbing the dampening forces. Landrum designed their front drag racing coil springs to store energy for instant, maximum weight transfer for launching. 6. It's no wonder. The message I get from those who have worked this trend for a sufficient number of years is one of the following two types: 1) a continuing and constant search for balance in the car and a loss of success on the track, or 2) a returning to the more conventional setups because they have experienced number 1 above. The reason I say that with confidence, is because I have gone up against more aero efficient cars with setups and body configurations that were aero-deficient and still out ran them. In the next issue of CT, we will delve into the setup problems for a dirt car. Also, check out QA1's YouTube channel for tech, product and company videos! Adjust Cross Weight as changes are made to keep the car neutral. Pitch is the distance between the wires on any given coil-spring. The setup we choose needs to be arranged so that the dynamics are balanced between the front and the rear suspensions. And as for you Modified and Stocker class teams, don't even think about it. 200 x 200 = 40,000 (Top Spring Rate X Bottom Spring Rate)200 + 200 = 400 (Top Spring Rate + Bottom Spring Rate)40,000 400 = 100 Rate, Click here to download as PDF Chevrolet. Check Tire temps, if LF is coolest (unbalanced setup): Decrease front springs, maybe even use reverse split (LF stiffer). Brake Bias Usually, improved mid-turn handling offers the most gain in overall performance, and that is why we start there. The following is a list of things that can make the car not want to turn or make the car loose. Balance the Front and Rear stiffness. Bushing choice will also affect spring life, and more importantly, spring performance. Urethane and aluminum bushings tend to transfer more energy and loads directly to the spring. The idea is to steer the car using different height holes for the rear control arm mounts. Stagger affects handling in each phase of the corner if the car has a locked rear differential. If the pitch is too close together then the spring may not have as much travel resulting in coil binding. Antidive helps prevent sudden nose dive on entry by mechanically resisting the downward motion of the suspension using the rotational forces created through braking. STANDARDIZED TESTING:Landrum Springuses the same rating system that many of the race teams that participate in the premier race divisions (CUP, ARCA, and IRL uses.) Furthermore, there will tend to be less stress on the spring and spring related because the pressure will be equally distributed throughout the spring and chassis. This can cause an undesirable change in spring rate and wheel base settings. When this is severe, the front end will push and no adjustment to other setup parameters will seem to help the situation. The reason less shackle angle, more preload on each leaf, and a taller resistance line. How to raise the cross weight in an iRacing asphalt setup. The car is loose right at mid-turn and off the corner. Furthermore, the crew made unnecessary changes, wasted valuable time, resulting in wear and tear on the engine, tires and other components. by 72firechicken Wed Jun 22, 2011 3:46 pm, Post If the wheel is turned farther at speed, the car is tight. Here is a recent quote from a reader who has found that perfect balance. We will cover the different aspects of leaf springs from free rate to installed rate, applications, hook up points and other performance enhancing factors. Some springs may need .780 or .810 wire so as to not to be high stressed. If there is, try to adjust the brake bias to eliminate the adverse condition. Installing a torque device combined with these types of suspensions will cause the wrap-up rate to be excessive. Here is an explanation of balance related to the dynamics of the race car. hb```9,"o@(Yf8 rijYd`Pu9s9`*fm3 fxEGG;`(1Aja;ZYm @PfdPhv`
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To fix this, reduce the rebound rate in the LR shock and/or stiffen the compression rate on the right-front shock. The amount of resistance is directly related to the degree of side view angle we put in our control arms and the amount of brake force used. Sliding the MC left and to the inside of the turn makes the suspension softer. As the front brakes are applied, the caliper grabs the rotor and the motion of the wheel/rotor tries to rotate the spindle. Ackermann is easily checked by using a laser system or strings. Knowing that every spring has its own characteristics, Landrum Spring, engraves the exact rate of each and everyGOLD COILto 1/10#. However, the negative effects of these bushings greatly outweigh their intended purpose. The rear tire sizes must be different in order to compensate for the turn radius so that the rpm in both rear wheels will be equal. Examine the spring immediately upon receiving. Rear Suspension - Circle Track Supply, Inc. When running balanced setups that work the left-front tire, we must eliminate most of the Ackermann. That troubles me. The number one reason a car will be tight and not want to turn is because the front end is not designed properly. The chassis was as good or better at the end than it was at the beginning.". Never over torque the stationary end (front eye) bolts, as it will prevent the suspension from moving freely. Here are what we consider to be the 10 most important areas of chassis setup with No. Although the camber change is quick and the wheel returns to normal camber settings a short time later, once the push starts, it is hard to stop it without slowing down. Place the straight edge on the spring so that it intersects the front and rear bushing. A trend must prove itself in order to stand the test of time. However, tie down shocks are becoming less and less desirable. Lower the Rear Panhard Bar on both sides. asphalt metric street stock setup asphalt metric street stock setup on March 30, 2023 on March 30, 2023 Circle Track - Asphalt Suspension | Allstar Performance Speed up and do a few hot laps, and again note the position of the steering wheel. $259.99. At the end of the day, the springs where rated. Decrease RR Trailing Arm length by 1/8 inch. We mostly use the sway bar to tune for traction off the corners. 8. Circle Track - Asphalt Chassis | Allstar Performance 0
x 13tall x 200# coil spring) may be engraved 201.8. This is the true arch of the spring. The stacked spring concept is being used on the left rear, right front and sometimes on the right rear to fine tune the race car. by RCJ Wed Jun 22, 2011 8:36 pm, Post EMERGENCY HELP CELL# 973.951.5135. Furthermore, the spring will absorb all the weight transfer, and not plant the tire securely on the track. Through interviewing various teams, we found that current spring suppliers were using many various methods of rating coil springs. The effect will be a lack of forward and side bite under acceleration. No matter which stiffness you decide to go with, the most important aspect of setup is balance, and you achieve that balance with the correct combination of springs, moment centers, sway bars, and load distribution. This induces less rear steer when the car squats on exit. These theoretical rates are just that, Theoretical. In testing conventional setups over a five-year period, it was discovered that most tires want no change in camber relative to the racetrack surface as the car dives and rolls. Manufactured from only the best high-tensile chrome silicon material. Once it reaches a predetermined point, the divider hits the stop and the top spring is no longer able to compress. Clipshave a profound effect on spring rates. The influence of the location of the front MC can be compared to a sliding scale. endstream
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<. All the driver knows is that the car is loose. Good luck. With setups that use a very stiff right rear spring, the angle of the right trailing arm will need to be less than when using a conventional softer spring because that corner will move less. Roughly 8-10 degrees of third link angle is sufficient to promote antisquat and not hurt your corner entry. Too light of a spring rate will also cause the rear end to lose an excessive amount of pinion angle under acceleration, leading to a loss of forward bite. by 72firechicken Sun Jun 19, 2011 5:44 pm, Post Since the braking forces are in the opposite direction, there is a serious resistant force created which helps prevent the front suspension from moving in compression too quickly while braking. When the LR tire is the coolest on the car, the rear spring split may be too much. Suspension Set-up There are two common suspension set-ups found on typical rear wheel drive vehicles at the track: 4-Link and Leaf Spring. Mid-turn handling problems are caused by a car that is either tight or loose. A typical problem is a spring that has excessive arch in the center. Decrease the Split on the Rear Panhard Bar Heights. Different bushing diameters and unleveled floors will lead to inaccurate measurements. Some teams refuse to run sufficient stagger to match the radius and banking of the racetrack. Increase the Rear Brake Bias. With the car set up correctly, it is just a matter of experience and a little racing luck that brings that first win. This is important due to the fact that some springs may be in various warehouses, dealers and chassis shops for up to two three years before reaching the race team. This system uses two springs on tip of each other in series. e;
So, with some of the information we have learned over those years applied, here is a modernized version of that article. Instant Center Adjustment - JOES Racing Products LIT-722 C7 Z06 Corvette Heat Exchanger 80294NDP. The rate of a spring is the change of load per unit of deflection (N/mm). Knowing this,Landrum Springas elected to rate, dyno, print (numerical as well as graphical data), engrave each springs serial# and rate. CTS SUPER DUTY LEAF SPRING ROLLER STYLE SLIDER-CHEVY OR CHRYSLER STYLE. So, again this year as in past years, we will present what is admittedly the formula for success related more for the conventional and what we call soft conventional setups mainly because these are the ones that produce more consistency and do win races. Anything over 3 tends to be excessive and decreases forward bite due to the fact that the torque wrap up or forward thrust resistance of the rear end increases, therefore not allowing any wrap up or torque dampening to occur. Due to the fact of the popularity of the leaf spring system, we felt racers may want to understand more about how the suspension actually works. The reason is because it is very easy to change the component as well as check the rate, unlike leaf springs and some total hydraulic shock suspensions. One should use the same free height, but change rates. Leaf Springs | Get Started Racing Free of . The wine-and-cheese crowd refers to these as oversteer and understeer. The tire temperatures still supported his feel. Antidive and antisquat are mechanical influences that can help our transitional phases of entry and exit. Do not seek aero downforce at the expense of aero drag increase. The actual total spring change instead of 200#s is 410#, over 100% more or twice the spring change desired. Surface Open to the public Mark as open if it is closed due to COVID-19 but open usually. I would try it. Leaf-Spring Systems - The leaf-spring rear suspension system locates the rear-end fore and aft, as well as laterally using the leafs. So, there is a limit to how much you can get away with and still have a decent corner entry. Cars with a lower CG should have a MC that ends up farther to the left side of the scale than would cars with a higher CG. Leaf Spring Conversion Chart. Although these changes will alter the height of the car, the spring rates will be unaffected as long as you stay within the guidelines. Drag Racing Front Spring Tec. But if your running a stock 4 or 5 leaf set up. Furthermore, with the incorporation of the coil-over spring/shock type suspension, the coil spring and shock ratio is close together and operates as one unit. How To Master Traction in Your Leaf Spring Car Part I %PDF-1.5
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However, it does affect the installed rate. That simple test has helped many teams quickly determine the status of their setups so they will quickly know which direction to go when tuning the mid-turn handling. Afcos web site has leaf spring installation tips.I ran camaros and what I did was raise the front eye 3/4 and lower the rear 3/4''.A flatter spring has less rear steer and should have more anti squat.2'' lowering blocks is the most I ran,make some heavy duty ones yourself .I broke several that I bought.Check the toe out in the rear end houseing, heat and quench the tubes to get 1/8 toe in.Then string the car to get the r/r toed in. Increase the Caster. The steering system in your car must be evaluated and any negative characteristics must be eliminated. The difference is you also use a stop mechanism lock out nut that stops the travel of one of the springs at some point during shock travel to where the car is then riding on only one spring. By purchasing springs that are already accurately rated, you will not have to pay your engineer ($$), team manager ($$), or crew chief ($$) to rate springs that you have purchased. 3. Let say that a chassis engineered wanted to increase the right front spring rate by only 200#. The very first step in the process of preparing for the new season is to consider all performance-related items and how they worked last season. As the rear end rotates on acceleration, the left wheel moves rearward more so than the right wheel, creating a slight amount of rear steer to the left. Increase the Rear Tire Stagger. Each end has its own moment arm length and resistance to roll as well as other factors. A very soft spring would need more compression rate and less rebound rate, whereas a stiff spring would need a lot of rebound rate and much less compression rate. Measure the angle derived from the two lines. Each suspension system desires to do its own thing when lateral forces are introduced from the car going through the turns. by racerx1622 Mon Aug 29, 2011 2:12 am, Post They report running about 0.75 inch and complain that the car is tight off the corners. A-Arm length and mounting height have a dramatic effect on Instant Center Location. Decrease LR Shock rebound and/or increase RF Shock compresion. (2.) The right-side tire contact patches will also need to be inline with the right front tire pointed straight ahead. A particular car at each racetrack will require a certain amount of rear stagger. With excess Ackermann designed into our cars, on purpose or not, we can gain a lot of toe-out, which causes our front tires to work against each other. So in some cases, using chrome vanadium for higher rated springs is a better choose than chrome silicon. A dampening shock may be used to tighten the car on entry. Alignment issues are defined as: A. rearend alignment, B. contact patch alignment, C. driveshaft to pinion/transmission alignment, and D. engine alignment. This malady is more common than most racers know. These desires are directly influenced by the spring stiffness, location, and spring split, the sprung weight the system has to support, along with the moment center locations and other settings. We race a '76 Pontiac LeMans with the 4 link rear. Our springs are available in a wide range of sizes and rates. To accomplish a forged flat end, the spring material has to be heated more than once. Here, we will examine the problems associated with a car that handles poorly and some logical steps to take to find the most balanced setup. In addition, teams would not have to purchase expensive testing equipment. Circle Track Setup: Springs 101 - iRacing.com Those were salvaged out of the old car and were perfectly fine. This is very "old school" but when applied with a balanced setup, very effective. The advantage of this style is that the spring is lighter than the multi-leaf. Put the tires on it you are going to race then rotate the tire and scribe a line all the way around the tire.Be as accurate as possible.After you have scribed both tires measure 4'' off the ground the distance between the scribed lines on the front side of the rear end then measure the distance between the lines on the back side off the rear end.You might get a number from the front like 72 .5'' , the number from the back might be 72.375 this would be 1/8 total toe out.This does not tell you if one side has 1/8 toe out and the other has 0 toe.Putting the axle in the car measureing from the center line ,string it etc..will tell the toe of each wheel.You might think this crazy but I've looked down the side of enough race cars I can see an 1/8 toe with my eyes. It consists of a center bolt that properly aligns the leaves and clips to resist its individual leaves from twisting and shifting. Measure from the main leaf to the datum line. SPRINGS WITH HIDDEN COST $$:Simply put it, buyingGOLD COILSmay save most any race team money. right rear leaf spring with matching arches. 9. It is important to design the spring to its environment as well as its intended use. In most cases the static deflection differs from the actual deflection of the spring between zero and static load, due to influences of spring camber and shackle effect. Multi-leaf springs used for racing should incorporate leaves that are diamond trimmed on each end, not leaves that are tapered on the ends. Leaf Spring Technical Information. Excess stagger should never be used as a crutch to help make the car turn if it is tight. DESIGN: Most coil spring failure is directly related to the design of the spring. What really makes the setup work is precise shackle angles, the angle that you mount the shocks, and keeping that right rear free-moving."
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