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. Loss of efficiency can rob power from the drivetrain due to the generation of vibrations and harmonics that are also damaging to the bearings. This malady is more common than most racers know. Our extensive testing has proven this component to produce very erratic handling characteristics. 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. We mostly use the sway bar to tune for traction off the corners. So testing for the fastest lap does not guarantee success. Once it reaches a predetermined point, the divider hits the stop and the top spring is no longer able to compress. e; The less desired method is the forged or stamped method. by 72firechicken Thu Jun 23, 2011 2:12 am, Post Doing this will probably make the car loose off the turns while under power. The rate of a spring is the change of load per unit of deflection (N/mm). Examine the spring immediately upon receiving. 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). This not only insures consistent and proper spring rate, but also longer life (more cycles). Racing Shocks Setup Tips for Dirt and Asphalt Here are some racing shock setup tips you can apply at the race track. Decrease Upper Control Arm Angle on the Rearend. The installed rate is the rating of the spring as it is positioned within the chassis itself. Off-centered adjusters can be very inconsistent. by RCJ Tue Aug 30, 2011 9:30 pm, Powered by phpBB Forum Software phpBB Limited, Shocks, Springs, Brakes, Frame, Body Work, etc, Hi anybody out there have any experience with rear leaf spring suspensions? on the right rear, you should not install a taller spring on the left rear with the same spring rate as the right rear. If all of these issues are evaluated and corrected, then you can move on. A very soft spring would need more compression rate and less rebound rate, whereas a stiff spring would need a lot of rebound rate and much less compression rate. The rear stagger should be matched to the racetrack and not used to correct handling problems. It's no wonder. The reason I say that with confidence, is because I have gone up against more aero efficient cars with setups and body configurations that were aero-deficient and still out ran them. Choosing too light of a spring rate will cause the spring to be in a higher stress situation, thus losing ride height. 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. However, under racing situations, this may cause the chassis and rear end to have excessive movement, thus producing erratic handling. Shackle angledetermines the rate as well. After the supposed spring change, the team then began to change shocks, sway-bars, and pan-hard bar heights. 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. This induces less rear steer when the car squats on exit. When running balanced setups that work the left-front tire, we must eliminate most of the Ackermann. It helps to install brake bias gauges and then adjust the amount of pressure front to rear. Adjust Cross Weight as changes are made to keep the car neutral. asphalt metric street stock setup asphalt metric street stock setup on March 30, 2023 on March 30, 2023 If too much of the bias is on the rear brakes, the car will be loose under heavier braking. Although they are the oldest, they seem to be the least understood. Our springs are available in a wide range of sizes and rates. The effect will be a lack of forward and side bite under acceleration. It's been three years since we discussed the subject of handling fixes. The disadvantage is that they produce inconsistent spring rates. 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. If we are loose going into the corner, the LR shock may be too stiff in rebound or the RF shock may be too soft in compression, which transfers load off the LR tire on initial entry under hard braking. The wine-and-cheese crowd refers to these as oversteer and understeer. The RF and LF wheels will always experience changes in camber as the car enters and rolls into the turns. The disadvantage is that the spring will not tend to lock in place and may turn in the control-arm bucket. Note:To get the desired front end height (ride height), it may be necessary to modify the springs. The very last thing you need to worry about is your aero package. and a 200 lb. 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. 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. 4. Engineered to hold a great amount of stored energy for instant weight transfer. Try to understand how aero downforce is created and then configure your car so that you take advantage of every area where you could produce more downforce. Plan your shock layout by comparing the stiffness of one to the other corners and to the spring stiffness at the corner you are trying to control. Negative aspects might include excessive bumpsteer (more than 0.030 bump in or out in for each inch of travel is considered negative by most designers), excessive Ackermann (more than a 1/4 degree added steer in either front wheel in 10 degrees of steering input is considered excessive), and incorrect steering quickness. In addition, the leaf spring suspension is more forgiving on chassis set-up errors. The farther left the MC is located, the more efficient the front end will be and will want to roll. It must show a consistent gain in performance and a logical ideology to the bulk of race teams. Through interviewing various teams, we found that current spring suppliers were using many various methods of rating coil springs. 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. Some rear suspension systems can be adjusted for rear steer. Leaf spring rates can be increased or decreased based on the mounting positions and angles. 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. It just won't work. On the bottom of the leaf, you can get a better look at the segment clamps. 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. DESIGN: Most coil spring failure is directly related to the design of the spring. Disc brake spacers will further impact the height. Reusing a damaged spring could have negative consequences. 5. Rear Geometry The car is loose right at mid-turn and off the corner. Drag Racing Front Spring Tec. The completely closed-ends are used when the requirement is that rate remains more consistent throughout the coil springs travel. Long gone are the days of saying that the MC is not important. Installed rateis another rate all together. We do not want to try to solve turn entry problems with the brake bias, we only need to make sure the car stays neutral in handling when the brakes are applied. We also want to make sure that adjustments to other segments later on do not affect the mid-turn handling. When not racing, keep the springs unloaded by simply placing a jack stand under the chassis frame rail. An unbalanced car can be very fast, although the thrill lasts but for a short time. 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. We are at a crossroads at this point in time with setup technology in asphalt racing. The spring will not have any consistent spring pre-load from one spring to another; as a result, the chassis will not respond consistently. DATA PRINTOUTS:Having springs packaged with data information is crucial to any serious race team. Welcome to our new website! Furthermore, these solid bushings control and enhance chassis performance by resisting chassis roll/torque. Welcome to Allstar Performance! As a result, the inboard springs are mounted the softer the installed rate will be. The right-side tire contact patches will also need to be inline with the right front tire pointed straight ahead. The opposite occurs when the springs are mounted outward (closer to the wheels). The more carbon removed from the material, the more hardness is removed from the wire. The bottom line is that at mid-turn, each end will want to roll to its own degree of angle. Increase the Rear Tire Stagger. It is the purchasers responsibility to order the correct products through their personal racing experience. In addition, the choice of this material will allow a manufacture to wind the spring out of smaller wire to incorporate a larger pitch, which will inadvertently allow more travel and produce a lighter weight spring. These springs tend to stay locked in place when the suspension is unloaded; for instance, changing a tire during a pit stop. LIT-A950700016 80275NDP Ford Mustang Cobra HE. Inspect the end of the spring wire, if it appears to be splayed or tapered you can rest assure the ends have been forged. by 72firechicken Wed Jun 22, 2011 3:46 pm, Post This develops more crossweight as the car squats on acceleration. They report running about 0.75 inch and complain that the car is tight off the corners. The stacked spring concept is being used on the left rear, right front and sometimes on the right rear to fine tune the race car. Flat end springs are achieved in two different ways, ground or forged. Multi-Leaf springs used for racing should have a clench clip type 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. Impact from tire hopping or grazing the wall can bend or unroll the main leaf eyes. Allstar Performance offers quality Circle Track Racing - Asphalt Suspension at a great price, check out our website today at allstarperformance.com. Use a long (60 should be adequate) straight edge as a datum line. If a manufacturer decides to produce a spring utilizing chrome silicon (.625) wire in lieu of a .710 where the stress levels are too high, then the spring will more than likely loose free height, take set and even in some cases break. Every race car needs a certain amount of tire stagger. Proper U-bolt selection is critical, use only Grade 5 U-Bolts. Shocks by RCJ Wed Jun 22, 2011 9:05 am, Post 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.

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