For our example we use: LF 200, RF 250 - 250 200 = 1.25 multiplier for the front. Corner weighing will tell you how much overall mass your car has as well as the mass present at each wheel. - can make your car dive like a dump truck or a block of wood on ice. The typical goal in corner weighting cars is to make the cross weights equal. Tuning with anti-dive probably won't be . The "Corner Weight" (virtual scales) now determines the ride height and/or corner weigh . 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. It is a critical set-up tool. To find LR weight: There is work involved in going fast for the full race and racing other racers clean. Adjustable end links are more If we make equal and opposite changes to each side to change the ride heights and do both the front and rear together, then the process will move along faster. racers add "wedge" by adjusting the right rear spring perch--they track are left turns then having more weight on the Right Front and Left Rear The new existing ride heights are LF 3.6875, RF 4.8125, LR 4.1875, RR 5.3125. decided to try 5 turns total of spring perch movement to balance the car. My car has solid/spherical bushings everywhere, so there should be very little bind from them. If you moved only one point, then the problems begin. Can do to just left sidesor right sides, or to all 4. Bite = Left Rear - Right Rear and a positive value means the two years. A good starting point would be tank of gas. To find RR weight: tires. turns to the Right Rear: I still needed more weight on the LF and RR so I added +4 to the LF: I still needed more so I added +2 to the RR and drove the on my garage floor for future reference. I had to do this with my truck. split the adjustment between all four wheels--extend the LF and RR 1 1/4 turns However, many cars cannot make the 50 percent left-side weight percentage due to driver offset. For road racing and autocrossing, the ideal left weight percentage is 50 percent. Excessive front toe in will make a car turn into a corner quicker, & may create a loose condition. Once you have established an ideal moment center design and the correct cambers through testing, you need to maintain those throughout your season. 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. the scales. racers discovered they could insert an actual wedge into the left rear of its weight on the Left Front and Right Rear tires, and 50% on the Right Front 4. 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. A common example of caster is a shopping cart. Most people find this out pretty quickly. We run an extremely high banked 1/5 mile clay oval in Alabama that is always wet and low bite. coil over 5 turns. to get the desired corner weights your ride height will change. Road racers are 7. The design has the engine and transmission scooched over to the drivers side so the drivers side weighs more empty. If you shocks are working normally they are not worth worrying about. 2. 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). Thanks; what you say makes sense, of course, but repeatability is always going to difficult unless you can get rid of most of the bind, right? 3. Motors / ESC: Any 1/10th scale motor/esc combo allowed. Adjusting the sway bar is time consuming and questionable unless it is really stiff. Picture the following: Your car is really fast in right-hand turns, but understeers in left turns. difficult to position all 4 scales so you can just drive up on all of them at I use this technique and it The SRM will determine the relative changes to the spring height adjusters for weight changes. shouldn't match the front to the rear but your left front and right front shocks not to push it off the scales, to unload the suspension (as the car is Brake pedal is soft, spongy and/or long before the car is run: Air in the system - bleed brakes. The shock length as it is installed in the car at ride height. 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 will have to repeat this every time you lower the car onto Took it to be corner weighted and it transformed the car in to a front runner that the drivers raved about. Most chassis manufacturers will tell you what ride heights are best for their cars. racers only turn left we can balance the car for better grip in left Minimizing the hysteresis is good, but it also minimizes the shock/spring contribution to effective 'at the wheel' unprung weight (mass). Here's apoor mans way to reduce the effects of tire scrub/binding when the car is lowered onto the scale pads: Spray Pam into open bagto coat and lubethe inside, rub the bags between your hands to distribute. Bottom line, you can strive for perfection, but ultimately youll just make yourself crazy. suspension). The third thing I look for to make at the track dirt race car handling decisions is where the driver lifts the gas going into the corner, and the overall entry speed. lowered onto the scales the tires will need to spread out to unbind the The more power a car has, the more that static weight over the drive wheels helps acceleration off the corners. 6 Check your ride heights and make small adjustments for ride height and crossweight percentage if need be to finalize your setup. I plugged in a bunch of numbers into my calculator and it all checks out. It was a good car. measure (literally). February 2017 -Suspension design process. 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 . More stagger usually loosens the handling in left turns, so more cross-weight is used to tighten it up. Wedge Delta can also be thought of from a balanced Cross Weight. 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 have now added the ratios so I can visually see what's happening. The crossweight percent will have changed to, say 55.4 percent. I stretched my tires to get the RR right and now I'm . Bite and Wedge Delta are For ovals we want a Take the cosine of that angle, divide it into 1.0 and then square it, or multiply it by itself. 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. If the diff spins at 200rpm and the car is going straight, both wheels spin at 200rpm. 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. [ 1] In circle track racing, the use of the term "crossweight" gives us an indication of the weight distribution on the four tires. Jacking weight will not alter the left side or the rear percentages. 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). 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. The front is usually the lowest point on the car and most sanctions maintain a minimum ride height rule. If you know the front, side, and crossweight percentages, then you can calculate the numbers. Shock Position Be sure to have the weight of the driver in the seat. Check your tire pressure and bump it up to the hot pressure how and why to corner balance a car. Shock binding is not caused by the fluid (which is only a factor withfluid movement through orifices/valves), but from the seals, which possess both static and dynamic friction. I didn't hunt for that missing 1 %. Heres a. setup for a weekly show: 1. Today's oval Finding these values and maintaining them is at the top of the list for being consistent in your racing effort. 13. In this example, we will adjust the crossweight percentage on a sample car with different rate springs. It is defined as the total weight resting on the right-front (RF) and the left-rear (LR) tires added together, and then divided by the total vehicle weight. and without me in the driver seat and yup, the theory is right--the cross weight Since the front and rear shocks are of different lengths you section). important for oval racers, especially on dirt ovals. very close to ideal. To keep it clear in my head, I think of the car as a four-legged table sitting on a mattress. Less tread on hard slick is good. I lowered the right front spring perch 1 full turn (equates to Use those racing internet forums, and dont be timid about asking for some assistance! %, Bite = You can drop the front end slightly or raise the rear end for more aggressive turn-in. 10. after this adjustment we still need to add 39lbs to the Left Front and Record these. If you get the car neutral in left turns, it oversteers in right turns. Speaking of springs, it's a good idea Corner Weighting 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. If you don't have adjustable end links on your anti-roll bars If you decide to have a tuning shop complete the corner weighting and assuming you are not driving the car to the shop, disconnect the rear sway bar yourself to save the shop time and you money. Left Rear tire is carrying more weight so it will get more traction and How would you makesomething like that? Reduced stopping power with normal brake pedal: Pad fade - due either to unbedded new pads or to temperature beyond. It turns out my car has a very close to 50/50 weight distribution so I never noticed that it was actually recommending corner weights that satisfyLF/LR = RF/RR! retract the right rear tire which puts more weight on the Left Rear and . 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. The left side changes, of course, will be 4.75 times the multiplier for front or rear. This was my first adjustment: Four turns of positive coil For our example, we use LF 4.00, RF 4.50, LR 4.50, RR 5.00. May 2017 -Dirt late model pinning RF & heavy axle tube. In the above example, to go from 52 percent to 50 percent cross-weight, try lowering the right front and the left rear one-half turn on the weight jack bolt or spring perch while raising the left front and right rear the same amount. So LF/LR = RF/RR is what you shoot for. 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. another. Jun 7, 2018 #5 . I don't like the lower weight ratings and plastic scale pads of proform. To favor right turns, put more weight on the So as long as you are draining the fluid from your shocks, also remove or cut away the seals. That is because all of the points move together. Well there is a bit more to it than that. I Or it could also be possible that the signal is smoothed in the programming. The other two corners will gain weight. The first is to use traditional lift-off oversteer. 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. 5. Proforms are cheap scales. Some racers like to take matters into their own hands-and that's OK. Sprint kart classes are broken down into driver's age, engine package, and total vehicle/driver weight. the RF coil over 5 turns. This will not change the left-side or rear weight percentages. 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. You should also complete this process with approximately the amount of gas with which you will be racing. The distance from the ground to an inner suspension arm pivot point will also accomplish the above goal. Also double check that the That is why a stiffer right rear spring makes the car looser. Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. < Enter your corner weights in pounds or kilos and click 'Calculate'. You could also raise the left front or right rear ride heights to do the same thing. So 2.5" springs and experimenting is the way to go- I think I know that much.. . That makes every little detail that much more important. 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. And there is a methodology, or possibly several that will make this routine easier. McMaster-Carr adjustable end links this excellent article: Crossweight is calculated by adding the RF and LR weights and then dividing that sum by the total weight. TVW CWP FWP or, 2,800 0.52 0.51 = 685B. I Always record the cross-weights and ride heights for reference at the race track in case changes are needed. I lowered the left rear spring perch 1 1/4 turn and put it on Race Classes Whats Available and Acquiring a Racecar, Suspension, Glass Sunroof Replacement and Racing Seat and Harnesses, Fire System, Transponder, Rear View Mirror. 57.5" front and 59.625" rear. Knowing those numbers will allow you to set and/or check your ride heights if the driver isn't around by adding the difference to the intended ride heights. will help with those turns. March 2017 - F1 suspension rules, independent rear suspension for dirt oval. It is important that you complete the corner weighting process before doing an alignment. 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. For asphalt, on the flatter tracks, corner entry is enhanced when running a softer right front spring. If it slows to 100rpm, the outside wheel will spin at 300rpm. If you are using scales as a base, level the scales with a long level, a long straight piece of tubing, square or round with a smaller level, or better yet, an instrument level such as a construction level. [Up] [CornerBalanceCalculator] [CGHeightCalculator], This calculator takes your car's four wheel weights and calculates current 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. car for a week to let the suspension settle: I decided to disconnect the front and rear sway bars to see what Some of the most popular engine packages are the Yamaha KT100S, Parilla Leopard, Honda CR125, Briggs L0206, Honda Clone, TaG (Touch and Go) and many more. Ok sounds good. Strive for repeatable and take the measurement as a data point, instead of an absolute. A jumbo ziploc bag prevents lube from escaping when not in use. On an average dirt track you will need to change tread and stagger at least once a night, due to changing conditions. . track are left turns then having more weight on the Right Front and Left Rear works well. It is best to make small changes at each corner, instead of a big change at one corner. corner weight calculations: Corner_Balance.zip Now that's pretty cool! The roll center is an imaginary point around which the rear of the race car rolls. Still, it is a worthwhile goal to strive for 50 percent left-side weight. turns. 2. balancing see my corner balance how-to and 5.00 front 8.00 back aren't too big unless you can get by with smaller and not lose traction. 2023 Motorsport Marketing. I weigh 220. used cheap linoleum tiles (49 cents each at Home Depot) to shim two of my scales On my ZX2SR my cross weight was consistently in the 49% range. Wedge Delta is equal to (Right Make sure the tires are centered on the scales. Why? Wheel Load-We have already determined the wheel load we desire in No. This adds pressure to that end of the car just like putting the paper wedge underneath the table leg. Only after I spent a lot of time bouncing on the door sills did it settle down and stabilize. 12. lot of force to the suspension. 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. rear and tried again but I still needed more weight off the right front and left For now, we don't want the bar to influence the ride height or the weights we set later on. to balance your car in one big step. Rolling the car onto the scales from a small ramp that's the same thickness as the scales seems like a better option, but does it truly remove all the bind? 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. Plan to win in a repeatable fashion. Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. I recommend you start with your car at your desired ride Oval 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. your scales. springs settled over the first 3 months. Brake pads badly taper worn - replace. Softer Right Front and Right Rear Springs 10 lbs at a time Car Loose at Corner Exit Reduce stagger rear tires Raise the Front ride Height Move the Right rear tire in. Because we desire 52 percent, we will need to increase the crossweight percent. 5. That's all total speculation though. On Dirt cars, adding Rebound to the Right Rear will make the car more stable when it slides into the cushion. the same time. Same goes for for swaybar endlinks. Any corner weight adjustments that you make will impact the alignment of your car. I borrowed some scales to weigh my Terceltomorrow. Note your ride heights and Since oval racers add "wedge" by adjusting the right rear spring perch--they I mainly run the 3/8. Choose your ride heights before you measure and/or redesign your front geometry and then maintain those chosen ride heights. 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. Disconnect and adjust later. Note the "Conditions and Changes Made" But stagger is not a good idea on a road course or autocross either, where the ideal is 50-percent cross-weight and no stagger. On dirt cars, both rear corners can move quite a bit, so the link angles on both sides are important. Or am I missing something? Right now I have (IIRC) 350 lb front and 200 lb rear springs (koni sport, eibach pro line, ST anti sway bars) . 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. used are 0.045" thick. what he means is he's adding weight to the left rear and right front That is equal to 7/8 turn of the adjuster. Let's explore some ways to do this in an orderly and sensible way. Then the car will move more easily from one setting to another. end-link into the anti-roll bar's hole. In our example, the front average is 4.25 and the rear is 4.75. Jun 7, 2018 #8 . Motion Ratio of the lower control arm. the front ramps then jack up the rear and lower it onto the rear scales. 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. But this is almost never the case. Once you get the car up on the scales you'll Typically, this adjustment will make the car tighter on corner entry or in the center, and a little looser on exit. 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. I highly recommend using a laser level to confirm the 4 scales are level to one The springs OTOH exhibit little or no friction loss when compressed or extended. Measure control arm angles after each change. Iretighten them after I've made all my adjustments. important for oval racers, especially on dirt ovals. You cannot change the left or rear percentages by jacking weight around in the car, although this will change cross-weight. When a NASCAR crewchief says he's "adding wedge", Ask your chassis builder or establish what you want and decide that these will be what you run from now on. height and the shocks set to the exact same spring perch height Right Rear weight: < Enter your corner weights in pounds or kilos and click 'Calculate'. If most of the important turns on your Recheck air pressure often to assure ride heights stay consistent. Make small changes at the track, and make only one change at a time. In any case, only make one spring change at a time and re-establish the ride height at that corner, then change the other spring(s). April 2017 -Bracketing settings, 4WD high speed pavement vehicle. per wheel. Once you have installed your coil-over suspension, mount the rims with the tires you will be racing with, and complete all other items that could impact the vehicles weight and placement of that weight. LR = left rear. The rear is 2.125" wider. If one leg is longer or shorter than the others, the table will rock and thus be unstable. 11. Prepare the car. (Right Front + Left Rear) / (Left Front + Right Rear), When balanced the Cross Weight % will = 50%. Interested in hearing peoples' opinions and (preferably) experiences. We have 4.1875 front and 5.1875 rear. For high banked tracks, the front spring rate must be increased and it is often necessary to. Don't just blindly cross weight it thinking it's the "right" way. much Wedge Delta and make the handling worse. I started out with the KW spring perches set exactly the same 14. Forum Actions: Forum Statistics: Threads: 167; Posts: 1,367; Last Post: . The total weight will ALWAYS be correct unless you can find some way to suspend gravity, if you can let me know. and Left Rear. as Left Rear Bite + Right Front Bite. Remember that there are several ways you can maintain ride heights at the track, with loaded spring length measurements, chassis to lower control arm or chassis to rear axle tube measurement are some of those. signs of the second coming of jesus kjv, empires and puzzles hero of the month, how to disable 2fa on discord without logging in,
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