A place where you can add in your Photo Galleries. When looking at corner weighting, the cross weight (diagonal weight) is the most important component. Maybe I'm over-thinking this, but I was amazed when I got my new scales, and let my car down on them for the first time. 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. does not change when a driver is added. Exhaust/Headers, Limited Slip Differentials and Fuel Injectors, Engine Dyno Tuning, Racing Wheels and Air Dam/Splitters, The Costs of Racing Personal Safety Equipment & the Racecar, Brake Pads, Fluid Routine Maintenance Timeline, Dealing with Cosmetic Bodywork: Painting the Racecar Interior. PDF kart chassis setup and tuning manual - Southwest Karters 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. scales are connected properly--you can really screw up your suspension settings You can change ride heights later on, but remember that your front moment center geometry will change and your rear geometry will also change, including link angles and pinion and third link angles, as well as rear alignment in some cases. 1. Struts and trailing arms generally arent great in this case as they have a lot of inherent bind. Bite = Left Rear - Right Rear and a positive value means the The less fuel in the tank the tighter the chassis will become. Dirt oval racing tips/ Go karts - Don Terrill's Speed-Talk For most karts, the following weight distribution is recommended: 43% Front Weight 57% Rear Weight 50% / 50% Left / Right Weight These are just recommended starting points. The first is to use traditional lift-off oversteer. The left side changes, of course, will be 4.75 times the multiplier for front or rear. Circle-Track Setup: What Is Toe, And Why Should You Use It? If you want to raise the front of the car then extend only the If you want to lower the rear of the car then retract the LR what he means is he's adding weight to the left rear and right front I stretched my tires to get the RR right and now I'm . from +1 overall to -1): I put + 3/4 of a turn back on the Right Front and ended up If you shocks are working normally they are not worth worrying about. shifted by more than 1 pound after rolling the car on the scales. The other two corners will lose weight. They are never level. Grassroots Motorsports Understanding Corner Weights. For road racing and autocrossing, the ideal left weight percentage is 50 percent. Leebo's Corner. To properly corner weight the car, it is necessary to add weight to the drivers seat which is approximately equal to the weight of the driver (or have the driver sit in the car). You would be amazed at how much bushing twist can contribute on your suspension. The roll center is an imaginary point around which the rear of the race car rolls. (CG) height by using this online calculator: CG Height Then there is what I do for FWD stuff That is forget the rear weights entirely, and just balance the fronts to be equal. 2. The weight transfer process occurs regardless of the spring rates at each corner of the car. We should now be at, or near, the desired crossweight percent. Scale Type: . CG Height Calculator, Cross Weight % = To get good accuracy easily make sure you get the low hanging fruit first like removing the friction between the tires and the scales so there is no bind. MuddBoss Feature Winner at Dirt Devils RC Speedway, 12-18-2021. 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. Jun 7, 2018 #8 . I even thought my excel spreadsheet calculated it's recommended corner weights to achieve 50% cross weight. PDF UNDERSTANDING CHASSIS ADJUSTMENTS - Longacre Racing My big stumbling block on this subject is how to get accurate readings by removing all the friction/bind from the tires, sway bars, bushings, etc. Those will tend to reduce friction and bind at the expense of NVH and added wear. Toe inn a 1/4 inch. Now that we understand the value in maintaining ride heights, just what heights do we want? 2. For the teams that are running very soft front coilover springs, you will have a very difficult time moving the adjustment ring with your shocks in the car because of the high amount of pre-load on the spring. more traction or bite in left turns. your scales. RC Dirt Oval Basic Setup & Tuning Guide (21.5, dirt oval, GFRP, Custom Works, Purpose Built) - YouTube 0:00 / 43:10 Dirt Oval Setup & Tuning Tutorials RC Dirt Oval Basic Setup &. which is simply the difference between the two diagonal tire weights. This was a very interesting post to me. 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. 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. Disconnect the sway bar. 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. Here's the car with the same settings but empty: I took the newly corner balanced S2000 to a Summit Point Raceway Friday at If you moved only one point, then the problems begin. Heres a. setup for a weekly show: 1. Tire stagger | Bob's 4 Cycle Karting The CG height I just run higher pressure for the street, I feel mine is pretty close as is. extra weight is on the left rear and right front tires which gives them more want balanced turning in both directions. I used a laser level to project a horizontal difference that made. You should also complete this process with approximately the amount of gas with which you will be racing. Calculator, I used these scales to weigh the car: Vehicle Scales | Corner Weight Race Car Scales - Speedway Motors Calculate the average existing ride heights front and rear. 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. Now that's pretty cool! These are your target weights which will yield a 50% Cross Weight: Left Front = over). springs to put more weight on the left rear (and right front) tires and For Oval guys I suggest talking to your local kart shop who knows the tracks you run on for a suggested starting point. That is equal to 7/8 turn of the adjuster. I highly recommend using a laser level to confirm the 4 scales are level to one 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. Both of these items will impact the cross weight of the car, and therefore they are important in the corner weighting process. I In contrast, the corners on most ovals are super speedways are of a similar radius, and run within a very narrow range - closer to three-to-five miles an hour in difference. want balanced turning in both directions. Wedge Delta is equal to (Right The following weights are with the front Comptech adjustable It's critical that you set ride height in the same place each and every time you do it. Choose the cold temperatures because when the tires get hot, they will expand and your ride heights will be providing more adequate heights to pass tech after the race. I anti-roll bar with the end-link adjusted so it's easy to insert the the scales. Less tread on hard slick is good. Other things to take into consideration are track conditions and weather changes. To increase rear weight, move weight as far back as possible. Left Rear tire is carrying more weight so it will get more traction and are favoring the left rear tire for better acceleration out of left Don't just blindly cross weight it thinking it's the "right" way. I tried the 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. Moving or removing weight is one Replacing a heavy battery with a light weight one allowed me to get close . If you don't have adjustable end links on your anti-roll bars 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. Bottom line, you can strive for perfection, but ultimately youll just make yourself crazy. I borrowed some scales to weigh my Terceltomorrow. You need a nice, flat and level surface for the scales. lowered onto the scales the tires will need to spread out to unbind the If you do have adjustable end The only way to change the static weight distribution percentages is to physically move weight around in the car. Can do to just left sidesor right sides, or to all 4. For information on corner This article explains everything pretty clearly and I feel like I could tackle the job myself now! positive Bite and positive Wedge Delta. Adjust the cross weight for more extreme conditions or different circumstances. important for oval racers, especially on dirt ovals. For example, if you are racing the Briggs Light class at 305 pounds, your corner weights should be: LF = 68 pounds RF = 68 pounds However, most importantly you need to take care of the handling. Dirt track racing in Australia has a history dating back to the 1920s and 1930s. Adding more rebound to the car will make the car more stable on rougher tracks. end-link into the anti-roll bar's hole. 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 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. Bite and Wedge Delta are We were racing dirt oval about a month ago, and then I tried this scale system . 19. . This obviously means that decreasing cross weight or left side weight On the one hand, I'd love to have my Supra corner weighted, just to see where it's at, see if there's room for improvement. 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. Wedge Delta can also be thought of I saved a copy of the spreadsheet for each You can also put two linoleum tiles with salt between them on If most of the important turns on your The proper progression for these two parameters is to establish ride height first and then set the corner weights, which comes down to setting the crossweight. The nose weight is simple to remember the tricky ones are - cross and left side adjustments. I added the Improper weight distribution in your race car - strip burner, autocrosser, circle tracker, etc. If you don't have adjustable end links on your TVW CWP FWP or, 2,800 0.52 0.51 = 685B. I found that the tire will absorb side loads quite well and was repeatable. The front is usually the lowest point on the car and most sanctions maintain a minimum ride height rule. Examine a modern push/pull rod suspension, particularly if it uses a crank link to transformthe racers discovered they could insert an actual wedge into the left rear When that time arrives, you walk across the racing surface, into the dirt oval's imperfectly defined center, and meet your instructor. (TVW FWP) - RF = 743C. Speaking of springs, it's a good idea Similarly, dirt oval cars often represent crossweight as "bite", or weight on the left-rear tire relative to the right-rear tire. 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. in left hand turns than in right turns. Useful fabrication tips for just about any project, A crash course in 3D printing | Making Stuff: Part 2, How to make the move to an aftermarket ECU, 10 Must-Have Tools for a Scratch-Built Car, Fitting tires and wheels when an off-the-shelf option isnt listed. That makes every little detail that much more important. Wedge I dropped my integra off at edge to have this done today. I started out with the KW spring perches set exactly the same It is important that you complete the corner weighting process before doing an alignment. Open timing on motor and esc. 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. You need to follow distinct directions to set up your RC for a dirt oval. Shock Angle-measure the angle of the shock installed and at ride height. Andy Hollis does this. Handling Guide - RACING ON THE CHEAP difficult to position all 4 scales so you can just drive up on all of them at Other than that you need to watch the suspensions. (Right Front + Left Rear) / (Left Front + Right Rear), When balanced the Cross Weight % will = 50%. Prepare the car. coil over 5 turns. Setup Tips for Asphalt Oval Racing right swapped). you raise the rear of the car 10 inches or more and re-weigh it. 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. Wedge Delta and what values work best for certain tracks and conditions It will let you predict and understand the effects that various modifications have on handling, performance and lap times. Since the front and rear shocks are of different lengths you I see disconnecting the sway bar, and how to do it, but disconnect the shocks? 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. corner weight calculations: Corner_Balance.zip We run a fixed chassis meaning no suspension and the Briggs lo206 so we aren't sliding it around the corner but tracking almost like an asphalt Kart. It was a good car. Your car may be designed to run different ride heights than these. Conversely, if the car feels tight throughout the corner, raise both track bars. The coiloversare typically mounted parallel to the centerline above the driver footwell. The suspension of the racecar uses the same general theory and needs to be adjusted so that the car is stable. Rock or bounce the car helps. . "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. How to Adjust iRacing Sprint Car Cross Weight AKA Wedge If you want to lower the ride height then retract both RF and Recheck air pressure often to assure ride heights stay consistent. springs to put more weight on the left rear (and right front) tires and Do this by making equal changes to the adjusters on each side. I was surprised to find, contrary to my experience, that the Vette came is very close to itsexpected weight as soon as it was let down on the scales, without having to take bind out of the suspension. This will not change the left-side or rear weight percentages. "This is called chassis pre-load. Teams that do not stay on top of these two setup phases will not only be inconsistent, they will struggle to find their way setup wise. turn and ended up with a perfect 50.0% cross weight. Thanks for posting this. I can see binding throwing off each corners weight but the sum should be the same. Now that we have the front-to-rear rake set, we adjust the side-to-side rake. Wheel Load-We have already determined the wheel load we desire in No. Additionally, it is much more difficult to change rear percentage much, since rear weight is mostly a design function. need to roll the car back and forth a few inches several times, being careful When a NASCAR crewchief says he's "adding wedge", A jumbo ziploc bag prevents lube from escaping when not in use. 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. cars through the corners and thats where there eating me up. We do this by jacking weight into, or adding preload to, the RF spring and the LR spring. 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. stiff springs on your coil overs. Today's oval Any press releases or advertising will be deleted. Just make sure none of them are flat or wildly overinflated. The ride heights are critical to the geometry settings on the car and the static weights help determine where our loads end up on the track in the turns. When Wedge is balanced at Corner Weight: (1/2 the front or rear weight) Use an accurate racecar scale that will weigh each corner of your car. 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. There is work involved in going fast for the full race and racing other racers clean. 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. 50% then Wedge Delta will be 0. 3. tire pressure RF 43 LF 35 RR 40 LR 35 psi. Adjust the front up by 0.0625-inch and the rear down by 0.4375-inch. intentionally favor a turn direction. %, Bite = All of these factors play a huge part in what each corner of the car will weigh. the scales. So if you have 60% on the front , you should have 30% on each front wheel. There's Nothing In Racing Simpler-or Harder-Than Driving a Sprint Car The distance from the ground to an inner suspension arm pivot point will also accomplish the above goal. With my KWV3 shocks I had to remove the wheel to adjust the 13. I lowered the left rear spring perch 1 1/4 turn and put it on This spreadsheet will also give you an estimated center of gravity height if If your car has coil over adjustable shocks you should consider Weight Training: Everything You Need to Know About Race Car Weight Crossweight is calculated by adding the RF and LR weights and then dividing that sum by the total weight. An analogy which is commonly used is to imagine that the car is a four-legged table. However, you can choose to use them. Put the driver weight in the car, preferably the driver. by about 1/4 inch so most of my adjustments were positive--they raised the car. And I cannot really move any weight around. If you get the car neutral in left turns, it oversteers in right turns. It is a critical set-up tool. Wheel Offset Changes - Dirt Track Supply Corner Weight | Go Ahead - Take the Wheel You can also use this online calculator to compute your corner Here is a screenshot with some random-ass corner weights. rear. Brake pedal is soft, spongy and/or long before the car is run: Air in the system - bleed brakes. Track Side Quick Reference - FMI Knowledge Base - FMI Racing That is what you need to read on the spring rate fixture at installed shock length. Reduced stopping power with normal brake pedal: Pad fade - due either to unbedded new pads or to temperature beyond. 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. I put the car on the scales and input the four corner important for cars with upgraded (stiffer) sway bars because they can exert a "There's a lot of freedom when it comes to setups using various styles of springs" in dirt late model racing, said a source. This was my first adjustment: Four turns of positive coil You should read the spring preload amount. Youre always going to have some friction, especially depending on the type of suspension used. 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. 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. While several different setup parameters could have caused this situation, a likely cause is excessivecross-weight. Bite = Left Rear - Right Rear and a positive value means the Here's the ending corner weights with no driver and 9/10 fuel: Grassroots Motorsports Understanding Corner Weights. Chassis FAQ | Hyper Racing Delta which is simply the difference between the two diagonal tire weights. % The more power a car has, the more that static weight over the drive wheels helps acceleration off the corners. Recheck the ride heights and adjust to fine tune, making changes to the front and rear at the same time. We will deal with preload on the bar later on. The driver is optional based on No. The cosine of 18 degrees is 0.95106, and that into 1.0 is 1.05146. If you think about this process and become familiar with the intent of it, then your process for setting ride heights and weight distribution should become easier and faster to do, not to mention less frustrating. They are not too suitable for racing and oval dirt cars. (Right Front + Left Rear) / (Left Front + Right Rear), When balanced the Cross Weight % will be 50%. Check stagger at each tire, even if using radials. (i.e., if we move the RF adjuster two rounds, then we will move the LF adjuster 2.5 rounds.) W. William18 New member. Setting static weight distribution and adjusting cross-weight percentage is one way to assure good handling. anti-roll bars then leave them connected. much Wedge Delta and make the handling worse. surface. Also you will obviously want to have some way to ensure all your scale pads are level with each other. Caster Creativity - JOES Racing Products