If the wheel is turned farther at speed, the car is tight. 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). Increase the LF Spring Rate. The engine should always be aligned perpendicular to the rearend and/or parallel to the centerline of the car. Shocks & Springs - Circle Track Supply, Inc. One of the very first tasks in setting up a race car is to make sure all of the alignment issues have been corrected. Recommended torque is 20 lbs. We have redesigned our website to give our customers a better online shopping experience. Furthermore, band clips are frail and tend to break, stretch and fail under minimal contact (opponents right front fender hits your left rear spring). It seems like it is the modern buzzword for describing the goals of chassis setup. For instance, a J200 (5o.d. 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. Allstar Performance offers quality Circle Track Racing - Asphalt Suspension at a great price, check out our website today at allstarperformance.com. Brake bias influence can be easily determined by entering the corner with medium to heavy braking first and then entering with light braking to see if there is a difference. When choosing a brand of coil springs several issues should be addressed. Leaf Spring Technical Information. 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. 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. Causing the right front tire to have a higher tire temp, as a result, a shorter life of the tire. 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. It's no wonder. If the front is diving under braking then add anti-dive to front suspension. One should use the same free height, but change rates. Then a 2,000# spring could be anywhere between 1,900 to 2,100#. If you have to steer to the right at mid-turn, bring the car back in. Antisquat is detrimental to corner entry. Furthermore,Landrum Springis recognized as the only company in the racing industry worldwide doing so. There can be a small amount of rear steer as the. 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 is this sliding scale situation that determines the stiffness of your front end. Circle track leaf spring help - Don Terrill's Speed-Talk Because of restraints in design and the need for geometry controls for moment center placement, we have to live with those properties. The closer the leaf springs are mounted together (inboard), the more pressure the chassis exerts on the springs through physical leverage. When they are working together, the car is well on the way to a balanced state. One way is to have a rear spring split, where the right rear (RR) spring has less spring rate than the LR spring. Other helpful hints are available from our technical experts. Rubber bushings tend to absorb more energy and loads from the chassis and rear end, therefore the springs tend to last longer. Every race car needs a certain amount of tire stagger. At the end of the day, the springs where rated. Leaf springs are the oldest form of suspension in racing. Try to install shock rates to complement the car's setup. The amount of difference you need is directly influenced by the installed motion ratio of the spring and the spring rate. When using coil springs on the rear, changes are made with spring rates not the free height of the coil springs. Leaf springs possess many desirable suspension features, such as dampening, forward bite, roll over steer, high anti-squat percentage, and high lateral stiffness. So, there is a limit to how much you can get away with and still have a decent corner entry. Higher arch springs tend to work better on the dirt tracks whereas the lower arch springs perform better on the asphalt tracks. Toggle menu. Another way to stack springs is to use the dual system. We can also use prodive to hasten the movement of the left-front corner on turn entry. 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. Decrease the RF Spring Rate. 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. Reduce the crossweight in a tight car and increase the crossweight percentage in a loose car. by racerx1622 Mon Aug 29, 2011 11:34 pm, Post The current spring is tagged 2,000#; however, the unknown actual rate is 1,900#s. 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. Neck Mount 1.525in Black ALL14475. Not having true continuity between spring and jack plate is an undesirable trait. Performance Driving | Radford Racing School 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 reasons are easy. Phone: (585) 352-5590 Fax: (585) 352-5593 130 Buell Road Rochester, NY 14624 Asphalt Modified Set-Up . 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. by racerx1622 Thu Aug 25, 2011 5:51 pm, Post Speed up and do a few hot laps, and again note the position of the steering wheel. As we use the left-front tire more. Address: 304 5th Creek Road, Statesville, NC, US, 28625; 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. Frost Racing - Setup Tips A typical problem is a spring that has excessive arch in the center. On some tracks, with cars using Detroit Locker rear differentials, the accelerating portion radius will be larger than the mid-turn radius. Mid-turn handling problems are caused by a car that is either tight or loose. Proper U-bolt selection is critical, use only Grade 5 U-Bolts. And as for you Modified and Stocker class teams, don't even think about it. Multi-leaf springs used for racing should incorporate leaves that are diamond trimmed on each end, not leaves that are tapered on the ends. 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. 208 0 obj <> endobj Generally the spring rate will increase when the following is done or decrease on the opposite. Meaning that as the spring is compressing it is gaining rate. These do not install with rubber isolators either. Conclusion A slight amount of rear steer to the left has been shown to help provide more traction at the rear and bite off the corners where it is needed. This system involves riveting the clips onto the leaves; the advantage is in preventing the clips from sliding up the leaf and becoming loose. These types are desirable where stock lower control arms are used. In some instances the manufacture may have to choose chrome vanadium wire, instead of chrome silicon. As the front brakes are applied, the caliper grabs the rotor and the motion of the wheel/rotor tries to rotate the spindle. Be careful not to overdue that. Antidive effect can help the situation. That is the essence of shock technology related to handling influences. Allstar Performance $44.99. 0 Brake Bias This happens very quickly and the rear end snaps loose as the throttle is applied. 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. Racing Springs - Landrum Performance Springs If we have a top view difference in alignment between the transmission output shaft and the pinion shaft and they are parallel, then the angle to the driveshaft created by that misalignment might be sufficient to provide the needed angular differential needed for loading the U-joint bearings and reducing negative harmonics. How much does each spring compress? Leaf Spring Setup | Team Camaro Tech Another problem occurs with inconsistent resin mix which will cause the leaf to splinter and break. We always start with the front end geometry on any race car. There are several things we can do to help balance the car. Furthermore, the leaves should include Teflon inserts on each end to reduce inner leaf friction. Tapered end leaves have a gradual decrease in thickness on each end. The free rate is generally progressive, meaning that the leaf spring rate does not increase proportional to the rate of deflection. Reusing a damaged spring could have negative consequences. For example, if you want 250 lbs. In the front-end geometry, there is a condition called Ackermann. The number one reason a car will be tight and not want to turn is because the front end is not designed properly. 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. 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. Unbalanced setups exhibit easily observed characteristics, such as unusually high degree of wear and temperature on one tire versus the other tires. Forged ends are only desirable when mass production of a loose tolerance spring is acceptable, for example, the agriculture or industrial industry. The front end should always be weighed to ensure proper spring selection. The disadvantage of this style spring is that the spring rate has a progression in spring rate. LANDRUM SPRING is not responsible for any incorrect information listed. Like anything else, all suggestions are just what they are "suggestions." All cars and drivers are not alike, but in general these are . The more third link angle you have, the more antisquat there is. Changing to a smaller sway bar increases the front roll angle, but not very much. A very good set of adjustable shocks came with the car also and that helped us when it came time to do the setup. Same weight, same board, but now let's use a 25 pound spring and a 50 pound spring. Only use springs manufactured by companies such as LANDRUM SPRING that have a complete manufacturing facility. The basics remain the same, but with a few critical adjustments. 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. After the supposed spring change, the team then began to change shocks, sway-bars, and pan-hard bar heights. Knowing this,Landrum Springas elected to rate, dyno, print (numerical as well as graphical data), engrave each springs serial# and rate. 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. Now we have a slanted board! 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 . This puts undue stress on the leaf springs. Balance is spoken of in all types of motorsports these days, even F1. Pitch is the distance between the wires on any given coil-spring. We can raise the Panhard bar to raise the rear roll center, which will cause the rear suspension to want to roll less. 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. When not racing, keep the springs unloaded by simply placing a jack stand under the chassis frame rail. 241 0 obj <>stream Simply grinding the spring flat after forging it is like putting excessive ketchup on a bad hamburger. Coil springs are the most common used spring in most all motor-sports today. 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. The rubber, many times, will fall out due to the rigor of racing. Verify the leaf spring for consistency in the arch. The opposite of Ackermann is called reverse Ackermann. 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. LANDRUM SPRING has the proper mixture of chrome vanadium, carbon, manganese, silicon, nickel, molybdenum and tungsten. Pivot bushings are bushings that were designed to remove the bind between the chassis and the spring. endstream endobj startxref Doing this will probably make the car loose off the turns while under power. Numerous car builders have come to realize the truth in the above statements. DESIGN: Most coil spring failure is directly related to the design of the spring. You may not be able to find a 16-inch 100 rate spring, so this provides more spring length to use. After stiffing the spring to a 400# tagged spring the driver did not feel any changes. Through our research, diamond trimmed leaves produce the most consistent spring rate. 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. Let's stay with the circle track lingo. The track at Santan Junior High School is missing some info Please fill out the form below if you have the local knowledge to help your fellow runners. Antidive helps prevent sudden nose dive on entry by mechanically resisting the downward motion of the suspension using the rotational forces created through braking. Remember that drag is an important aspect of aero design. Considering 4-link systems dominate the late-model market and even some classics, let's start there. Increase the Angle of the Upper Trailing Arm. The spring rates and spring split across each axle help determine the desired attitude, or roll angle of that end of the car. You can decrease the spring rate by increasing the angle, or increase the rate by decreasing the angle. The other types of ends are the closed and open tangential ends. The disadvantage is that they produce inconsistent spring rates. We felt that more standardized rating would be helpful to everyone involved. EMERGENCY HELP CELL# 973.951.5135. For example, ARCA and other type stock-car chassis whose accuracy of pit stop changes are a necessity. By Bob Bolles, Circle Track Magazine . 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. Some orders may take longer than normal, we apologize for any delays (we are trying!) 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. Circle Track - Asphalt Chassis | Allstar Performance 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. 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. . Yes there's aftermarket springs that work great on there own to combat wheel hop if you don't want to or can't run traction bars. With the car set up correctly, it is just a matter of experience and a little racing luck that brings that first win. 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. Example the leaf will be 2 1/2 wide throughout its length, and .323 in thickness throughout its entire length. If all of these issues are evaluated and corrected, then you can move on. 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. 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. When this is severe, the front end will push and no adjustment to other setup parameters will seem to help the situation. by 72firechicken Thu Jun 23, 2011 2:12 am, Post 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.