Some engines are used in two different classes with the only change being exhaust system. When dealing with advanced suspension tuning, some people may adjust the corner weights in a manner to impact the way the car handles based on the tracks layout. extra weight is on the left rear and right front tires which gives them If you're setting up a FWD race car, and you can see this in historical VW Golf or original Minis, they often lift and inside rear-wheel. Now that we understand why we need to maintain a set ride height, let's go through an example of how to set ride height. Granted, moment centers will stay fairly consistent with small movements of the chassis in dive and roll from the ride heights being off a little. When you adjust your coil overs I used a laser level to project a horizontal Carry some in your tool kit and buy tarus wheel studs if you want a dirt cheap slightly longer wheel stud to have more safety. Corner weighting your car is center of gravity (CG) height by using this page: (i.e., if we move the RF adjuster two rounds, then we will move the LF adjuster 2.5 rounds.) Ask your chassis builder or establish what you want and decide that these will be what you run from now on. anti-roll bar with the end-link adjusted so it's easy to insert the Calculate the spring rate multiples. Of course you can add too 6. . be appropriate such as making small adjustments to all 4 wheels--add preload to With an oval track car turning to the left, weight will transfer from the inside to the outside. So we multiply the difference, or 4.2 percent, by 1.12 and we get 4.7 rounds of right side change to the spring pre-load, or 43/4 rounds. With my KWV3 shocks I had to remove the wheel to adjust the As long as the tires have near "1 to 1 traction" with the ground, you should set up your race car like an asphalt car (see the Chassis Set-up At The Rear For Cornering page). Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. height and corner balance new springs. will help with those turns. If you want to lower the front of the car then retract only . When a NASCAR crewchief says he's "adding wedge", corner weight calculations: Corner_Balance.zip Disconnect the sway bar. 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. 3 To make changes to establish the crossweight percent, we scale the car and record the crossweight percent. It would just automatically settle. You can lower the cross weight to help on tacky tracks. the front ramps then jack up the rear and lower it onto the rear scales. used cheap linoleum tiles (49 cents each at Home Depot) to shim two of my scales And what do you mean by "lots of bearings"? Ideal weight percentages: Front - 43-45% Left - 53-56% Cross - 52-54% What do these numbers mean? Brake pads badly taper worn - replace. On the other hand, it drives really, REALLY good for being setup by this idiot behind the keyboard, and I really don't wanna spoil a good setup by chasing after a perfect setup at least not yet. W. William18 New member. These are your current calculated weights: Left Weight = Do these percentages apply for front wheel drive cars? (I suppose cooking oil, motor oil, KY, or Astro-Glide would also work). Measuring from the center of the tires I got I This spreadsheet will also give you an estimated center of gravity height if You would be amazed at how much bushing twist can contribute on your suspension. The typical goal in corner weighting cars is to make the cross weights equal. As for setting the left side and right side equal, I understandthe reason why it might be best, but hard for me to picture how to adjust it. What you're saying makes sense, but I can't explain why it took so long for my car to settle into its final weight reading. Rock or bounce the car helps. to balance your car in one big step. The vanilla neon setup would be SDK suspension (stock ACR, look at neon.org and figure out what you have) with 3.5 deg front camber, 1 to 1.5 rear, zero to 1/8" in toe front and rear. When Wedge is balanced at Use those racing internet forums, and dont be timid about asking for some assistance! Just to confirm the theory I checked the corner weights with I painstakingly leveled the scales and marked their locations Open timing on motor and esc. There is work involved in going fast for the full race and racing other racers clean. difference that made. Right Front tires. Here is a screenshot with some random-ass corner weights. Less fuel equals faster speeds. two years. I always thought it was the other way, shock travel was increased in order to have more movement for better control over the suspension? This adds pressure to that end of the car just like putting the paper wedge underneath the table leg. So, ride heights in the front are more critical for maintaining camber angles. Here's the ending corner weights with no driver and 9/10 fuel: Grassroots Motorsports Understanding Corner Weights. Check stagger at each tire, even if using radials. The problem with this option is simply that hub stands aren't cheap - the lowest priced ones I've found are $849, kind of a lot of money for something most people wouldn'tdo all that often. 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. Would be interesting to see how close to ideal I got it though, given how well it handles already. if you have any of the scales connected improperly (i.e. If the car feels loose throughout the corner, lower both track bars evenly. you run on the track. Calculate the rear weight bias by adding the rear weight (LR and RR) of the chassis and dividing it by the total weight of the chassis (LF + RF + LR + RR). The same thing happens with a race car. Compressing the spring of a left-rear wheel or adding wedge puts more of the car's weight on that corner. You will need to weight your vehicle on each tire to use this tool. Corner balancing, sometimes referred to as "corner weighting," Basically so long as I don't completely overcook a corner entry, it does better than any car this heavy has any right to Good stuff. Smaller will scrub less speed of if your not sideway threw the corner. want balanced turning in both directions. It is best to make small changes at each corner, instead of a big change at one corner. Right Rear. They are never level. You've tried springs, shocks, different bars, neutralizing the anti-roll bar, and nothing seems to work. Other than that you need to watch the suspensions. Guess I have to try it. Most chassis manufacturers will tell you what ride heights are best for their cars. In order to perform the set up routine the car needs to be completely ready to race. links then disconnect them for the corner balance. supposed to. box in the "Ride Height" section of each spreadsheet. It puts power down better, and any decent FWD car will be carrying a wheel in the air around a turn anyway, so by default the outside rear gets 100% weight transfer when it's being asked to turn anyway. (adsbygoogle = window.adsbygoogle || []).push({}); If you prefer Microsoft Excel a Corner Weight spreadsheet is available for download here coil over 5 turns. 4. scales. Any press releases or advertising will be deleted. bite, a negative value means the Right Rear is favored. Make sure the vehicle is loaded with driver, passenger, and cargo just like you will drive it or . All of these factors play a huge part in what each corner of the car will weigh. On an average workbench/table that's close to level, it's probably < 3g difference per corner, which is within the tolerance of stiction / binding in a touring car. It was a good car. 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. 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. With the driver weight, the left side might move down 1/4-inch and the right side down 1/8-inch. I For information on corner At least for road racing. to get the desired corner weights your ride height will change. I use 2x6 wood planks as ramps to drive the car onto By changing the weight distribution on the car, you affect the way your car will behave when cornering. The front is usually the lowest point on the car and most sanctions maintain a minimum ride height rule. If you moved only one point, then the problems begin. Adjust the rear down by using the same method as in No. Front + Left Rear) - (Left Front + Right Rear) and tells us how much pounds of preload to the scale weights. I was booked for 100 laps split across four or five sessions. balance is complete put someone in the driver seat and reconnect the To favor right turns, put more weight on the Race Classes Whats Available and Acquiring a Racecar, Suspension, Glass Sunroof Replacement and Racing Seat and Harnesses, Fire System, Transponder, Rear View Mirror. You're better off not corner balancing the car than doing it on an unlevel unbalanced--it will turn better in one direction than in the other (all other To favor right turns, put more weight on the So we turn the RF adjuster up (to lower that corner) 2.5 turns and the LF down (to raise that corner) 2.5 turns. Also you will obviously want to have some way to ensure all your scale pads are level with each other. More wedge means that the car will likely understeer more in a left turn. racers discovered they could insert an actual wedge into the left rear In my situation, I have a lift, and I'd like to simply drop my car onto the scales, but it seems like that's the worst option as far as removing friction and bind. 10. Funny. Bounce the car at each corner to free the suspension from any bind, then roll the car onto the scales. On a road course, the cross-weight percentage should be very close to 50 percent, within a half-degree either way, to keep the handling balance similar in a right-hand turn compared to a left-hand turn. I even thought my excel spreadsheet calculated it's recommended corner weights to achieve 50% cross weight. If most of the important turns on your Once you have returned the wheel corresponding to the spring change back to its measurement, the other wheel measurements will be OK. 3. In our example we will be using the same method with corrections for different rate springs. Wedge Delta can also be thought of front left and That is equal to 7/8 turn of the adjuster. The car is built on a jig for a particular ride height layout. typically not concerned with bite and wedge delta because they usually of the scale to take a reading. Astrut with its innards removed? I gave up on running adjustable end links on Examine a modern push/pull rod suspension, particularly if it uses a crank link to transformthe started with the Left Front because I wanted to raise the ride height of the car Right Front tires. I was surprised how much these high rate It still pays to be thoughtful about weight placement fore and aft in your car. 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. It's always possible that there's something wrong with my scales - I'll call their manufacturer and get their input an recommendations, and I'll let everybody know what they say. 13. And since the necessary scales to complete this process cost in excess of $1,000, I suggest you have the corner weighting done by finding another club racer in your area who has (or knows someone with) access to scales and would be willing to help you. 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. For a car with a 17.5-inch lower control arm length and a ball joint-to-spring mount distance of 2.5 inches, you divide 17.5 by 15 (17.5-2.5) to get 1.1667 and then multiply that by itself to get 1.3611. A common example of caster is a shopping cart. All 4 scales must be within 1/8 of an inch. Corner weighting is huge. For pure race cars this isnt a consideration. intentionally favor a turn direction. and Left Rear. Here's a box stock 2006 Honda S2000 with 5/8 of a 5.00 front 8.00 back aren't too big unless you can get by with smaller and not lose traction. then set corner weights and cross weight. much Wedge Delta and make the handling worse. in the driver's seat to load the suspension. important for oval racers, especially on dirt ovals. Your results might be different from mine. I lowered the left rear spring perch 1 1/4 turn and put it on Get the numbers right and the percentages will follow. It is best to get 50 percent left-side weight when possible. can help us get our setup right with less testing. I'm off by 0.1% (see numbers on left side of the spreadsheet). Once static weight percentages are set, work on cross-weight percentages. that as a result the coil springs must bequite beefy and stout, 600 lb/in or more. You need: 1. split the adjustment between all four wheels--extend the LF and RR 1 1/4 turns Here are some setup tips that will help you really get the most of of your Slash: > Keep it clean. And actually you'rereally not going to changefront/rear weight balance with ride height changes, so itreally only matters that pressures are even side to side. MuddBoss Feature Winner at Dirt Devils RC Speedway, 12-18-2021. over want balanced turning in both directions. works well. This article explains everything pretty clearly and I feel like I could tackle the job myself now! track are left turns then having more weight on the Right Front and Left Rear If you had a car with a fully rod-ended out suspension that frictionless and frictionless tires you wouldn't need to roll the car around or bounce it or anything. A place where you can add in your Photo Galleries. Thinking about this a little, the weight measured by the scales is the sum of the force of gravity acting on the car's mass, and the force of the springs pressing downward. Typically, this adjustment will make the car tighter on corner entry or in the center, and a little looser on exit. (TVW FWP) - RF = 743C. used are 0.045" thick. turning the front wheels to measure caster. 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. When I drive down a strait road the I can clearly feel that the drivers side is heavier over bumps expansion joints and dips and the like. Multiply the wheel load of 685 times the motion ratio squared, 1.3611 times the shock angle cosine squared of 1.1056 and we get 1,030.8 pounds of spring preload. I recommend you start with your car at your desired ride left to right (measured with a digital caliper) and my ride height was pretty the scales. While several different setup parameters could have caused this situation, a likely cause is excessivecross-weight. Interested in hearing peoples' opinions and (preferably) experiences. cars through the corners and thats where there eating me up. We now take five rounds out of the RR and add five rounds times the rear multiplier, or 2.0 5 = 10 rounds to the LR. Heres a. setup for a weekly show: 1. Since each side at each end will usually have different rate springs, the amount we change the spring height adjusters will differ side to side. Grassroots Motorsports Understanding Corner Weights The SRM will determine the relative changes to the spring height adjusters for weight changes. more traction or bite in left turns. 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. Just make sure none of them are flat or wildly overinflated. but tend too love the 1/2 miles.I just cant figure out a way too get these. "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. If the driver lifts early but still has a fairly good amount of roll speed into the corner, there probably isn't much brake being used. the sway bars because they fail so often and the bars only added a couple of Hub stands are a great idea just for ease of access, but removing friction is an added benefit. You can see that the leverage ratio in the crank link reduces coilover(and thus shock) travel, and Iretighten them after I've made all my adjustments. Then if it's for a particular road course, you will find several seconds optimizing for select turns and throwing any of the above methods out the window A friend's Chump Car found 2 sec at VIR making it turn right better than left. The coiloversare typically mounted parallel to the centerline above the driver footwell. g) Oval track and road racers use slightly different vocabularies to describe the adjustments made to their cars and the effects these adjustments have on the car's handling. June 2017 -Center spring steering, corner judder w/ swing axle or beam axle . Wedge Move ballast first, since it's easier. 11. 50% then Wedge Delta will be 0. < Enter your corner weights in pounds or kilos and click 'Calculate'. 14. I had to do this with my truck. The roll center is an imaginary point around which the rear of the race car rolls. If we are talking of weighing a stock type vehicle, not a lot can be done since there are no adjustable parts. I race in a spec class, so everyone is using the same equipment. for the front and rear sway bars and installed them with my girl friend sitting Are they non-adjustable? Basically - after you finish the set up routine, the car goes in the hauler. right swapped). That math gives us a percentage number to . Even 1/8 inch difference will make a difference, especially if you have Most oval track speedways are similar to those in the US for car racing such as sprint cars, speedcars (midgets) and sedans, with most tracks generally around mile (402 m) to mile (536 m) in length. weights and percentages and generates target wheel weights to achieve a 50% To truly optimize your shocks, your overall suspension setup must be right, including ride height, camber, caster, toe, and the correct spring rates. To keep things clear I call this added LR/RF weight Wedge Front + Left Rear) - (Left Front + Right Rear) and tells us how much retract the right rear tire which puts more weight on the Left Rear and as Left Rear Bite + Right Front Bite. We will deal with preload on the bar later on. These tell us all we need to know about the setup relative to the weight distribution. rear should be the same. knew I needed to put the car on the scales. decided to try 5 turns total of spring perch movement to balance the car. 3. more important corner balancing becomes. from a balanced Cross Weight. Kind of like a person standing on a bathroom scale under a low ceiling, pressing on the ceiling with his hands with some constant force. Adding more rebound to the car will make the car more stable on rougher tracks. I Dirt Late Models. Put the car on ride height blocks without the shocks in the car and then measure the shock length from center of bolt to center of bolt. You should read the spring preload amount. 6 Check your ride heights and make small adjustments for ride height and crossweight percentage if need be to finalize your setup. At the right rear, a quarter-inch change in the height of the end of the link will change the angle and can make an asphalt car undriveable. How would you makesomething like that? turns. If you want to lower the ride height then retract both RF and Proforms are cheap scales. A set up plan will help you to build a race winning effort. Bearings, like sealed roller bearings,solid bushings, or spherical joints. For our example we use: LF 200, RF 250 - 250 200 = 1.25 multiplier for the front. If we subtract the existing ride heights from the desired, we have front low by 0.0625-inch and the rear high by 0.4375-inch. 3. I've read all the info before, in various places, but it's good to have a refresher. Left front weight + right rear weight = right front weight + left rear weight. much Wedge Delta and make the handling worse. So, deviating from those numbers will mean you have a design other than what was intended for the car. That is what you need to read on the spring rate fixture at installed shock length. Custom iRacing Setups and Paints for dirt oval and asphalt oval cars. To carry the wheel load, the spring must be compressed quite a bit. My track width with CE28 17" x 9" wheels 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. and stock rear sway bars connected. For now, we don't want the bar to influence the ride height or the weights we set later on. When I weigh my cars I try not too overthink all this binding stuff. ZJjtX0xiMzjbfb86GLC7qpXBkrSlFeSNVds8hGW514OXUKSxf6kBDIneIL3TzHQV. Shock Position 1. Most people find this out pretty quickly. Any corner weight adjustments that you make will impact the alignment of your car. Calculate the average front and rear desired ride heights. 2. That is why it gets tighter. It's critical that you set ride height in the same place each and every time you do it. intentionally favor a turn direction. Moving or removing weight is one Replacing a heavy battery with a light weight one allowed me to get close .