Example: RF = 643, LR = 751, so, (643 + 751) 2,800 = 0.498, or 49.8 percent. I'm anxious to see what Proform says about my experience. I've read all the info before, in various places, but it's good to have a refresher. Grassroots Motorsports Understanding Corner Weights This is the arm length divided by the distance from the shock mount to the inner pivot line, squared. Proforms are cheap scales. Rebound adjustments will allow you to alter your car to a corner entry condition without affecting corner exit or vice versa. You can also put two linoleum tiles with salt between them on If you don't have adjustable end links on your anti-roll bars I extra weight is on the left rear and right front tires which gives them more Here's how we find the multipliers. On an average dirt track you will need to change tread and stagger at least once a night, due to changing conditions. We do this by jacking weight into, or adding preload to, the RF spring and the LR spring. Right Front weight: Left Rear weight: We delve deeper into race suspension tuning basics here. You can also use this online calculator to compute your corner Well there is a bit more to it than that. Did you mean it was off several hundred pounds per corner? 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. My car has solid/spherical bushings everywhere, so there should be very little bind from them. The front will show close to 60%. 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. 11. the scales and zero them with no weight on them. I put the tiles on top of the scales. I'm off by 0.1% (see numbers on left side of the spreadsheet). 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 measure (literally). turns. to get them exactly level. Took it to be corner weighted and it transformed the car in to a front runner that the drivers raved about. So, deviating from those numbers will mean you have a design other than what was intended for the car. In almost all cases, the loss of cornering performance in one direction is greater than the gain in the other direction. "There's a lot of freedom when it comes to setups using various styles of springs" in dirt late model racing, said a source. racers discovered they could insert an actual wedge into the left rear If the car feels loose on corner entry, lower the left track bar. to balance your car in one big step. Put the driver weight in the car, preferably the driver. The following are screen shots from the For high banked tracks, the front spring rate must be increased and it is often necessary to. You can use rubber tires on very specific tracks and seasons. To make sure your spring changes don't upset your ride heights or crossweight percent, you need to mark your wheel spacing to the fenders. Intercomp SW500 EZ Weigh Scales. Battery: 2 cell lipo max Yeah generally its the same stagger 9/10 times. If the person reduces the force with which he's pressing against the ceiling, the weight read by the scales will decrease. 12. to get the desired corner weights your ride height will change. cars through the corners and thats where there eating me up. stiff springs on your coil overs. 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. 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. Caster creates stability as the geometry . I added the I sometimes watch in frustration as teams struggle to set the corner weights and ride heights on their cars. To do this, we add five rounds of pre-load to the RF. I commented on this to the youtubevideo on TIG welding, where they put their C5 Vette on scales and had a contest to guess the weight correctly, so I apologize for the duplicate posts. Just to confirm the theory I checked the corner weights with typically not concerned with bite and wedge delta because they usually 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. Here is the method to correct the corner weights and set the left rear bite or cross weight. To keep things clear I call this added LR/RF weight Wedge These weights are in ready to race form (including driver on board). 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. An analogy which is commonly used is to imagine that the car is a four-legged table. I painstakingly leveled the scales and marked their locations from a balanced Cross Weight. The new existing ride heights are LF 3.6875, RF 4.8125, LR 4.1875, RR 5.3125. You will have to repeat this every time you lower the car onto You should also complete this process with approximately the amount of gas with which you will be racing. , Left Rear = It varies with weight removal, added. This is for a race prepped 1984 Audi 4000 quattro(2375lbs. Changing the ride height at any corner will change the cross-weight percentage. Because we desire 52 percent, we will need to increase the crossweight percent. Choose a level spot in your setup area. While several different setup parameters could have caused this situation, a likely cause is excessivecross-weight. To do this you need to enter a corner at the car's limit of adhesion and then peel off the throttle aggressively. Bite and Wedge Delta are tank of gas, and no driver or passenger: Now here's the same stock S2000 with a 215lb driver in the seat: I was really surprised to see how far off the stock S2000 was This will pitch the vehicle's. Cross weights can be changed by making ride height adjustments to the coil-over suspension by either winding the lower spring platform up or down. The following weights are with the front Comptech adjustable I gave up on running adjustable end links on I usually mark an even inch and write that inch number on the tape. We will deal with preload on the bar later on. that as a result the coil springs must bequite beefy and stout, 600 lb/in or more. 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. what he means is he's adding weight to the left rear and right front B. used cheap linoleum tiles (49 cents each at Home Depot) to shim two of my scales Positive front toe (tires pointing in) generally is desirable on lightweight cars that don't have a lot of shifting weight, such as go-karts. 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. This was a very interesting post to me. I Bottom line, you can strive for perfection, but ultimately youll just make yourself crazy. 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. Jun 7, 2018 #5 . I put the car on the scales and input the four corner 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. center of gravity (CG) height by using this page: I had the same question. If most of the important turns on your balancing see my corner balance how-to and you run on the track. need to roll the car back and forth a few inches several times, being careful weights into the spreadsheet (the blue numbers in the left "Corner Weights" calipers. not to push it off the scales, to unload the suspension (as the car is box in the "Ride Height" section of each spreadsheet. Other than that you need to watch the suspensions. A lowered rear roll center promotes side bite at the rear which tends to tighten corner handling. You can racers add "wedge" by adjusting the right rear spring perch--they The typical goal in corner weighting cars is to make the cross weights equal. I didn't hunt for that missing 1 %. In order to perform the set up routine the car needs to be completely ready to race. To test this, put the car on scales, and just tip the setup board and see how much the numbers change. 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. Wedge Delta and what values work best for certain tracks and conditions Note your ride heights and Many electronic scales will perform the calculations for you. Today's oval Corner weighting can be a complicated process for you to complete without someone who is experienced helping you. You will need to weight your vehicle on each tire to use this tool. The only way to change static weight is to physically move weight or ballast in the car. Raising the rear end will also provide a little more on-power grip by keeping more weight directly above the rear tires during acceleration. The LF needs to go up 0.3125 and the RF needs to go down the same amount. Your car may be designed to run different ride heights than these. Excessive front toe in will make a car turn into a corner quicker, & may create a loose condition. Because it's targeting LF/LR = RF/RR to equalize the left vs right handling characteristics. MuddBoss Feature Winner at Dirt Devils RC Speedway, 12-18-2021. Remember that this is a sample car, so don't use these numbers, but do use this method. %Right Weight = They are not too suitable for racing and oval dirt cars. you raise the rear of the car 10 inches or more and re-weigh it. The coiloversare typically mounted parallel to the centerline above the driver footwell. And I cannot really move any weight around. Rock or bounce the car helps. 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. To favor right turns, put more weight on the lb driver, no passenger, spare tire removed, soft top up, Magnaflow mufflers (-20lbs), Braille Cross weighting is crap for road courses and only applies to turning one direction OR if the car is about 50/50 F/R weight to begin with. The design has the engine and transmission scooched over to the drivers side so the drivers side weighs more empty. Choose your ride heights before you measure and/or redesign your front geometry and then maintain those chosen ride heights. More wedge means that the car will likely understeer more in a left turn. It's just turning left 2 times per lap. Doing the multiplication to square that number, we get 1.1056. Get the numbers right and the percentages will follow. Always try to start with the track bars first. so the suspension can settle and unbind. Even on a track with mostly right-hand turns, the problem in the left-hand turns costs a lot of time. you don't use Microsoft Excel. This means the driver should be in the car, all fluids topped up, and the fuel load should be such that the car makes your minimum weight rule at the designated time-usually after a race. Disconnect the shocks, when possible, and the anti-roll bars. if you have any of the scales connected improperly (i.e. Move ballast first, since it's easier. you weigh and adjust. You can also use this technique when adjusting your alignment and Cross-weight is also called wedge: If the percentage is over 50 percent, the car has wedge; if below 50 percent, the car has reverse wedge. To increase rear weight, move weight as far back as possible. "weight jacking," or "scaling," involves adjusting the spring perches of a car Bite tells us how much we Bounce the car at each corner to free the suspension from any bind, then roll the car onto the scales. Find a fairly level spot and mark on the ground with duct tape or marker where the tires sit on the ground. 2 1/2 turns. 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. 4 Establish the exact weight change in percent that a given spring height change will make and record that number. Corner weighing will tell you how much overall mass your car has as well as the mass present at each wheel. difference that made. after this adjustment we still need to add 39lbs to the Left Front and Bite = Left Rear - Right Rear and a positive value means the cross weight. 57.5" front and 59.625" rear. weights and percentages and generates target wheel weights to achieve a 50% Custom iRacing Setups and Paints for dirt oval and asphalt oval cars. Record each spring rate. You need: 1. (TVW LSP) - LF = 769D. renting/borrowing/buying some scales and corner balancing your car. retract the right rear tire which puts more weight on the Left Rear and 13. 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. This approach is commonly used in oval track racing. April 2017 -Bracketing settings, 4WD high speed pavement vehicle. Do these percentages apply for front wheel drive cars? on the right front and left rear tires. Find the difference from the desired average ride heights. oval racing world and is simply another word for Cross Weight. 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. 2 coils cut off springs 4 corners. May 2017 -Dirt late model pinning RF & heavy axle tube. Reduced stopping power with normal brake pedal: Pad fade - due either to unbedded new pads or to temperature beyond. I have now added the ratios so I can visually see what's happening. as Left Rear Bite + Right Front Bite. Corner Weighting 5. Additionally, it is much more difficult to change rear percentage much, since rear weight is mostly a design function. important for cars with upgraded (stiffer) sway bars because they can exert a 2. 8 Read the ride heights as they exist. When looking at corner weighting, the cross weight (diagonal weight) is the most important component. Basically - after you finish the set up routine, the car goes in the hauler. Bite tells us how much we . oval racing world and is simply another word for Cross Weight. You will have to repeat this every time you lower the car onto If you align your car prior to doing the corner weights, it will be necessary to verify the alignment again after the corner weighting is completed. If a setup sheet read as "30 pounds of bite", there would be 30 pounds more weight on the left-rear than the right-rear. Set them to hot pressures is the norm as I understand it. I started out with the KW spring perches set exactly the same Road racers are The Track (FATT) event and it handled superbly. 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. Just make sure none of them are flat or wildly overinflated. I have a 96 civic with a d16/manual. Smaller will scrub less speed of if your not sideway threw the corner. the scales. I use 2x6 wood planks as ramps to drive the car onto Right Rear weight: < Enter your corner weights in pounds or kilos and click 'Calculate'. Make small changes at the track, and make only one change at a time. So let's study ride heights first. More stagger usually loosens the handling in left turns, so more cross-weight is used to tighten it up. end-link into the anti-roll bar's hole. Look at the car as a chair with a short leg, if you want it to turn equally well left and right aim for 50/50 diagonal. 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. The first is to use traditional lift-off oversteer. I plugged in a bunch of numbers into my calculator and it all checks out. Adjustable end links are more With the stock setup the car should have more grip Calculate the spring rate multiples. Now that we have established the ride heights, our weights could be anywhere. Right Front tires. At least for road racing. I noticed that the spreadsheet I'm using on the left of the picturesets my "target corner weights" to less than 50% (49.6%),why is that? for the front and rear sway bars and installed them with my girl friend sitting Avoids a mess on scale pads and tires,prevents dirt fromcontaminating lube. A set up plan will help you to build a race winning effort. 12. You would be amazed at how much bushing twist can contribute on your suspension. shouldn't match the front to the rear but your left front and right front shocks For street cars it certainly can be. and Left Rear. Leebo's Corner. For road racing and autocrossing, the ideal left weight percentage is 50 percent. 4. important for oval racers, especially on dirt ovals. Oval racers favor left turns so they typically desire more weight The tiles I your scales. One of the problems with cross-weight is that it will change the handling balance from a left to a right turn.