The rear stagger should be matched to the racetrack and not used to correct handling problems. The overall general rule is that the angles between the driveshaft and both the pinion shaft and the transmission output shaft need to be equal and in opposite directions. 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. PDF By Bob Bolles, Circle Track Magazine - Longacre Racing It is important to design the spring to its environment as well as its intended use. Address: 304 5th Creek Road, Statesville, NC, US, 28625; Free Phone: 1-704-871-0817; 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. Through our research, diamond trimmed leaves produce the most consistent spring rate. If too much of the bias is on the rear brakes, the car will be loose under heavier braking. It is this sliding scale situation that determines the stiffness of your front end. 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. Designed for drag racing where maximum weight transfer is needed. We also want to make sure that adjustments to other segments later on do not affect the mid-turn handling. Setting the Bar - JOES Racing Products The very last thing you need to worry about is your aero package. Stacking Springs for 2.5 Coil-overs. Plan out changes that could help improve performance or durability. If the front is diving under braking then add anti-dive to front suspension. The opposite holds true, the shorter the shackle, the faster the rate of change. 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). Another way to stack springs is to use the dual system. 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. Leaf-Spring Systems - The leaf-spring rear suspension system locates the rear-end fore and aft, as well as laterally using the leafs. Setup With a big-bar Mike Leary of Leary Racing Shocks recommends adding wedge to the car by preloading the bar. 1. The reasons are easy. Balance the Front and Rear stiffness. With the car set up correctly, it is just a matter of experience and a little racing luck that brings that first win. If all else were correct, such as alignment, Ackermann, setup balance, and so on, and the car was still tight or loose, then the crossweight percentage is probably wrong for the weight distribution in the car. Although they are the oldest, they seem to be the least understood. Leaf springs possess many desirable suspension features, such as dampening, forward bite, roll over steer, high anti-squat percentage, and high lateral stiffness. LANDRUM PERFORMANCE SPRINGSmakes no guarantees that these charts will be suitable for each racers needs. Reusing a damaged spring could have negative consequences. Forged ends are only desirable when mass production of a loose tolerance spring is acceptable, for example, the agriculture or industrial industry. I don't get too many reports of continual, repeated wins and successes. These data sheets clearly shows the details of the load in pounds of force, in increments of 1/10th of an inch for each and everyGOLD COIL. But the most useful rear steer will only occur on acceleration and not at mid-turn. It may take a few test sessions to help you determine your balance, but if you observe the indicators correctly, then tuning the car for dynamic balance can be done. 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. This system uses two springs on tip of each other in series. by racerx1622 Mon Aug 29, 2011 2:12 am, Post That troubles me. This induces rear steer when the car squats on exit. This puts undue stress on the leaf springs. 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. I can't tell you how many times I have refined the MC location in a car and had it totally change the way the car turned, for the better. Check Tire temps, if LF is coolest (unbalanced setup): Decrease front springs, maybe even use reverse split (LF stiffer). Anything you can do to give you more adjustabilty should be a positive.An eccentric bushing that is adjustable is something to look for.1'' wedge with a floorjack,I would be cutting up houseing and moving the pumkin.Swaybar preload and wheel offsets are areas to look at. We will look at each phase of the corner and offer handling remedies based on the phase they affect. Performance Driving | Radford Racing School 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. A tight condition is the number one complaint from drivers. Decrease LR Shock rebound and/or increase RF Shock compresion. A dampening shock may be used to tighten the car on entry. TRUE RATE OF A SPRING:Knowing the actual rate of each spring is crucial. 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. Measure from the main leaf to the datum line. Both of these are necessary components that will be needed to win championships. Other helpful hints are available from our technical experts. If it is turned less, it is loose. 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. When all three phases are balanced, work on driver finesse and practice passing maneuvers running high and low off the corners. This would mean we could align the driveshaft from a side view inline with the tranny shaft and the pinion shaft with no angular deflection. Changing spring rates is a primary setup tool to get both ends of the car to match up their attitudes. Solid bushings provide stable and predictable handling characteristics that lead to more consistent lap times. 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. Use a long (60 should be adequate) straight edge as a datum line. Good luck. The car may or may not be neutral in handling, but the handling will not be consistent. WAYS TO ENHANCE PERFORMANCE AND LONGEVITY OF LEAF SPRINGS. As a result, the inboard springs are mounted the softer the installed rate will be. When using stacked springs on a Dirt Late Model, this allows the car to run on a very soft spring rate on entry of the turn, until the heavier rate is needed through the middle and exit off the turn. 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. By far the most common handling malady historically is inability to turn. If the pitch is consistent, but too far apart then the spring will tend to take set and distort. A particular car at each racetrack will require a certain amount of rear stagger. Leaf springs are the oldest form of suspension in racing. 0 DATA PRINTOUTS:Having springs packaged with data information is crucial to any serious race team. Numerous car builders have come to realize the truth in the above statements. Also, common mishaps of spilling brake fluid or brake fluid contact from simply bleeding the brakes will deteriorate the rubber and break the composite down; therefore, the rubber will fall out and the clips will be loose and slide down the main leaf. The new spring is tagged 2,200#; on the other hand, the unknown rate is 2,310#. The components that locate the rear end must be evaluated and set correctly. We hope you enjoy shopping at Circle Track Supply, Inc. 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. 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. The dynamics of the moment center and the effects of camber change have been explained before. How to raise the cross weight in an iRacing asphalt setup. This system involves riveting the clips onto the leaves; the advantage is in preventing the clips from sliding up the leaf and becoming loose. Take this into consideration when adding a fiberglass hood, aluminum heads, or when putting the battery in the trunk. Installation Guides Spring Rate Tech Circle Track FAQs Below are some frequently asked questions. The influence of the location of the front MC can be compared to a sliding scale. On a metric four-link car, the four control arms determine the rear moment center height too. It must show a consistent gain in performance and a logical ideology to the bulk of race teams. HOPEFULLY THE INFORMATION CONTAINED IN THE TECHNICAL AREA HAS BEEN HELPFUL. Vintage/Classic/Historical Engine Tech, 3V Performance Engine & Valve train Development, Race Cars & Parts - For Sale or Wanted. LANDRUM SPRINGS engineers have found that by using two of the same spring rates, but installing one of the springs with a higher arch (for example on the left rear) is not recommended. When using coil springs on the rear, changes are made with spring rates not the free height of the coil springs. The stiff LF spring setup does not work well on tracks banked over 10 degrees. This happens when the crew knows there needs to be a spring split in the rear and installs a stiffer RR spring than the LR spring, but goes overboard and uses a RR spring that is much too stiff. Changing spring rates is a primary setup tool to get both ends of the car to match up . 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. 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. %PDF-1.5 % Meaning that as the spring is compressing it is gaining rate. Toggle menu. The rear end should be at right angles to the chassis centerline, and the right side tire contact patches should be inline. The installed rate is the rating of the spring as it is positioned within the chassis itself. In the QA1 part numbers, which is first - compression or rebound? Increase the Caster. 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. This applies equally to the shackle and slider ends. Increase the Angle of the Upper Trailing Arm. Although these changes will alter the height of the car, the spring rates will be unaffected as long as you stay within the guidelines. FYI, the springs shown here are stock ride height for a 1970 Nova. The leading edge of each leaf plays a role in determining spring rates. SAMPLES: Yes, I get inquiries about how to apply the BBSS setups to both of these types of cars. We were 0.13 faster than we qualified. When the shock travels, the divider between the shocks moves up the shock body. Initial camber settings must be revised when changing from conventional to BBSS setups. 241 0 obj <>stream 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.. That would be only on the r/r,you could toe the l/r out and the r/r in if the car needed it.If your housing has 1/16 toe out on the r/r you might need to shorten the wheelbase 3/4 to 1'' to get some toe in in the r/r.With r/r toe in the thrust angle of the tire is pointing toward the center of the car.When you pick up the throttle the r/r drives toward the infield and keeps the car tight letting you apply more power. I would try it. By Bob Bolles, Circle Track Magazine . asphalt metric street stock setup Bushingchoice can affect spring rates. 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. Clench clips (see Figure 2) have been proven to maintain a more consistent spring rate because of its ability to retain its clamping force. The idea is to steer the car using different height holes for the rear control arm mounts. If the front geometry is not designed correctly, then as the car dives and rolls, the RF camber relative to the racing surface will change and the tire will lose grip. When choosing a brand of coil springs several issues should be addressed. 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. 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. When running balanced setups that work the left-front tire, we must eliminate most of the Ackermann. The chassis was as good or better at the end than it was at the beginning.". 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. 2022 Landrum Performance Springs.All Rights Reserved. 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. You may not be able to find a 16-inch 100 rate spring, so this provides more spring length to use. 8. Squared end leaves produce high stress points in each leaf leading to premature failure of the leaf. Decrease the Split on the Rear Panhard Bar Heights. Maximum U-bolt torque for 1/2 diameter, plated U-bolts are 45 lbs. As the front brakes are applied, the caliper grabs the rotor and the motion of the wheel/rotor tries to rotate the spindle. Leaf spring geometry. Any links to good articles? Also, excessive torque of the shackle bolts will increase the installed rate. 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. Leaf Spring Suspension Performance Tips. 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. Suspension | Apex Customs Raise the front LR trailing arm mount. Moreover, on super-speedways, the raised frame height will result in the car having to push too much air. 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. The center of gravity (CG) height influences where the MC should be located. In addition, the leaf spring suspension is more forgiving on chassis set-up errors. On some tracks, with cars using Detroit Locker rear differentials, the accelerating portion radius will be larger than the mid-turn radius. 11, 2022 at 1:54 PM PST. Leaf Spring Setup | Team Camaro Tech Always use Grade 5 washers and deep well nuts. Also, the longer the shackle length, the slower the arc movement which decreases the rate of the spring change. Leaf springs possess many desirable suspension features, such as dampening, forward bite, roll over steer, high anti-squat percentage, and high lateral stiffness. This force is resisted by the ball joints and control amrs. Make small adjustments, about one half of one percent. They report running about 0.75 inch and complain that the car is tight off the corners. 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. Fiberglass Leaf Spring The fiberglass leaf spring is made of a mixture of plastic fibers and resin; it is lighter than all other springs. 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. CTS SUPER DUTY LEAF SPRING ROLLER STYLE SLIDER-CHEVY OR CHRYSLER STYLE. Tapered leaves have inconsistent run out, thus inconsistent spring rates. Remember that drag is an important aspect of aero design. Our extensive testing has proven this component to produce very erratic handling characteristics. The rubber, many times, will fall out due to the rigor of racing. 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. 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. The optional third day of the Performance Driving course offers extended track time with more in-car coaching and driver development. It consists of a center bolt that properly aligns the leaves and clips to resist its individual leaves from twisting and shifting. The more carbon removed from the material, the more hardness is removed from the wire. The following diagram illustrates a top view of the rear leaf springs which may be useful in determining a splayed or toed in pattern of the oval track Chrysler set up. The bottom line is that at mid-turn, each end will want to roll to its own degree of angle. Furthermore, because the front eye is allowed to pivot, it does not have any solid displacement to drive the car forward. Are their hidden cost in the spring purchased? When installing these springs, the arch will be pulled out, creating higher stress on the spring that will eventually decrease the life of the spring. In the next issue of CT, we will delve into the setup problems for a dirt car. Moving the pull-bar or just the third link to the left increases the loading on the LR tire during acceleration. LIT-722 C7 Z06 Corvette Heat Exchanger 80294NDP. Like anything else, all suggestions are just what they are "suggestions." All cars and drivers are not alike, but in general these are . Sliding the MC left and to the inside of the turn makes the suspension softer. MATERIALThe use of a high quality material such as chrome silicon steel is used to assure a long lasting spring that will maintain a consistent rate and hold free height over many cycles. Mid-turn handling problems are caused by a car that is either tight or loose. Allstar Neck . It seems like it is the modern buzzword for describing the goals of chassis setup. The setup is balanced when the LF and LR tire temps are similar. For example, ARCA and other type stock-car chassis whose accuracy of pit stop changes are a necessity. In the front-end geometry, there is a condition called Ackermann. By David Baker. Leaf spring rates can be increased or decreased based on the mounting positions and angles. If the car is diving excessively under heavy braking, the RF wheel will lose camber quickly and its tire will loose traction. Furthermore, the fiberglass spring is susceptible to damage from rocks and debris. 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. Adjusting That Rear End: Get Traction Under Control Lower the Rear Panhard Bar on both sides (frame and rear-end attachment). 2. The farther left the MC is located, the more efficient the front end will be and will want to roll. 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. by 72firechicken Tue Jun 21, 2011 1:34 pm, Post Powered by Stripe - Designed and Developed by. Decrease the Angle of the Upper Trailing Arm. 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. Antidive effect can help the situation. What really makes the setup work is precise shackle angles, the angle that you mount the shocks, and keeping that right rear free-moving." DISPOSE OF DAMAGED SPRINGS:While springs are made of a high-tensile strength wire, they are susceptible to damage from impact. Furthermore, band clips are frail and tend to break, stretch and fail under minimal contact (opponents right front fender hits your left rear spring). If the rear end is not aligned properly, the car may be either tight or loose in all three phases of the turns. This is how the spring segments are clamped together. Eliminate most of your bumpsteer and Ackermann and install the correct steering ratio for your track that would suite the driver. A too-tall spring may be lowered by cutting off a portion of a coil (usually around 1/4 to 1/2 of the coil). The engine should always be aligned perpendicular to the rearend and/or parallel to the centerline of the car. The open-end type springs are required when spring security of location is desired. The Antis One way is to have a rear spring split, where the right rear (RR) spring has less spring rate than the LR spring. The left side suspension usually is designed with about half the angle of the right side in a conventional design. 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.. Also, check out QA1's YouTube channel for tech, product and company videos! Listed below are the effects of spring arch. Asphalt Late Model-Super Late Model Panels and Kits; . So in some cases, using chrome vanadium for higher rated springs is a better choose than chrome silicon. The RF and LF wheels will always experience changes in camber as the car enters and rolls into the turns. Never over torque the stationary end (front eye) bolts, as it will prevent the suspension from moving freely. No more than 10-15 pound difference, excess split makes car tight. It is the purchasers responsibility to order the correct products through their personal racing experience. This is why the driver and the tire temps showed no change. As we use the left-front tire more and more, the negative results of Ackermann become more apparent. A poor handling car is defined as one that is either loose (rear has less traction than the front) or tight (front has less traction than the rear). Front End Geometry If you could slide the MC to the right, or outside of the turn for you road racers, the front end will get stiffer. LIT-719 80292 C7 Corvette Radiator. The setup that will stay consistent throughout the race is the one that wins, and balance provides that consistency. 4. Shocks & Springs - Circle Track Supply, Inc. Multi-leaf springs used for racing should incorporate leaves that are diamond trimmed on each end, not leaves that are tapered on the ends. An inconsistent clip, such as the Kwick Clip or Banding Clips with rubber insulation, will transfer into an inconsistent side bite. So don't try it. 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. "By using two springs in series, the dual setup allows them to have a softer ride . We mostly use the sway bar to tune for traction off the corners. Same weight, same board, but now let's use a 25 pound spring and a 50 pound spring. Behind the wheel of a Dodge Challenger SRT Hellcat Widebody, students will cover autocross, slalom, and accident avoidance, along with plenty of track time on the 1.6 mile Radford road course. Try to install shock rates to complement the car's setup. Simply grinding the spring flat after forging it is like putting excessive ketchup on a bad hamburger. Excess stagger should never be used as a crutch to help make the car turn if it is tight. The number one reason a car will be tight and not want to turn is because the front end is not designed properly. (2.)
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asphalt circle track leaf spring setup