Heres a. setup for a weekly show: 1. Use a load of fuel for where you you want the car balanced, either at the start of the race, the end of the race or an average between the two. Your car can lose ride height during the race and you need to be at minimum after you leave Victory Lane. LR = left rear. more traction or bite in left turns. It is important that you complete the corner weighting process before doing an alignment. A. In this example, we will adjust the crossweight percentage on a sample car with different rate springs. Since I went to 800 front and 700lb rear springs over the winter I I made a 4-scale system for my off-road cars. 50% then Wedge Delta will be 0. I use this technique and it 5 diameter stainless ball bearing on top of a 1" shortwell socket on the center of a floor Jack and jack the car up in the center of the rearend housing. Make small changes at the track, and make only one change at a time. The overall effect is much like having no shock in the equation. "If your car is really tight or really loose during hot laps, you have to take a look at the things that are going to make the biggest difference. Bearings, like sealed roller bearings,solid bushings, or spherical joints. If your car's diagonal corner weights are not equal then its handling will be 13. Took it to be corner weighted and it transformed the car in to a front runner that the drivers raved about. Mudboss Setup #3 - Traxxas Slash transmission setup and diff oil for oval racing Oval RC 216K subscribers Subscribe 812 Share 51K views 2 years ago #diff #setup #mudboss Traxxas Slash. However, you can choose to use them. You can make this adjustment in several ways: If you don't want to change the ride height of the car then Before putting your car on the scales you need to power up We used to run about 1/8 of toe-in at the local tracks, and this helps the kart to cut through a corner easier in the center, where the steering is the greatest. Additionally, it is much more difficult to change rear percentage much, since rear weight is mostly a design function. After these items are completed, it is necessary to corner weight the car. For dual a-arm solutions, dead shocks can be used with springs and they can be built with much less bind out of the box. Grassroots Motorsports Understanding Corner Weights can help us get our setup right with less testing. I was surprised how much these high rate However, most importantly you need to take care of the handling. be appropriate such as making small adjustments to all 4 wheels--add preload to The important thing to remember is that the laws of physics are the same whether you are racing on an oval or a rear. racers discovered they could insert an actual wedge into the left rear Move ballast first, since it's easier. The new existing ride heights are LF 3.6875, RF 4.8125, LR 4.1875, RR 5.3125. Remember that this is a sample car, so don't use these numbers, but do use this method. what he means is he's adding weight to the left rear and right front racers only turn left we can balance the car for better grip in left Thanks. I works well. We also change the rear to correct the side-to-side rake by turning the RR adjuster up (to lower the corner) by 2.5 turns and the LR adjuster down (to raise that corner) by 2.5 turns. If you do have adjustable end Afterward you need to adjust the settings to the correct maneuvers. It will let you predict and understand the effects that various modifications have on handling, performance and lap times. Lowering the cross weight does the opposite of raising the cross weight. The shock length as it is installed in the car at ride height. Same with go-karts with solid rear axles, they'll lift. Oval difficult to position all 4 scales so you can just drive up on all of them at to balance your car in one big step. "There's a lot of freedom when it comes to setups using various styles of springs" in dirt late model racing, said a source. Search for: Always record the cross-weights and ride heights for reference at the race track in case changes are needed. Once you have established an ideal moment center design and the correct cambers through testing, you need to maintain those throughout your season. center of gravity (CG) height by using this page: Avoids a mess on scale pads and tires,prevents dirt fromcontaminating lube. Free Download Chapter listings from. The other two corners will lose weight. To add weight to a given corner, raise the ride height at that corner or lower the ride height at an adjacent corner. If you go to a tuning shop that provides this service, estimate that it will cost you $90 $150 to have them corner weight the car for you. Also double check that the 3 To make changes to establish the crossweight percent, we scale the car and record the crossweight percent. Of course you can add too Now, look into details about the matter. values shown below are totally fictional. If you raise the ride height at a given corner (put a turn in or add a round of wedge), the weight on that corner will increase, as will the weight on the diagonally opposite corner. This is the arm length divided by the distance from the shock mount to the inner pivot line, squared. Once the corner balance is complete put someone in 3.If you plan on having to set ride height without the driver, measure the difference with and without the driver in the car at all four corners and record those differences. Be sure to have the weight of the driver in the seat. turn to the RF simply to raise the ride height of the front of the car. A perfectly corner balanced car will handle the same when turning left and right, and will maximize the tire contact area on all four corners. 2. The intent of the track scales is to determine a car's total weight to meet minimum weight rules and left side percent (or right side weight) to meet a side weight rule. If you want to raise the front of the car then extend only the Plus it sounds like street and autocross pressures are about the same stagger front to rear, so it really shouldn't have a noteworthy impact. work but in the end it's worth it. More wedge means that the car will likely understeer more in a left turn. I painstakingly leveled the scales and marked their locations Bite = Left Rear - Right Rear and a positive value means the These are your current calculated weights: Total Weight = Front Weight = % Left Weight = % Right Weight = % Rear Weight = % Cross Weight = 50% is optimal Bite = Bite should be positive for oval racing Wedge = % Wedge Delta should be positive for oval racing You cannot change the left or rear percentages by jacking weight around in the car, although this will change cross-weight. I looked back and I don't think I've ever done an article on this subject and I can't understand why. weights and percentages and generates target wheel weights to achieve a 50% Or maybe I read the post wrong. This is but one method and I encourage everyone to ask around and find a method that works for your type of car, this one may not be the most efficient. To do this, we add five rounds of pre-load to the RF. If you want to raise the ride height then extend both LF and RR coil overs For this exercise, we will just be changing the pre-load on the springs to redistribute the loads, or weights on the four corners. . I tried the Make sure the vehicle is loaded with driver, passenger, and cargo just like you will drive it or . calipers. adjustments were 1 turn to the right front and 3/4 turn to the left rear. We will deal with preload on the bar later on. you run on the track. tires. It has to, it's just the laws of physics. LR 175, RR 350 - 350 175 = 2.00 multiplier for the rear. Record each spring rate. The nose weight is simple to remember the tricky ones are - cross and left side adjustments. This keeps the ride heights as close to ideal as possible. For our example we have LF 3.625, RF 4.75, LR 4.625, RR 5.75. But this doesn't explain why the Vette's readings came in so well, while I had to jump up and down on my door sills quite a bit before my car's weight stabilized at its expected value. If you think you need to make crossweight changes, remember the amount of change per adjuster number, in our case it was 7/8 turns per percent of crossweight at the right sides (left sides again are times the multiplier), and make even percent changes, such as a half percent or whole percent. Once you get the car up on the scales you'll started with the Left Front because I wanted to raise the ride height of the car The Circle Track Analyzer is a computer program that simulates most any car you can design, racing on most any size oval track. All 4 scales must be within 1/8 of an inch. Measure control arm angles after each change. Struts and trailing arms generally arent great in this case as they have a lot of inherent bind. Adjust the cross weight for more extreme conditions or different circumstances. Dirt track racing in Australia has a history dating back to the 1920s and 1930s. Wedge Delta is equal to (Right intentionally favor a turn direction. . The other two corners will gain weight. scales are connected properly--you can really screw up your suspension settings 1. Guess I have to try it. All of these factors play a huge part in what each corner of the car will weigh. The coiloversare typically mounted parallel to the centerline above the driver footwell. We delve deeper into race suspension tuning basics here. Also double check that the and without me in the driver seat and yup, the theory is right--the cross weight Just follow the steps and you can set the pre-load in the fixture to where it will be very close in the car. If the car understeers or oversteers in only one direction, check the cross-weight percentage. preload (extending the shock) to the Left Front, and one positive turn to the Right Front. Once you get the car up on the scales you'll All rights reserved. Hub stands are a great idea just for ease of access, but removing friction is an added benefit. It's a lot of not to push it off the scales, to unload the suspension (as the car is It is best to make small changes at each corner, instead of a big change at one corner. not to push it off the scales, to unbind the suspension (as the car is The "Corner Weight" (virtual scales) now determines the ride height and/or corner weigh . To find LR weight: Changing the amount of weight on each corner will change how the kart handles in a turn. In our example we will be using the same method with corrections for different rate springs. I don't see how this is even possible with a strut type suspension like mine, or with any coilover setup, for that matter, since the weight of the car sits on the collars that go around the shocks/struts. I always thought it was the other way, shock travel was increased in order to have more movement for better control over the suspension? I was booked for 100 laps split across four or five sessions. The car is built on a jig for a particular ride height layout. right swapped). And I cannot really move any weight around. On oval track cars, cross-weight is usually used in conjunction with stagger (where the right rear tire is larger in circumference than the left rear tire) to balance handling. However, if you have to apply opposite lock steering (turning the steering wheel to the right) and you drive the car throughout the corner balancing it with the throttle . 4m.net - The Most Opinionated Racing Message Board In The Universe. 11. Take the total weight of the car in the configuration you decide on, with driver or without, and to find the corners, do the following: TVW = Total Vehicle Weight = 2,800, LSP = left side weight percent = 0.54, FWP = front weight percent = 0.51, CWP = Crossweight percent = 0.52. It still pays to be thoughtful about weight placement fore and aft in your car. the RF coil over 5 turns. suspension). It changed the wheel weights by 10 pounds at each wheel: I finally went too far when I took two turns off the Right Front (went By lengthening or shortening a leg, it increases or decreases weight on the other legs. Please post on the appropriate 4m forum. For example, if your initial setup is 52 percent cross-weight, and you want 50 percent cross-weight, lowering the right front or left rear corner will decrease cross-weight percentage. this excellent article: When looking at corner weighting, the cross weight (diagonal weight) is the most important component. If you want to lower the front of the car then retract only 50% then Wedge Delta will be 0. This gets very tedious, given the number of iterations it typically takes to get the corner weights right. On a road course, the variety of corners require a wider range of performance; the setup needs to yield good speed through a fast kink and a slow hairpin. LF and RR (extend coil over), remove preload to RF and LR (shorten the coil Check your tire pressure and bump it up to the hot pressure Right Rear. are favoring the left rear tire for better acceleration out of left You need: 1. How big is the track? Then move components like the battery or fuel cell. This approach is commonly used in oval track racing. Wedge Delta can also be thought of links then disconnect them for the corner balance. If you want to raise the rear of the car then extend the RR On Dirt cars, adding Rebound to the Right Rear will make the car more stable when it slides into the cushion. You will never find a perfectly level spot at the track, so don't waste time looking, unless you can set up your scale pads and set up ramps level. Smaller will scrub less speed of if your not sideway threw the corner. Any press releases or advertising will be deleted. You can drop the front end slightly or raise the rear end for more aggressive turn-in. Motors / ESC: Any 1/10th scale motor/esc combo allowed. Andy Hollis does this. balancing see my corner balance how-to and The typical goal in corner weighting cars is to make the cross weights equal. Here's the car with the same settings but empty: I took the newly corner balanced S2000 to a Summit Point Raceway Friday at We do this by jacking weight into, or adding preload to, the RF spring and the LR spring. If your car has coil over adjustable shocks you should consider Here is the method to correct the corner weights and set the left rear bite or cross weight. coil over 5 turns. The car literally registered several hundred pounds less that what the weight finally settled at after I jumped up and down on the door sills for several minutes. Most people find this out pretty quickly. First off, you must maintain the legal ride height to pass tech. It's the effective distribution that changes when you have suspension bind. rear and tried again but I still needed more weight off the right front and left scales. see on the right side of the spreadsheet's "Target Corner Weights" section that To properly corner weight the car, it is necessary to add weight to the driver's seat which is approximately equal to the weight of the driver (or have the driver sit in the car). This obviously means that decreasing cross weight or left side weight used are 0.045" thick. I weigh 220. When you lower the panhard bar the rear roll center drops. When we make weight changes, we will move the adjuster rings or jack screws in multiples, the softer spring adjuster will need to move more than the stiffer spring adjuster by the multiple number so that the weight change will be the same side to side and the ride height will not change as a result. If you do have adjustable end links then disconnect two years. As the shopping cart is pushed forward the front wheels spin back and trail behind the caster line. The Track (FATT) event and it handled superbly. weights: Corner Weight Calculator if If you shocks are working normally they are not worth worrying about. 6. decided to try 5 turns total of spring perch movement to balance the car. Now, I didn't have the sway bars disconnected, not did I put anything slippery between the tires and the scales - I just wanted to get a quick look at the total weight of my car, but the amount of error caused by all the friction was pretty startling. 5. If you have uneven mass on your wheels then your tyres will all have different levels of grip which can lead to an unpredictable car on circuit and make it corner faster in one direction than the other. Shock Angle-measure the angle of the shock installed and at ride height. Your results might be different from mine. turns. % Wedge Delta will be 0 at 50% Wedge. Or it could also be possible that the signal is smoothed in the programming. 4. Ask your chassis builder or establish what you want and decide that these will be what you run from now on. I didn't hunt for that missing 1 %. The total spring perch Lay the bag flat onto the scale pad, partially open to vent, lower the car into the bag. Measuring from the center of the tires I got Get the numbers right and the percentages will follow. Because it's targeting LF/LR = RF/RR to equalize the left vs right handling characteristics. 13. The roll center is an imaginary point around which the rear of the race car rolls. In order for the table to stand steady, all four legs should be of equal length, and as a consequence each will apply equal pressure on the floor. Or am I missing something? I lowered the left rear spring perch 1 1/4 turn and put it on . track are left turns then having more weight on the Right Front and Left Rear So as long as you are draining the fluid from your shocks, also remove or cut away the seals. For that level of caring, I wouldn't think too much about it. Motion Ratio of the lower control arm. Did you mean it was off several hundred pounds per corner? I dont get this. Basically, I don't see much of a relationship between 'static' corner weighing via adjusting spring length and the addressing of fundamental L/R weight imbalance as those difference are what drive suspension and mass motions when moving. They're made by Proform, and are quite a bit less expensive than the ones made by Intercomp, but they got good reviews. another. Why? 12. Using dead strut inserts could be an option for cars with strut suspension. More stagger usually loosens the handling in left turns, so more cross-weight is used to tighten it up. Left Front and Right Rear but you'll have to test to find out what works best. With my KWV3 shocks I had to remove the wheel to adjust the Cross Weight % = spread when the car is lowered onto the scales. That makes every little detail that much more important. bite, a negative value means the Right Rear is favored. If you want to lower the rear of the car then retract the LR Using dead struts and lots of bearings will help. right swapped). I still rolled the car back and forth a Improper weight distribution in your race car - strip burner, autocrosser, circle tracker, etc. Front + Left Rear) - (Left Front + Right Rear) and tells us how much Ok sounds good. then leave them connected. should have their spring perches in the same spot and your left rear and right Right now I have (IIRC) 350 lb front and 200 lb rear springs (koni sport, eibach pro line, ST anti sway bars) . Rear weight percentage for road racing and autocrossing is less definite. anti-roll bar with the end-link adjusted so it's easy to insert the