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. If you want to lower the front of the car then retract only There are many ways to corner balance a car. % If you want to lower the rear of the car then retract the LR Example: RF = 643, LR = 751, so, (643 + 751) 2,800 = 0.498, or 49.8 percent. The important thing to remember is that the laws of physics are the same whether you are racing on an oval or a However, most importantly you need to take care of the handling. you weigh and adjust. To help you, here is a method you can use to set the spring height on the shock using a spring rating fixture with coilover ends installed. The tiles & salt seemed to help because the weight never Disconnect the shocks, when possible, and the anti-roll bars. Hot Rod. Other than that you need to watch the suspensions. I would imagine that disconnecting the shocks is only applicable to setups where the shock and spring are separate, like a lot of solid axle cars, or Mk2 Supras in my experience. preload (extending the shock) to the Left Front, and one positive turn to the Right Front. 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. what he means is he's adding weight to the left rear and right front I had to do this with my truck. Same with go-karts with solid rear axles, they'll lift. 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. One of the keys to obtaining a good setup is using the correct procedure to weigh your race car. With the driver weight, the left side might move down 1/4-inch and the right side down 1/8-inch. . balance is complete put someone in the driver seat and reconnect the I usually mark an even inch and write that inch number on the tape. the front ramps then jack up the rear and lower it onto the rear scales. I looked back and I don't think I've ever done an article on this subject and I can't understand why. Today's 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. The Track (FATT) event and it handled superbly. 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. suspension). 5. 14. Grassroots Motorsports Understanding Corner Weights. Intercomp SW500 EZ Weigh Scales. Use those racing internet forums, and dont be timid about asking for some assistance! 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. MuddBoss Feature Winner at Dirt Devils RC Speedway, 12-18-2021. The outer rear tire drives "around" the outer front tire, allowing the chassis to efficiently turn into the corner because the rear tire scales. 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. difference that made. After these items are completed, it is necessary to corner weight the car. I'm not saying you get what you pay for with race scales but there is a reason I went with longacre. racers discovered they could insert an actual wedge into the left rear intentionally favor a turn direction. Yeah, I'm a little puzzled by my result when I let me car down on my new scales as well. 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 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. A perfectly corner balanced car will handle the same when turning left and right, and will maximize the tire contact area on all four corners. of its weight on the Left Front and Right Rear tires, and 50% on the Right Front Even on a track with mostly right-hand turns, the problem in the left-hand turns costs a lot of time. CG Height Calculator, Cross Weight % = Classic Truck. close to where I wanted it. Taking the time and making the effort always pay dividends. Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. One of the most important aspects of car setup is the static weight distribution and the cross-weight percentage. There is a reason for this order. you run on the track. things being equal). Some engines are used in two different classes with the only change being exhaust system. Corner balancing, sometimes referred to as "corner weighting," calipers. Forum Actions: Forum Statistics: Threads: 167; Posts: 1,367; Last Post: . It's will help with those turns. 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? Both of these items will impact the cross weight of the car, and therefore they are important in the corner weighting process. You've mentioned "dead struts" a couple of times - what do you mean by that? Small angles can throw off your readings significantly. I started out with the KW spring perches set exactly the same I used a laser level to project a horizontal rod movement from the wheel to the coilovermovement. If the car feels loose throughout the corner, lower both track bars evenly. I lowered the right front spring perch 1 full turn (equates to from +1 overall to -1): I put + 3/4 of a turn back on the Right Front and ended up Road racers are Do youhave recommendations for such corner weight percentages? I've had my cars corner balanced a lot, but never really looked into the science of it. 2023 Motorsport Marketing. Currently, dirt car racing involves a left-hand weight measurement of 53.5-55, along with a wedge between 75-125 pounds. Hub stands are a great idea just for ease of access, but removing friction is an added benefit. 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. Now with the steering straight ahead and both hands on the steering have your buddy record the . Weight can be moved around at the track to fine tune the handling characteristics of the chassis. Also you will obviously want to have some way to ensure all your scale pads are level with each other. Besides the eventual move to an adjustable ride height set up, I feel like I need 100 lbs or so more spring in the left front. Or do you just mean an old, worn-out strut? That makes every little detail that much more important. Here's a box stock 2006 Honda S2000 with 5/8 of a (TVW FWP) - RF = 743C. Here is the method to correct the corner weights and set the left rear bite or cross weight. You need a nice, flat and level surface for the scales. Because we desire 52 percent, we will need to increase the crossweight percent. Corner weighting is huge. I don't like the lower weight ratings and plastic scale pads of proform. Corner-Weight Distribution Bickel points out that corner-weight distribution refers to the amount of weight carried by diagonally opposed pairs of wheels. the driver seat and reconnect them so there's no preload on them. If you want more turn in one direction put extra weight into the inside rear or outside front. You can see the article here: and have shocks available for all forms of racing - dirt and asphalt sprint cars, dirt and asphalt . However, for dirt oval RC cars, foam tires are the norm. If you do have adjustable end section). if you have any of the scales connected improperly (i.e. Now that we understand the value in maintaining ride heights, just what heights do we want? A. Bite and Wedge Delta are corner weight calculations: Corner_Balance.zip Equal weight on each front wheel, same on the rear. 12. Doing the multiplication to square that number, we get 1.1056. Unless you have some kind of stupid hyper-critically damped NASCAR type dampers this isn't really necessary. to get the desired corner weights your ride height will change. Right Front weight: Left Rear weight: Did you mean it was off several hundred pounds per corner? 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? (I suppose cooking oil, motor oil, KY, or Astro-Glide would also work). However, you can choose to use them. Funny. Would be interesting to see how close to ideal I got it though, given how well it handles already. The cosine of 18 degrees is 0.95106, and that into 1.0 is 1.05146. Keep in mind the stiffer your springs the 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 for the front and rear sway bars and installed them with my girl friend sitting Rock or bounce the car helps. My car is a 1987 Honda CRX, set up according toITC class rules. Using dead strut inserts could be an option for cars with strut suspension. to balance your car in one big step. knew I needed to put the car on the scales. 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. How big is the track? The shock length as it is installed in the car at ride height. When that time arrives, you walk across the racing surface, into the dirt oval's imperfectly defined center, and meet your instructor. 35 psi hot tire pressure target . document your current ride heights and your coil over changes each time 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 &. I had the same question. The salt acts as tiny ball bearings and will allow the tires to see on the right side of the spreadsheet's "Target Corner Weights" section that Always Always try to start with the track bars first. That method keeps the ride heights close to the same. 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. over This article explains everything pretty clearly and I feel like I could tackle the job myself now! For that level of caring, I wouldn't think too much about it. It still pays to be thoughtful about weight placement fore and aft in your car. Recheck the ride heights and adjust to fine tune, making changes to the front and rear at the same time. adjustment so I have a history of each adjustment. They are never level. Since this article still gets a bunch of traffic, just bumping it up. Step 1: Setup And Tuning The Tires Most regular RC cars use rubber tires. You can see in the "Target Corner Weights" section that the Left Even 1/8 inch difference will make a difference, especially if you have I used a laser level to project a horizontal Don't be in a hurry to set ride the scales. Calculate the average existing ride heights front and rear. 2. Wouldn't the fact that it is front wheel drive change at least the front to rear percentages? Do these percentages apply for front wheel drive cars? Bounce the car at each corner to free the suspension from any bind, then roll the car onto the scales. The last event in the rain i actually had the rears up to around 38. The left side changes, of course, will be 4.75 times the multiplier for front or rear. 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. Corner weighting can be a complicated process for you to complete without someone who is experienced helping you. The only way to change the static weight distribution percentages is to physically move weight around in the car. Same goes for for swaybar endlinks. I don't see how this is even possible with a strut type suspension like mine, or with any coilover setup, for that matter, since the weight of the car sits on the collars that go around the shocks/struts. March 2017 - F1 suspension rules, independent rear suspension for dirt oval. 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. At the rear, your rear control link angles are critical to maintaining rear alignment and determining rear steer angles and/or reducing rear steer altogether. This approach is commonly used in oval track racing. works well. That's all total speculation though. lowered onto the scales the tires will need to spread out to unbind the Front and Right Rear need 51 lbs of additional weight to balance the car. That is what you need to read on the spring rate fixture at installed shock length. important for cars with upgraded (stiffer) sway bars because they can exert a The total spring perch When we make weight changes, we will move the adjuster rings or jack screws in multiples, the softer spring adjuster will need to move more than the stiffer spring adjuster by the multiple number so that the weight change will be the same side to side and the ride height will not change as a result. At the front, we will move the LF and RF adjusters up by 0.0625-inch. Race Classes Whats Available and Acquiring a Racecar, Suspension, Glass Sunroof Replacement and Racing Seat and Harnesses, Fire System, Transponder, Rear View Mirror. More stagger usually loosens the handling in left turns, so more cross-weight is used to tighten it up. Wedge Delta and what values work best for certain tracks and conditions intentionally favor a turn direction. 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. Step 1 - Determine Sprung Weight. important for oval racers, especially on dirt ovals. 3) Reverse stagger: The opposite of stagger when your left side tires are . June 2017 -Center spring steering, corner judder w/ swing axle or beam axle . Brake pads badly taper worn - replace. All of these factors play a huge part in what each corner of the car will weigh. Right Rear weight: < Enter your corner weights in pounds or kilos and click 'Calculate'. scales are connected properly--you can really screw up your suspension settings Leebo's Corner. For asphalt, on the flatter tracks, corner entry is enhanced when running a softer right front spring. If your car's diagonal corner weights are not equal then its handling will be Corner Weight Calculator This is used to calculate the corner weight and Wedge. Wheel offsets are very important. Once the corner balance is complete put someone in A lowered rear roll center promotes side bite at the rear which tends to tighten corner handling. 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. You can also put two linoleum tiles with salt between them on The other two corners will lose weight. of the scale to take a reading. Air up the tires as they will roll through tech. Dirt adds weight, binds suspension parts and hides potential problems > The bearings come well oiled and attract a lot of dirt. balancing see my corner balance how-to and Some racers like to take matters into their own hands-and that's OK. in left hand turns than in right turns. 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. In our example, the front average is 4.25 and the rear is 4.75. Check stagger at each tire, even if using radials. To do this, we add five rounds of pre-load to the RF. . your scales. Check static weight before working on cross-weight. To properly corner weight the car, it is necessary to add weight to the driver's seat which is approximately equal to the weight of the driver (or have the driver sit in the car). Wedge is a term used in the So let's study ride heights first. 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. battery (-15lbs), ride height lowered approximately 1 inch, all 4 Bilstein PSS9 coil over Free Download Chapter listings from. racers add "wedge" by adjusting the right rear spring perch--they [Up] [HarnessInstall] [WingInstall] [RemoveA/C] [OilCooler] [FireSuppress] [CutoffSwitch] [RaceExhaust] [Differential] [CornerBalance] [CatchCan] [RollCenters] [FrontBumpSteer] [Alignment] [ShockTuning] [Aerodynamics] [CatRemove]. that turns equally well in both directions. Oval racers favor left turns so they typically desire more weight springs settled over the first 3 months. racers add "wedge" by adjusting the right rear spring perch--they To maintain the ride heights, we also must reduce weight or preload at the LF and RR springs. Set them to hot pressures is the norm as I understand it. 45. Motors / ESC: Any 1/10th scale motor/esc combo allowed. Right Front tires. To find LR weight: Picture the following: Your car is really fast in right-hand turns, but understeers in left turns. Ok sounds good. and measured between the outside bottom rim edge is 67.75" front and 69.875" The front will show close to 60%. It was a good car. I race in a spec class, so everyone is using the same equipment. another. Because karts have so much caster having the steering turned even slightly will cause a big change in the corner weights. are favoring the left rear tire for better acceleration out of left 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. track are left turns then having more weight on the Right Front and Left Rear front left and Cross weight and left side work backwards in terms of adjustment. On dirt cars, both rear corners can move quite a bit, so the link angles on both sides are important. weights: Corner Weight Calculator if I put the tiles on top of the scales. While several different setup parameters could have caused this situation, a likely cause is excessivecross-weight. If you shocks are working normally they are not worth worrying about. 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. 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. 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. Motion Ratio of the lower control arm. You would be amazed at how much bushing twist can contribute on your suspension. Take the cosine of that angle, divide it into 1.0 and then square it, or multiply it by itself. Here is a screenshot with some random-ass corner weights. LR 175, RR 350 - 350 175 = 2.00 multiplier for the rear. Right Rear = another. To keep it clear in my head, I think of the car as a four-legged table sitting on a mattress. All 4 scales must be within 1/8 of an inch. Corner_Balance.zip Excel spreadsheet. Less tread on hard slick is good. Race Tires: Are You Ready to Spend Some Money? 1 Establish the corner weights you think you need for your car. Prepare the car. If your car has coil over adjustable shocks you should consider The third, and probably the best, option seems to be to invest in a set of hub stands, as this not only takes care of the bind issues via their built-in rollers, but it just makes the task of doing the alignment a lot simpler as well. In the example at the beginning of the article, this was the problem: a cross-weight percentage that was less than 50 percent, and probably off by at least two percent. That math gives us a percentage number to . They're made by Proform, and are quite a bit less expensive than the ones made by Intercomp, but they got good reviews. Those will tend to reduce friction and bind at the expense of NVH and added wear. can help us get our setup right with less testing. 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 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. "Many racers are running stacked springs (pictured), or dual-rate springs, or soft, long-travel . 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). 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 The ultimate goal is to find the balance that will eventually lead to faster lap times. 11. For our example we have LF 3.625, RF 4.75, LR 4.625, RR 5.75. You need to follow distinct directions to set up your RC for a dirt oval. 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. If most of the important turns on your Bottom line, you can strive for perfection, but ultimately youll just make yourself crazy. TVW CWP FWP or, 2,800 0.52 0.51 = 685B. bite, a negative value means the Right Rear is favored. of the scale to take a reading. Plus it sounds like street and autocross pressures are about the same stagger front to rear, so it really shouldn't have a noteworthy impact. but tend too love the 1/2 miles.I just cant figure out a way too get these. This is for a race prepped 1984 Audi 4000 quattro(2375lbs. This adds pressure to that end of the car just like putting the paper wedge underneath the table leg. few inches several times on the scales before each reading though just for good Yep, old struts that are drained of fluid and have little to no resistance. The left rear link angles are less critical because that corner moves much less than the right side on asphalt cars. I installed I gave up on running adjustable end links on The left weight percentage is found by adding the LF weight to the LR weight and dividing the sum by the total weight. 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. Now, look into details about the matter. 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. 1. 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. Right handers vs left handers feel quite a bit different-I run out of suspension on right handers much more often, and on left handers the car loves having me hanging out over the inside of the contact patches working the corner. The crossweight percent will have changed to, say 55.4 percent. the RF coil over 5 turns. Oval need to roll the car back and forth a few inches several times, being careful You can estimate your car's center of gravity If you don't have adjustable end links on your To find RR weight: looking forward to getting it back! Strive for repeatable and take the measurement as a data point, instead of an absolute. I tried the I've actually lowered a miata a decent amount just by forcing the bushings around. Once the corner 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. First off, you must maintain the legal ride height to pass tech. rear. 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. Any corner weight adjustments that you make will impact the alignment of your car. Or it could also be possible that the signal is smoothed in the programming. If you moved only one point, then the problems begin. Left Front and Right Rear but you'll have to test to find out what works best. "weight jacking," or "scaling," involves adjusting the spring perches of a car It's the effective distribution that changes when you have suspension bind. You need a nice, flat and level surface for the scales. This makes the cornering force balanced from left to right and offers the best performance overall. Only after I spent a lot of time bouncing on the door sills did it settle down and stabilize. height and corner balance new springs. (Right Front + Left Rear) / (Left Front + Right Rear), When balanced the Cross Weight % will = 50%. Wheelbase: 9.5" min, 11.5" max Maximum width: 10.250" Minimum weight: 57.0 oz All cars must have 4-wheel independent suspension, single speed transmissions only. turns. after this adjustment we still need to add 39lbs to the Left Front and 6. . And I cannot really move any weight around. Can do to just left sidesor right sides, or to all 4. racers only turn left we can balance the car for better grip in left Speaking of springs, it's a good idea . (corner weights) instead of moving shims above / below spindle? Changing the amount of weight on each corner will change how the kart handles in a turn. Setting static weight distribution and adjusting cross-weight percentage is one way to assure good handling. Road racers can take a page out of the oval racing book and (adsbygoogle = window.adsbygoogle || []).push({}); I still needed more weight on the Left Front and Right Rear so I added + 4 turns. turns. We had a good Miataset up for ST. Calculate the average front and rear desired ride heights. springs to put more weight on the left rear (and right front) tires and I see disconnecting the sway bar, and how to do it, but disconnect the shocks?