Decrease the Pre-Load on the Front Stabilizer Bar. Furthermore, the spring will absorb all the weight transfer, and not plant the tire securely on the track. Bushingchoice can affect spring rates. The effect is huge. Softening the LF and/or stiffening the RF spring increases dynamic wedge during deceleration. SERIAL NUMBER:Having a spring that has its own serial number is important. Furthermore, the crew made unnecessary changes, wasted valuable time, resulting in wear and tear on the engine, tires and other components. If the shackles are long and do not have any middle support or bracing, then the shackle tends to absorb more of the twisting instead of the spring; therefore, your lateral resistance is less. 8. The information below is applicable for most oval track Chevrolet styles, parabolic and multi-leaf leaf spring applications. A dampening shock may be used to tighten the car on entry. Leaves that are tapered on the ends are generally used for mass production applications which do not require the close tolerances and consistency in the spring rate that racers demand. Next, tune the entry balance and then tune the exit balance. For example, if the spring industry standard is say 5%. 6. The advantage of this style is that the spring is lighter than the multi-leaf. Decrease LR Shock rebound and/or increase RF Shock compresion. This malady is more common than most racers know. LIT-718 80291 1997 - 2004 Mustang Radiator. In the front-end geometry, there is a condition called Ackermann. Decrease the Angle of the Upper Trailing Arm. If the front is diving under braking then add anti-dive to front suspension. You can decrease the spring rate by increasing the angle, or increase the rate by decreasing the angle. This condition is very hard to detect from a driver's perspective. 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. 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. Stiffening the LF and/or softening the RF spring decreases dynamic wedge during deceleration. In addition, as the spring is put under load the shackle angle increases; therefore, the spring rate decreases under travel. The installed rate is the rating of the spring as it is positioned within the chassis itself. The driveshaft alignment is critical from the standpoint of mechanical efficiency. by racerx1622 Mon Aug 29, 2011 11:27 pm, Post DATA PRINTOUTS:Having springs packaged with data information is crucial to any serious race team. Chrome silicon generally comes only in no larger than a .625 size from wire suppliers in the USA. When all three phases are balanced, work on driver finesse and practice passing maneuvers running high and low off the corners. Measure the angle derived from the two lines. If the pitch is consistent, but too far apart then the spring will tend to take set and distort. Ackermann is easily checked by using a laser system or strings. 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. Loss of efficiency can rob power from the drivetrain due to the generation of vibrations and harmonics that are also damaging to the bearings. Choosing too light of a spring rate will cause the spring to be in a higher stress situation, thus losing ride height. 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. The bottom line is that at mid-turn, each end will want to roll to its own degree of angle. Adding or removing as little as 50 pounds can also make a difference. The opposite of Ackermann is called reverse Ackermann. Now we have a slanted board! Setting the Bar - JOES Racing Products Still, teams want the most they can get out of their cars and if all of the above nine items are in order, by all means, go ahead with aero tweaking. Softer grades tend to stretch under stress created while tightening instead of maintaining compression between the spring and axle perch. 2. 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. 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. Another problem occurs with inconsistent resin mix which will cause the leaf to splinter and break. 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. If the car is diving excessively under heavy braking, the RF wheel will lose camber quickly and its tire will loose traction. The settings, including the moment center location, really do dictate how all of the other parts and pieces of setup will work. The following information applicable for most oval track Chrysler styles mono and multi-leaf leaf spring applications with the sliders mounted on the rear. This is the true arch of the spring. Let's stay with the circle track lingo. If too much of the bias is on the rear brakes, the car will be loose under heavier braking. Some teams refuse to run sufficient stagger to match the radius and banking of the racetrack. The components that locate the rear end must be evaluated and set correctly. It is this sliding scale situation that determines the stiffness of your front end. So don't try it. WAYS TO ENHANCE PERFORMANCE AND LONGEVITY OF LEAF SPRINGS. 4. HOW TO EXAMINE AND CHOOSE YOUR HIGH PERFORMANCE LEAF SPRING. 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. Frost Racing - Setup Tips 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. Tapered leaves have inconsistent run out, thus inconsistent spring rates. These types are desirable where stock lower control arms are used. 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. On some tracks, with cars using Detroit Locker rear differentials, the accelerating portion radius will be larger than the mid-turn radius. Not having true continuity between spring and jack plate is an undesirable trait. 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. Below are suggestions on selecting a spring for your application. So the actual change in spring rate was not an increase of 25# as was intended but a decrease of 2#. 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. We are only talking about a difference of 0.040- to 0.060-inch, but that is enough to help stabilize our car on exit and provide added bite. Bump Steer Gauges; Canopies & Car covers; . The spring will not have any consistent spring pre-load from one spring to another; as a result, the chassis will not respond consistently. Leaf springs are the oldest form of suspension in racing. Our extensive testing has proven this component to produce very erratic handling characteristics. (2.) 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. Speed up and do a few hot laps, and again note the position of the steering wheel. When it happens on the left front, the chassis will lose bite. 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. hb```9,"o@(Yf8 rijYd`Pu9s9`*fm3 fxEGG;`(1Aja;ZYm @PfdPhv` } >--`;Xo!H^`(, H)3](c0 Ri I don't really encourage that method. by RCJ Mon Aug 29, 2011 9:19 pm, Post 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? Circle Track Setup: Springs 101 - iRacing.com HOPEFULLY THE INFORMATION CONTAINED IN THE TECHNICAL AREA HAS BEEN HELPFUL. Here are what we consider to be the 10 most important areas of chassis setup with No. Flat end springs are achieved in two different ways, ground or forged. 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. 11, 2022 at 1:54 PM PST. Here is an explanation of balance related to the dynamics of the race car. When this is accomplished correctly, spring rates and reactions can be more accurately predicted which in turns makes the chassis more predictable. Sometimes the car is tight and the driver turns the steering wheel far enough to get the car to turn. The rear end should be at right angles to the chassis centerline, and the right side tire contact patches should be inline. We have redesigned our website to give our customers a better online shopping experience. It is possible to have Ackermann in our steering system when we steer left and reverse Ackermann when we steer to the right. Multi-Leaf Spring This type of leaf spring has more than 1 leaf in its assembly. The upper BJ is trying to be forced in a forward direction and the lower BJ is trying to be forced in a rearward direction. Increase the LF Spring Rate. Leaf springs possess many desirable suspension features, such as dampening, forward bite, roll over steer, high anti-squat percentage, and high lateral stiffness. 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. $119.99; 119 - Reward points. 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. It helps to install brake bias gauges and then adjust the amount of pressure front to rear. These bushings produce a solid rear housing displacement for added traction. Remove the spring from the car and place it on its side on the floor or a flat surface. 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. The effect will be a lack of forward and side bite under acceleration. The Antis 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. x 13tall x 200# coil spring) may be engraved 201.8. Causing the right front tire to have a higher tire temp, as a result, a shorter life of the tire. When the LR tire is the coolest on the car, the rear spring split may be too much. lowers roll steer (tightens car on corner entry), increase pan hard rate (may tighten car in center of corner), lowers roll center (decreases chassis roll), raises roll steer (loosens car on corner entry), decrease pan hard rate (may loosen car in center of corner), raises roll center (increases chassis roll). The chassis was as good or better at the end than it was at the beginning.". Good handling has often been thought of as a car that is neutral as it runs through the entry, middle, and exit phases of the corner. I would try it. EveryGOLD COILhas its own dyno sheets incorporated in its box when leaving our facility. We felt that more standardized rating would be helpful to everyone involved. These set-ups are to provide a reference only. Increase the Angle of the Upper Trailing Arm. 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. by 72firechicken Wed Jun 22, 2011 3:46 pm, Post Do not seek aero downforce at the expense of aero drag increase. Furthermore, the fiberglass spring is susceptible to damage from rocks and debris. That is the essence of shock technology related to handling influences. There are ways to do that without changing the handling at other points around the racetrack. 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. Alignment Installing a torque device combined with these types of suspensions will cause the wrap-up rate to be excessive. 7. Powered by Stripe - Designed and Developed by. PDF By Bob Bolles, Circle Track Magazine Remember that drag is an important aspect of aero design. In addition, the leaf spring suspension is more forgiving on chassis set-up errors. Circle Track - Asphalt; Circle Track - Dirt; Open Wheel - Sprint Car; Off-Road & Tractor Pulling; All Categories ; Shop By Price $0.00 - $98.00 . can develop a winning setup. Always use Grade 5 washers and deep well nuts. We run a monoleaf on the right and a stacked leaf on the left. Place the straight edge on the spring so that it intersects the front and rear bushing. Address: 304 5th Creek Road, Statesville, NC, US, 28625; Free Phone: 1-704-871-0817; 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. Leaf spring mounting angles are one of the most important factors in a leaf spring system. Also, by increasing the lowering block height, one will be raising the axle height or lowering the front eye which will increase chassis roll. 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. Eliminate most of your bumpsteer and Ackermann and install the correct steering ratio for your track that would suite the driver. If the transition is abrupt and the top of the track drops to match the inside edge elevation, then the RF will follow the drop-off and unload the LR wheel. Examine the spring immediately upon receiving. If you have to steer to the right at mid-turn, bring the car back in. A-Arm length and mounting height have a dramatic effect on Instant Center Location. Take this into consideration when adding a fiberglass hood, aluminum heads, or when putting the battery in the trunk. The springs are tall and constructed from small-diameter, high-tensile chrome silicon wire, providing the correct rate for the listed application. Rear Steer Design - Chassis Setup For Improved Cornering - Circle Track Front End Geometry Some rear suspension systems can be adjusted for rear steer. 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. Spring rates range from 200-pounds to 225 pounds, plus you can specify three ride heights. Even though the winding process using CNC automated equipment is consistent, the variances in the quality of spring wire is not as consistent. Changing to a smaller sway bar increases the front roll angle, but not very much. The farther left the MC is located, the more efficient the front end will be and will want to roll. Negative effects include limited number of spring cycles, loss of spring life, and loss in ride heights. A very good set of adjustable shocks came with the car also and that helped us when it came time to do the setup. 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. A loose or tight car can also be caused by a tight or loose setup. The tight or loose condition can exist in one or more of the three phases of a turn (entry, middle, and exit). The farther to the right of the centerline, the less the front end will want to roll. The shape of the racetrack can affect how the car is balanced when exiting the turns. This tends to tighten the car on corner entry and through the middle of the corner. It's been three years since we discussed the subject of handling fixes. Transitional components include the shocks, rear roll steer, brakes, rear steer under power, camber change, rear stagger and the Anti's (dive and squat). I talk to lots of racers representing every form of circle track racing in every region of the country and beyond. Roughly 8-10 degrees of third link angle is sufficient to promote antisquat and not hurt your corner entry. The amount of difference you need is directly influenced by the installed motion ratio of the spring and the spring rate. Rubber bushings tend to absorb more energy and loads from the chassis and rear end, therefore the springs tend to last longer. This is why the driver and the tire temps showed no change. Most teams that do this also run the BBSS setups and desire to drop the front end as low as possible and as quickly as possible on turn entry. 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. The actual total spring change instead of 200#s is 410#, over 100% more or twice the spring change desired. However, it does affect the installed rate. This can be caused by several different conditions, or a combination of those. On parabolic and multi-leaf applications, it is not recommended to run a torque device, such as a torque arm or a spring or rubber torque link. Leaf Spring Technical Information. The following spring/shock combinations are recommendations only. As each season comes along, our knowledge of what we need and desire grows. For example, if you want 250 lbs. Most companies incorporate a metal tag denoting the theoretical rate of each spring. You may not be able to find a 16-inch 100 rate spring, so this provides more spring length to use. This leads to bent shackles, warped sliders and misaligned axis points. However, the negative effects of these bushings greatly outweigh their intended purpose. Considering 4-link systems dominate the late-model market and even some classics, let's start there. 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. Every race car needs a certain amount of tire stagger. Just giving the car more rear traction, period, does not help us if the car becomes too tight in the middle of the turns and we could end up with the reverse of what we need. 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. 208 0 obj <> endobj But if your running a stock 4 or 5 leaf set up. 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. On a metric four-link car, the four control arms determine the rear moment center height too. The reason less shackle angle, more preload on each leaf, and a taller resistance line. Rear Suspension - Circle Track Supply, Inc. Long gone are the days of saying that the MC is not important. 2022 Landrum Performance Springs.All Rights Reserved. Changing spring rates is a primary setup tool to get both ends of the car to match up . The lateral location of the third link can affect the distribution of load among the two rear tires that results from acceleration and antisquat. Racing Springs - Landrum Performance Springs The very last thing you need to worry about is your aero package. on the left rear and 225 lbs. How much does each spring compress? Hopefully the data contained in these pages was informative. 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. Try to install shock rates to complement the car's setup. We race a '76 Pontiac LeMans with the 4 link rear. As we use the left-front tire more and more, the negative results of Ackermann become more apparent. The setup is balanced when the LF and LR tire temps are similar. The overall rate and the layout of different shock rates on the car can greatly affect the weight distribution, and therefore the handling, in the transitional phases on the racetrack. The car is loose right at mid-turn and off the corner. I don't get too many reports of continual, repeated wins and successes. As we use the left-front tire more. Rear Geometry All the driver knows is that the car is loose. 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. 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. FYI, the springs shown here are stock ride height for a 1970 Nova. If you could slide the MC to the right, or outside of the turn for you road racers, the front end will get stiffer. Simply grinding the spring flat after forging it is like putting excessive ketchup on a bad hamburger. At the front end, we can do a few things to cause the front to roll more to try to match the rear roll angle. Spring training schedule released; Here's when Cactus League starts The car may or may not be neutral in handling, but the handling will not be consistent. The car came with everything the team needed except the motor and tranny. 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. It doesnt solve the problem of multiple heat runs it simply tries to hide the fact. If the rear end is not aligned properly, the car may be either tight or loose in all three phases of the turns. Adjust Cross Weight as changes are made to keep the car neutral. SHOCK SELECTION Shocks affect the motion of the corners of the car and therefore the placement of loads during transitional periods. The number one reason a car will be tight and not want to turn is because the front end is not designed properly. 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. PDF By Bob Bolles, Circle Track Magazine - Longacre Racing It has been found that the misalignment of your tires/wheels presents serious drawbacks to a finely tuned chassis and setup. The rate of a spring is the change of load per unit of deflection (N/mm). Measure from the main leaf to the datum line. This happens very quickly and the rear end snaps loose as the throttle is applied. If there is, try to adjust the brake bias to eliminate the adverse condition. Recommended Basic Setups. Squared end leaves produce high stress points in each leaf leading to premature failure of the leaf. The open-end type springs are required when spring security of location is desired. In turn, the life of the spring and the number of cycles is reduced. 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. 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. Reusing a damaged spring could have negative consequences. Once you've made the entry to the corner balanced, check to see if the adjuster is centered. Decrease RR Trailing Arm length by 1/8 inch. Leaf springs are the oldest form of suspension in racing. 9. 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. Here is a recent quote from a reader who has found that perfect balance. We should start with the mid-turn handling because problems that affect the car in the middle can also affect the entry and exit. Let's go through each item and explain how they can affect our turn entry and exit performance. It is important to design the spring to its environment as well as its intended use. Phone: (585) 352-5590 Fax: (585) 352-5593 130 Buell Road Rochester, NY 14624 Asphalt Modified Set-Up . Racing Shocks Setup Tips Because of restraints in design and the need for geometry controls for moment center placement, we have to live with those properties. 5. 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. 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. Steering Geometry TUNING THE CAR WITH SPRINGS REMEMBER: "STIFF SPRING GETS THE WEIGHT" Rear to front weight transfer (deceleration) POINTS TO REMEMBER: (1.) 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. We will need to go through a checklist to eliminate some familiar problems. Antidive helps prevent sudden nose dive on entry by mechanically resisting the downward motion of the suspension using the rotational forces created through braking. and a 200 lb. Lower the Rear Panhard Bar on both sides (frame and rear-end attachment). For example, while testing at Charlotte, a car had a 375# tagged spring in the rear, the driver felt that the car was loose on corner entry and the Hoosier tire temperatures supported his feel. This prevents undesirable chassis and rear end movement, thus creating favorable synergy between the chassis, springs and rear end. One way is to have a rear spring split, where the right rear (RR) spring has less spring rate than the LR spring. dQ#A$70 Q,6D|B@1" hKF? LIT-722 C7 Z06 Corvette Heat Exchanger 80294NDP. Knowing this,Landrum Springas elected to rate, dyno, print (numerical as well as graphical data), engrave each springs serial# and rate. 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.. The springs length, width, thickness, number of leaves, hardness,bushings and clips determine the spring rate.