Vintage/Classic/Historical Engine Tech, 3V Performance Engine & Valve train Development, Race Cars & Parts - For Sale or Wanted. After viewing the data sheets we found that the 375# tagged spring was actually a 387# and the 400# tagged spring was a 385#. A car can appear to be loose even though it is tight. Once it reaches a predetermined point, the divider hits the stop and the top spring is no longer able to compress. Setup Balance For instance, a J200 (5o.d. If a user was to lose their sheets then we should be able to pull the data up at a later date. Although they are the oldest, they seem to be the least understood. The length decreases, the width increases, the thickness increases, the number of leaves increases, Brinell hardness increases, utilizing a harder durometer bushing. on the right rear, you should not install a taller spring on the left rear with the same spring rate as the right rear. 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. e; If the same stiffly shocked corner is in rebound, less of the overall load will be retained by that corner, and its diagonal corner as well, during the rebound cycle only. Also, excessive torque of the shackle bolts will increase the installed rate. A particular car at each racetrack will require a certain amount of rear stagger. Shocks Leaf Spring Technical Information. EveryGOLD COILhas its own dyno sheets incorporated in its box when leaving our facility. Stacking Springs for 2.5 Coil-overs. This is not the same amount at all positions of the spring, and is different for the spring as installed. The first heating of the material comes when the end of the wire is stamped and the second heating process is when the wire is being rolled to a coil form. endstream endobj 209 0 obj <. The farther left the MC is located, the more efficient the front end will be and will want to roll. The reasons are easy. Antisquat results from the third link trying to straighten out, or become more horizontal as the car accelerates and the rear end desires to rotate. The following information applicable for most oval track Chrysler styles mono and multi-leaf leaf spring applications with the sliders mounted on the rear. 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. A common misconception is that arch affects free spring rate, which it does not. 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. Since each spring is bearing 50 pounds of weight, the 25 pound spring will compress two inches, and the 50 pound spring will compress one inch. by racerx1622 Thu Aug 25, 2011 5:51 pm, Post For instance, a 1300 lb/in spring may be 1325 the first inch, 1395 the second and 1460 the third inch. The rear stagger should be matched to the racetrack and not used to correct handling problems. Ackermann is easily checked by using a laser system or strings. Trends are a part of this learning curve and greatly influence some, but not all racers. 1/2" on RF (5 degree angle of Upper A-Frame mounting bolts), 1/4" on LF, front higher than back, average bolt height the same as before. The front moment center (MC) location plays a huge role in how the front end wants to work. For example, when the leaf springs are toed in (the front eye locations closer together than the rear mounts) the lateral rate or twisting resistance is increased, therefore ones side bite rate is increased. 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. One negative scenario is the fact that the right front compresses at a faster and compresses more than the left front, the chassis may tend to gain cross. DESIGN: Most coil spring failure is directly related to the design of the spring. The tire temperatures still supported his feel. If you could slide the MC to the right, or outside of the turn for you road racers, the front end will get stiffer. We have redesigned our website to give our customers a better online shopping experience. The effect is huge. If we arrange our control arm angles, from a side view, for antidive, then as the car dives the upper BJ would move to the rear and the bottom BJ would move to the front. Changing spring rates is a primary setup tool to get both ends of the car to match up . I plot them like its a ladder bar (if its right, wrong, backwards, I dont care it works for me) and had it setup with an IC of around 30 (20 inch front segment, 8 inchs off ground) With this setup the car went 9.98 with a pump gas small block and some spray but it was killing the tire. The dynamics of the moment center and the effects of camber change have been explained before. If you lightly brake into the corner and the problem diminishes, then brake bias is the culprit. In this tech article CIRCLE TRACK provides an asphalt chassis setup guide which delves into the critical elements of a well designed pavement race car to help you get prepared for the new season . 6. All the driver knows is that the car is loose. The car may or may not be neutral in handling, but the handling will not be consistent. As a result, the spring will tend to fail under loads. So, here is, in order of logic and importance, a list of setup parameters we need to address to make our cars fast and consistent. Since only the bottom spring is now the only one working, its rate is what the car runs on, as long as the shock is compressed to the predetermined point. 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. Published: Mar. Moreover, on super-speedways, the raised frame height will result in the car having to push too much air. The rubber, many times, will fall out due to the rigor of racing. These do not install with rubber isolators either. These lightweight clips simply cannot withstand the tremendous forces encountered in racing leaf springs. There are several things we can do to help balance the car. Although they are the oldest, they seem to be the least understood. Bump Steer Gauges; Canopies & Car covers; . With this system you can run a softer rate on the top and a stronger rate on the bottom. It is possible to have Ackermann in our steering system when we steer left and reverse Ackermann when we steer to the right. Bushingchoice can affect spring rates. TUNING THE CAR WITH SPRINGS REMEMBER: "STIFF SPRING GETS THE WEIGHT" Rear to front weight transfer (deceleration) POINTS TO REMEMBER: (1.) As a result, the inboard springs are mounted the softer the installed rate will be. Meaning that as the spring is compressing it is gaining rate. Antidive and antisquat are mechanical influences that can help our transitional phases of entry and exit. The engine should always be aligned perpendicular to the rearend and/or parallel to the centerline of the car. The spring will not have any consistent spring pre-load from one spring to another; as a result, the chassis will not respond consistently. I have always believed in priorities because you can make gains faster when you solve the high priorities problems first. 2. The springs length, width, thickness, number of leaves, hardness,bushings and clips determine the spring rate. These theoretical rates are just that, Theoretical. That troubles me. Knowing that every spring has its own characteristics, Landrum Spring, engraves the exact rate of each and everyGOLD COILto 1/10#. We have continually pressed these issues because of the extreme importance they have. In addition, the leaf spring suspension is more forgiving on chassis set-up errors. Measure from the main leaf to the datum line. LANDRUM PERFORMANCE SPRINGSmakes no guarantees that these charts will be suitable for each racers needs. It's no wonder. It has been found that the misalignment of your tires/wheels presents serious drawbacks to a finely tuned chassis and setup. If you stack a 10-inch 200 rate and 6-inch 200 rate spring, you get a combined rate of 100 pounds per square inch. What is important is how each tire is toed in or out in relationship to to the center line ofthe car.You can lead or trail the rear axle to get there but,setting the toe in the rearend housing first worked better for me.If the housing has 1/8 toe out heat the front of the tubes till red then throw cold wet rags on them.This will bend the tubes slightly if you go over 1/8 it could cause bearing trouble. This can cause an undesirable change in spring rate and wheel base settings. Welcome to our new website! Allstar Performance offers quality Circle Track Racing - Asphalt Suspension at a great price, check out our website today at allstarperformance.com. If the LR shock has too much rebound, then that tire will lose a lot of load and not be able to provide traction. Clipshave a profound effect on spring rates. Negative effects include limited number of spring cycles, loss of spring life, and loss in ride heights. If all of these issues are evaluated and corrected, then you can move on. These are the general rules unless you are trying to "tie down" a corner. Decrease the RF Spring Rate. Pivot bushings are bushings that were designed to remove the bind between the chassis and the spring. A typical problem is a spring that has excessive arch in the center. This puts undue stress on the leaf springs. Bite Off The Corners The leading edge of each leaf plays a role in determining spring rates. ASPHALT MODIFIED (Standard 3 Point and 4-Link Cars) 2006 Set-Up and Technical Guide. The tight or loose condition can exist in one or more of the three phases of a turn (entry, middle, and exit). The following spring/shock combinations are recommendations only. Alignment Transitional components include the shocks, rear roll steer, brakes, rear steer under power, camber change, rear stagger and the Anti's (dive and squat). When all three phases are balanced, work on driver finesse and practice passing maneuvers running high and low off the corners. Each end has its own moment arm length and resistance to roll as well as other factors. In turn, the life of the spring and the number of cycles is reduced. Many times hair-line fractures and cracks cannot be seen without the aid of a florescent penetrant inspection. In the next issue of CT, we will delve into the setup problems for a dirt car. If those desired angles are different, then we term the setup unbalanced. This insures properly made springs, guaranteed arch tolerances, access to complete labs for testing and research with technical racing experts to understand your requirements. On a metric four-link car, the four control arms determine the rear moment center height too. Excess stagger should never be used as a crutch to help make the car turn if it is tight. Recommended torque is 20 lbs. The other types of ends are the closed and open tangential ends. On the bottom of the leaf, you can get a better look at the segment clamps. Coil springs are the most common used spring in most all motor-sports today. Rubber bushings tend to absorb more energy and loads from the chassis and rear end, therefore the springs tend to last longer. Antidive effect can help the situation. Allstar Performance $44.99. With a Detroit Locker, or similar differential, the axles will unlock going in and through the middle and lock up on exit while under power. Proper U-bolt selection is critical, use only Grade 5 U-Bolts. In the common asphalt setups of today, where we use a larger sway bar and softer springs (BBSS), the presence of Ackermann effect could be more detrimental. We race a '76 Pontiac LeMans with the 4 link rear. The driveshaft alignment is critical from the standpoint of mechanical efficiency. Remove the spring from the car and place it on its side on the floor or a flat surface. It must show a consistent gain in performance and a logical ideology to the bulk of race teams. Furthermore,Landrum Springis recognized as the only company in the racing industry worldwide doing so. The setup is balanced when the LF and LR tire temps are similar. We can reduce the rear spring split if we are using a softer right-rear (RR) spring by stiffening the RR spring and/or reducing the LR spring rate. First, we needed to look at the previous setup to see what went wrong. The disadvantages of banding clips with rubber linings is that the rubber will absorb grease and brake fluids leading to deterioration of the components. The longer lever arm created by the adjustment scenario in the prior paragraph compresses the RF spring more than it would have in our baseline set up. Address: 304 5th Creek Road, Statesville, NC, US, 28625; Free Phone: 1-704-871-0817; 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. Ask your supplier what materials the spring consists of. Changing to a smaller sway bar increases the front roll angle, but not very much. When the front bushing is allowing the front leaf spring to pivot, it transfers all the side loads and lateral forces to rear portion of the leaf spring and shackles or sliders, which were not designed to handle the additional stress. Either of these two can be caused by an unbalanced setup or by running with the wrong amount of crossweight. One is called Stacked springs because all you are doing is stacking two springs in series, with the same or different rates, to achieve a longer spring that is softer rate than either of the springs used. Does it have actual print outs of each spring (data sheets)? DISPOSE OF DAMAGED SPRINGS:While springs are made of a high-tensile strength wire, they are susceptible to damage from impact. by 72firechicken Sun Jun 19, 2011 5:44 pm, Post The opposite occurs when the springs are mounted outward (closer to the wheels). Furthermore, because the front eye is allowed to pivot, it does not have any solid displacement to drive the car forward. If there are any marks or distortions on the spring they should be discarded. This malady is more common than most racers know. This tends to tighten the car on corner entry and through the middle of the corner. Initial camber settings must be revised when changing from conventional to BBSS setups. Leary sets the wedge in the springs and then adds additional wedge with 3-6 turns of preload and sometimes has winning success using 9 turns. If I have a split rate shock such as 3-5 and I turn the shock 180 degrees, will the shock then be a 5-3? Low-banked tracks require a location more to the left and higher banked tracks are best set up with a MC more to the right of centerline. Some manufactures even feel and state that racers should monitor a springs free height instead of its rate. When it happens on the right front, the chassis will gain bite. The steering system in your car must be evaluated and any negative characteristics must be eliminated. It doesnt solve the problem of multiple heat runs it simply tries to hide the fact. Conclusion The influence of the location of the front MC can be compared to a sliding scale. Decrease the Pre-Load on the Stabilizer Bar. 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. 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. The closer the leaf springs are mounted together (inboard), the more pressure the chassis exerts on the springs through physical leverage. The clip is installed by using a hydraulic press to assure proper tightness. With the BBSS setups, the front may want to out-roll the rear, causing excess load to be put on the right-rear tire through the turns. Welcome to Allstar Performance! . 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. Address: 304 5th Creek Road, Statesville, NC, US, 28625; If it is too far to one side, then changes to the brake master cylinder sizes and/or the pad compounds might need to be made in order to maintain a centered-bias adjuster. The optional third day of the Performance Driving course offers extended track time with more in-car coaching and driver development. If the wheel is turned farther at speed, the car is tight. The once tight condition now switches to loose as the front gains grip from excess steering angle. The front half of the leaf spring should be sufficient to control rapid positive torque. To accomplish a forged flat end, the spring material has to be heated more than once. We are at a crossroads at this point in time with setup technology in asphalt racing. Toggle menu. The right-side tire contact patches will also need to be inline with the right front tire pointed straight ahead. Coil springs wound with an inconsistent pitch will produce an inconsistent rate. 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. Aero Package Each and every data sheet clearly shows the pre load as well as the displacement that the spring was tested at. 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. The moment center must be located correctly for your type of racing and the cambers must be set, again toward your setup style and track conditions. The rear end should be at right angles to the chassis centerline, and the right side tire contact patches should be inline. By far the most common handling malady historically is inability to turn. On a three-link rear suspension you should have the front of your right-side control arm higher than the rear mount by 1/3 of the total amount it will travel in the turns. Not having true continuity between spring and jack plate is an undesirable trait. So, with some of the information we have learned over those years applied, here is a modernized version of that article. Take this into consideration when adding a fiberglass hood, aluminum heads, or when putting the battery in the trunk. Because the front tires generate more traction with a greater angle of attack, the driver is actually putting more traction into the front end. Decrease both Front Spring Rates. %PDF-1.5 % Leaf springs are the oldest form of suspension in racing. As we use the left-front tire more. The center of gravity (CG) height influences where the MC should be located. When this is severe, the front end will push and no adjustment to other setup parameters will seem to help the situation. Landrum Springas well as many top-level teams have found this to be counterproductive when setting up a car and compiling consistent results. SHOCK SELECTION The basics remain the same, but with a few critical adjustments. The new spring is tagged 2,200#; on the other hand, the unknown rate is 2,310#. No one including us can guarantee every spring to rate out exactly. Since the spring promotes rebound and resists compression as inherent properties, then the shock rate of compression control must be less than the rate of rebound control. EMERGENCY HELP CELL# 973.951.5135. Adding or removing as little as 50 pounds can also make a difference. Allstar Neck . Those were salvaged out of the old car and were perfectly fine. Increase the Rear Tire Stagger. 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. 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. Also, check out QA1's YouTube channel for tech, product and company videos! You may not be able to find a 16-inch 100 rate spring, so this provides more spring length to use. It is the purchasers responsibility to order the correct products through their personal racing experience. However, under racing situations, this may cause the chassis and rear end to have excessive movement, thus producing erratic handling. SAMPLES: A shackle with a 3 degree layback incorporates a stiffer installed rate than a shackle at 25 degrees layback. Steering Geometry You must try to determine if your setup is balanced and then if not, make the necessary changes to bring it into a balanced state. LIT-718 80291 1997 - 2004 Mustang Radiator. With the exception of U-Bolts LANDRUM recommends Permatex Anti-Seize on all leaf spring bolts, pivoting points, and slider components to promote free movement in the suspension. It is important to design the spring to its environment as well as its intended use. Lower the Rear Panhard Bar on both sides (frame and rear-end attachment). Yes, I get inquiries about how to apply the BBSS setups to both of these types of cars. Landrum designed their front drag racing coil springs to store energy for instant, maximum weight transfer for launching. This leads to bent shackles, warped sliders and misaligned axis points. Considering 4-link systems dominate the late-model market and even some classics, let's start there. Decrease the Split on the Rear Panhard Bar Heights. For example, if the main leaves are the same length and one spring has more arch, the spring with the most arch will have a stiffer installed rate. Tapered end leaves have a gradual decrease in thickness on each end. When it happens on the left front, the chassis will lose bite. 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. Hopefully the data contained in these pages was informative. 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. Here is a typical situation found at any given track. "In the 50-lap Main, our fastest lap time was clocked on Lap 43. In that time, a lot has changed with how racers on asphalt set up their cars. Setup With a big-bar Mike Leary of Leary Racing Shocks recommends adding wedge to the car by preloading the bar. If the geometry is such that the rear end is made to steer on turn entry so that the RR wheel is farther to the rear than the LR wheel, we have rear steer to the right. The use of softer front springs, larger sway bars, and big spring split in the rear has swept across the country for more than five years now with mixed results. As the front brakes are applied, the caliper grabs the rotor and the motion of the wheel/rotor tries to rotate the spindle. In some instances the manufacture may have to choose chrome vanadium wire, instead of chrome silicon. I'm not saying this is not important to some degree, but on short tracks I would stress that aero downforce is over-rated in most cases. I need some help with a 3450lb limited late model I race on a 1/3 light progressive banked mile ashpalt track 70 chevelle clip. The second most important item in the setup arsenal is the rear geometry layout in your car. Leaf springs possess many desirable suspension features, such as dampening, forward bite, roll over steer, high anti-squat percentage, and high lateral stiffness. What happens is that the car responds as if it has a stiffer spring on the left rear; however, because it has more arch, the spring is under a higher stress load. In the QA1 part numbers, which is first - compression or rebound? Stock cars using the metric-style four-link rear suspension usually need to do this just to achieve a balanced setup with the high rear moment centers in those cars. 10. Landrum Spring feels that forging has more negative than positiveeffects and should not be used in racing applications where accurately rated springs are crucial. There are ways to do that without changing the handling at other points around the racetrack. I have talked to racers who run on tracks that require 1.75 to 2.00 inches of stagger. Decrease Upper Control Arm Angle on the Rearend. Roughly 8-10 degrees of third link angle is sufficient to promote antisquat and not hurt your corner entry. Bushing choice will also affect spring life, and more importantly, spring performance. Note:To get the desired front end height (ride height), it may be necessary to modify the springs. So, there is a limit to how much you can get away with and still have a decent corner entry. We can raise the Panhard bar to raise the rear roll center, which will cause the rear suspension to want to roll less. The opposite of Ackermann is called reverse Ackermann. Using antidive on the RF and prodive on the LF helps square the front end to the racetrack and, along with a softer spring setup, provides an enhanced aero effect.
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