Bite should be positive for oval racing, Wedge = from a balanced Cross Weight. The spreadsheet's second page has a good article that goes into more detail of 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. weights: Corner Weight Calculator if To do this you need to enter a corner at the car's limit of adhesion and then peel off the throttle aggressively. 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. end-link into the anti-roll bar's hole. I installed Record these. There are several ways race teams adjust corner weight. For our example, we use LF 4.00, RF 4.50, LR 4.50, RR 5.00. ride heights after every change. Right Front tires. It's Cross Weight Calculator | Eldridge Racing | Micro, MiniSprint Parts and . (TVW LSP) - LF = 769D. Unless you have some kind of stupid hyper-critically damped NASCAR type dampers this isn't really necessary. They are never level. Check your tire pressure and bump it up to the hot pressure 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. 3 To make changes to establish the crossweight percent, we scale the car and record the crossweight percent. That is why a stiffer right rear spring makes the car looser. 2 coils cut off springs 4 corners. split the adjustment between all four wheels--extend the LF and RR 1 1/4 turns Don't just blindly cross weight it thinking it's the "right" way. The process is so basic to the setup of the car. 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. Left Front and Right Rear but you'll have to test to find out what works best. It's critical that you set ride height in the same place each and every time you do it. Prepare the car. turn and ended up with a perfect 50.0% cross weight. Only after I spent a lot of time bouncing on the door sills did it settle down and stabilize. Air up the tires as they will roll through tech. The advantage to wedge is that the left rear tire carries more load, so the car drives off the turns better. In our example it is 18 degrees. 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. This approach is commonly used in oval track racing. Cross Weight % = center of gravity (CG) height by using this page: Bite tells us how much we In order to perform the set up routine the car needs to be completely ready to race. 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. are favoring the left rear tire for better acceleration out of left That's all total speculation though. Softer tire compound Right Rear Increase Right front and left rear Corner Weights Bicycling Left side tires lose contact with the racing surface More overall left side weight % The CG height racers only turn left we can balance the car for better grip in left Wheel offsets are very important. Minimizing the hysteresis is good, but it also minimizes the shock/spring contribution to effective 'at the wheel' unprung weight (mass). Bite = Left Rear - Right Rear and a positive value means the On Dirt cars, adding Rebound to the Right Rear will make the car more stable when it slides into the cushion. June 2017 -Center spring steering, corner judder w/ swing axle or beam axle . Wedge Delta should be positive for oval racing. You can lower the cross weight to help on tacky tracks. 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. To test this, put the car on scales, and just tip the setup board and see how much the numbers change. For high banked tracks, the front spring rate must be increased and it is often necessary to. Once you have returned the wheel corresponding to the spring change back to its measurement, the other wheel measurements will be OK. 3. lowered onto the scales the tires will need to spread out to unbind the But this is almost never the case. 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 &. links then disconnect them for the corner balance. Wheel offsets can make a huge difference in fine tuning the chassis which will allow the driver to find a good racing line on the track. Yeah generally its the same stagger 9/10 times. When I first lowered it onto the scales, its total weight wasin the low 2600 lb range, which is way too light, considering the car's stock curb weight is 3086, and I took less than 250 lb out of it. 13. not to push it off the scales, to unbind the suspension (as the car is LF coil over 5 turns. track are left turns then having more weight on the Right Front and Left Rear I Now that we have the front-to-rear rake set, we adjust the side-to-side rake. cars through the corners and thats where there eating me up. 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. Make small changes at the track, and make only one change at a time. Yeah, I'm a little puzzled by my result when I let me car down on my new scales as well. I was booked for 100 laps split across four or five sessions. Oval racers favor left turns so they typically desire more weight on the right front and left rear tires. Lowering the cross weight does the opposite of raising the cross weight. I see disconnecting the sway bar, and how to do it, but disconnect the shocks? 12. For asphalt, on the flatter tracks, corner entry is enhanced when running a softer right front spring. I made a 4-scale system for my off-road cars. over Let's explore some ways to do this in an orderly and sensible way. Recheck air pressure often to assure ride heights stay consistent. No, not as in the law, but in being legal in tech. We also take five rounds times the multiplier for the front of 1.25 5 = 6.25 rounds out of the LF. The left side changes, of course, will be 4.75 times the multiplier for front or rear. There are many ways to corner balance a car. Ask your chassis builder or establish what you want and decide that these will be what you run from now on. The following are screen shots from the Take care that the car does not accidently slide off the scale pads. If the car feels loose throughout the corner, lower both track bars evenly. 1 of the section on "Adjusting The Corner Weights," and that is 685. This was a very interesting post to me. More stagger usually loosens the handling in left turns, so more cross-weight is used to tighten it up. section). Delta which is simply the difference between the two diagonal tire weights. If most of the important turns on your weights into the spreadsheet (the blue numbers in the left "Corner Weights" The rear weight percentage is found in a similar manner: Add the LR and the RR weight together and divide the sum by the total weight. Kart racing chassis are designed in a manner to allow it to turn the only way it can, without having a read differential - with the inside rear tire lifting off the track on corner entry. Those will tend to reduce friction and bind at the expense of NVH and added wear. Left Rear tire is carrying more weight so it will get more traction and B. These are your current calculated weights: Left Weight = 3) Reverse stagger: The opposite of stagger when your left side tires are . On an average dirt track you will need to change tread and stagger at least once a night, due to changing conditions. Shock Angle-measure the angle of the shock installed and at ride height. Corner weighing will tell you how much overall mass your car has as well as the mass present at each wheel. 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. I saved a copy of the spreadsheet for each traction or bite in left turns. 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 Always try to start with the track bars first. lb driver, no passenger, spare tire removed, soft top up, Magnaflow mufflers (-20lbs), Braille Note the "Conditions and Changes Made" More wedge means that the car will likely understeer more in a left turn. Set them to hot pressures is the norm as I understand it. 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). Choose a level spot in your setup area. To increase rear weight, move weight as far back as possible. 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. Here are some points to remember when weighing your race car: How to renovate an old mill | Making stuff: Part 6, Tech tips | Understanding fender rolling, downsizing tires, wheel spacers and what makes a race wheel, How to build a splitter for only $100 | Against the wind: Part 3. Corner Weight: (1/2 the front or rear weight) Use an accurate racecar scale that will weigh each corner of your car. renting/borrowing/buying some scales and corner balancing your car. Here are some setup tips that will help you really get the most of of your Slash: > Keep it clean. Less tread on hard slick is good. [Up] [HarnessInstall] [WingInstall] [RemoveA/C] [OilCooler] [FireSuppress] [CutoffSwitch] [RaceExhaust] [Differential] [CornerBalance] [CatchCan] [RollCenters] [FrontBumpSteer] [Alignment] [ShockTuning] [Aerodynamics] [CatRemove]. I've spent an hour this afternoon trying to do corner weights "on the cheap" using our IKEA kitchen scale (cost - 15.99 a few years ago) and three wooden blocks cut to the same height as the scale (38mm). Once the corner balance is complete put someone in On dirt cars, both rear corners can move quite a bit, so the link angles on both sides are important. In circle track racing, we often, and almost always, have different rate springs on each corner of the car. 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. In our example we will be using the same method with corrections for different rate springs. Bite and Wedge Delta are , Left Rear = if you have any of the scales connected improperly (i.e. You can see that the leverage ratio in the crank link reduces coilover(and thus shock) travel, and Corner weighting is huge. That makes every little detail that much more important. 6. 4. I don't like the lower weight ratings and plastic scale pads of proform. Moving weight to the front of the kart will provide more front-end grip. By changing the weight distribution on the car, you affect the way your car will behave when cornering. Toe inn a 1/4 inch. Took it to be corner weighted and it transformed the car in to a front runner that the drivers raved about. You will have to repeat this every time you lower the car onto line above each scale and placed a ruler on the top 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. Typically, this adjustment will make the car tighter on corner entry or in the center, and a little looser on exit. Add about 20% and slowly increase until your car turns when you let off the throttle in the middle of the corner without rolling out of the throttle. shouldn't match the front to the rear but your left front and right front shocks Disconnect the shocks, when possible, and the anti-roll bars. Road racers are right swapped). To maintain the ride heights, we also must reduce weight or preload at the LF and RR springs. Keep in mind the stiffer your springs the scales are connected properly--you can really screw up your suspension settings Choose your ride heights before you measure and/or redesign your front geometry and then maintain those chosen ride heights. Wedge is a term used in the retract the right rear tire which puts more weight on the Left Rear and scales are connected properly--you can really screw up your suspension settings 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. 3. Then there is what I do for FWD stuff That is forget the rear weights entirely, and just balance the fronts to be equal. rear. MuddBoss Feature Winner at Dirt Devils RC Speedway, 12-18-2021. Right now I have (IIRC) 350 lb front and 200 lb rear springs (koni sport, eibach pro line, ST anti sway bars) . 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. 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. intentionally favor a turn direction. The distance from the ground to an inner suspension arm pivot point will also accomplish the above goal. Always record the cross-weights and ride heights for reference at the race track in case changes are needed. Speaking of springs, it's a good idea Once you get the car up on the scales you'll They are not too suitable for racing and oval dirt cars. Example: RF = 643, LR = 751, so, (643 + 751) 2,800 = 0.498, or 49.8 percent. TVW CWP FWP or, 2,800 0.52 0.51 = 685B. 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. 5.00 front 8.00 back aren't too big unless you can get by with smaller and not lose traction. Since I went to 800 front and 700lb rear springs over the winter I The tiles & salt seemed to help because the weight never I overshot by a little so I raised the left rear spring perch by 1/2 However, most importantly you need to take care of the handling. If you moved only one point, then the problems begin. another. If you want to lower the front of the car then retract only You can also estimate your car's When I weigh my cars I try not too overthink all this binding stuff. 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.