it would help the car turn left and accelerate better. split the adjustment between all four wheels--extend the LF and RR 1 1/4 turns Disconnect the shocks, when possible, and the anti-roll bars. Proforms are cheap scales. That method keeps the ride heights close to the same. I use 2x6 wood planks as ramps to drive the car onto 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. 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. However, most importantly you need to take care of the handling. 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. line above each scale and placed a ruler on the top Most chassis manufacturers will tell you what ride heights are best for their cars. There are many ways to corner balance a 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. Calculate the average existing ride heights front and rear. I guess I should work on losing weight personally (i am 220~). 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. Andy Hollis does this. Only after I spent a lot of time bouncing on the door sills did it settle down and stabilize. shocks set to same length left to right (front to rear will be different). 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. each and retract the RF (Right Front) and LR 1 1/4 turns each. (I suppose cooking oil, motor oil, KY, or Astro-Glide would also work). of the scale to take a reading. 1 Establish the corner weights you think you need for your car. Moving or removing weight is one Replacing a heavy battery with a light weight one allowed me to get close . 11. I 3 To make changes to establish the crossweight percent, we scale the car and record the crossweight percent. 5.00 front 8.00 back aren't too big unless you can get by with smaller and not lose traction. 4 Things You Should Never Do In A Front-Wheel Drive Car things being equal). Now that we understand why we need to maintain a set ride height, let's go through an example of how to set ride height. Even on a track with mostly right-hand turns, the problem in the left-hand turns costs a lot of time. 10. The Circle Track Analyzer is a computer program that simulates most any car you can design, racing on most any size oval track. This obviously means that decreasing cross weight or left side weight much Wedge Delta and make the handling worse. 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. Find the difference from the desired average ride heights. If it slows to 100rpm, the outside wheel will spin at 300rpm. Less tread on hard slick is good. LR coil overs 2 1/2 turns. CG Height Calculator, Cross Weight % = it would help the car turn left and accelerate better. It's just turning left 2 times per lap. will help with those turns. First some baselines. Make sure all of the weights are in the car including fuel, oil, battery, cooling water, hood, and so on, or weights that will simulate those. If you want to lower the front of the car then retract only Once you have returned the wheel corresponding to the spring change back to its measurement, the other wheel measurements will be OK. 3. When working with static weight distribution, we use two percentages to analyze the car's corner weights: Left weight percentage and rear weight percentage. Afterward you need to adjust the settings to the correct maneuvers. turns. Corner Weight: (1/2 the front or rear weight) Use an accurate racecar scale that will weigh each corner of your car. Rear weight percentage for road racing and autocrossing is less definite. to get them exactly level. This makes the cornering force balanced from left to right and offers the best performance overall. Astrut with its innards removed? Corner Balance Calculator - Rob Robinette You can see the article here: This article explains everything pretty clearly and I feel like I could tackle the job myself now! Many successful race teams use corner weighting to achieve the same F/R % on both sides equal, not cross weight. 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 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. Even if you pay someone a small amount of money for their help, it will be far better than buying the scales yourself. There is work involved in going fast for the full race and racing other racers clean. springs to put more weight on the left rear (and right front) tires and Search for: You can also put two linoleum tiles with salt between them on Ok sounds good. Then if it's for a particular road course, you will find several seconds optimizing for select turns and throwing any of the above methods out the window A friend's Chump Car found 2 sec at VIR making it turn right better than left. Then just leave them attached. That is why it gets tighter. "two linoleum tiles & salt" technique to allow the tires to slide on the scales turns. Corner-Weight Distribution Bickel points out that corner-weight distribution refers to the amount of weight carried by diagonally opposed pairs of wheels. The only way to change static weight is to physically move weight or ballast in the car. . Check your tire pressure and bump it up to the hot pressure left to right (measured with a digital caliper) and my ride height was pretty 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 and without me in the driver seat and yup, the theory is right--the cross weight For street cars it certainly can be. The nose weight is simple to remember the tricky ones are - cross and left side adjustments. The design has the engine and transmission scooched over to the drivers side so the drivers side weighs more empty. 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. If the driver lifts early but still has a fairly good amount of roll speed into the corner, there probably isn't much brake being used. To increase rear weight, move weight as far back as possible. Bounce the car at each corner to free the suspension from any bind, then roll the car onto the scales. The other two corners will gain weight. 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. Road racers are turning the front wheels to measure caster. the sway bars because they fail so often and the bars only added a couple of No, not as in the law, but in being legal in tech. Caster creates stability as the geometry . I recommend adding an eighth or slightly more to the lowest corner just to make sure you pass tech. Corner weights-cross weights - TenTenths Motorsport Forum Mudboss Setup #3 - Traxxas Slash transmission setup and diff - YouTube A good starting point would be tank of gas. To favor right turns, put more weight on the over Now that the car has the correct ride heights and weight distribution for your setup, you need to make sure those don't change at the track. but tend too love the 1/2 miles.I just cant figure out a way too get these. On my ZX2SR my cross weight was consistently in the 49% range. One of the problems with cross-weight is that it will change the handling balance from a left to a right turn. of the scale to take a reading. That seem like a lot. The spreadsheet's second page has a good article that goes into more detail of Thinking about this a little, the weight measured by the scales is the sum of the force of gravity acting on the car's mass, and the force of the springs pressing downward. In circle track racing, we often, and almost always, have different rate springs on each corner of the car. You've tried springs, shocks, different bars, neutralizing the anti-roll bar, and nothing seems to work. left to right. 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. Suggested Adjustment Procedure for Oval Track - KONI NA the same time. Cross weight and left side work backwards in terms of adjustment. Guess I have to try it. Do these percentages apply for front wheel drive cars? Understanding How Weight Distribution Affects Your Race Car The advantage to wedge is that the left rear tire carries more load, so the car drives off the turns better. 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. If you moved only one point, then the problems begin. For information on corner Are they adjustable? 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. springs settled over the first 3 months. Here's the car with the same settings but empty: I took the newly corner balanced S2000 to a Summit Point Raceway Friday at All rights reserved. My track width with CE28 17" x 9" wheels Let's explore some ways to do this in an orderly and sensible way. the front ramps then jack up the rear and lower it onto the rear scales. 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. The distance from the ground to an inner suspension arm pivot point will also accomplish the above goal. If most of the important turns on your Your ride heights determine your arm angles up front, as well as the cambers, and, to a lesser degree-excuse the pun-the caster angles. On an average dirt track you will need to change tread and stagger at least once a night, due to changing conditions. (CG) height by using this online calculator: CG Height Then move components like the battery or fuel cell. Timely refresher that leaves me with a question Ive had for the last couple years that I have not found an answer to in hours of searching. Recheck the ride heights and adjust to fine tune, making changes to the front and rear at the same time. The following weights are with the front Comptech adjustable For our example we have LF 3.625, RF 4.75, LR 4.625, RR 5.75. I've had my cars corner balanced a lot, but never really looked into the science of it. Always try to start with the track bars first. (Right Front + Left Rear) / (Left Front + Right Rear), When balanced the Cross Weight % will be 50%. First off, you must maintain the legal ride height to pass tech. 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. rear. the scales. The driver is optional based on No. Lay the bag flat onto the scale pad, partially open to vent, lower the car into the bag. 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. suspension). % Would be interesting to see how close to ideal I got it though, given how well it handles already. I primarily just making sure it meets class mininum weight, but I may mess with the balance if its off by much, but I dont think it is. of its weight on the Left Front and Right Rear tires, and 50% on the Right Front For example, if you are racing the Briggs Light class at 305 pounds, your corner weights should be: LF = 68 pounds RF = 68 pounds Left Rear tire is carrying more weight so it will get more traction and It seems to me that if there's bind in the suspension that's preventing all the force of the springs to come into play, the weight read by the scales will be less than the correct value. The ultimate goal is to find the balance that will eventually lead to faster lap times. When I drive down a strait road the I can clearly feel that the drivers side is heavier over bumps expansion joints and dips and the like. 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. car for a week to let the suspension settle: I decided to disconnect the front and rear sway bars to see what 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. Use those racing internet forums, and dont be timid about asking for some assistance! 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. Delta which is simply the difference between the two diagonal tire weights. Now that we have established the ride heights, our weights could be anywhere. Note your ride heights and Corner Weight Calculator | GTSparkplugs lowered onto the scales the tires will need to spread out to unbind the the scales. 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. Why? A trucking company scale meant to weigh 80,000lbs may not be accurate enough for a 3000lb car. Once you have established an ideal moment center design and the correct cambers through testing, you need to maintain those throughout your season. 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. Corner weighting can be a complicated process for you to complete without someone who is experienced helping you. Avoids a mess on scale pads and tires,prevents dirt fromcontaminating lube. Road racers are The rear is 2.125" wider. Bite and Wedge Delta are Do youhave recommendations for such corner weight percentages? , = change needed to get to target weight, Cross Weight = you run on the track. Toe inn a 1/4 inch. difficult to position all 4 scales so you can just drive up on all of them at The only way to change the static weight distribution percentages is to physically move weight around in the car. The SRM will determine the relative changes to the spring height adjusters for weight changes. Air up the tires as they will roll through tech. Get the rear percentage as close to the manufacturer's specs as possible. The process is so basic to the setup of the car. pad capacity. But in a right turn, the opposite occurs and the handling is worse. Tuning with anti-dive probably won't be . . [Up] [CornerBalanceCalculator] [CGHeightCalculator], This calculator takes your car's four wheel weights and calculates current If you want to raise the front of the car then extend only the typically not concerned with bite and wedge delta because they usually I dropped my integra off at edge to have this done today. All of these factors play a huge part in what each corner of the car will weigh. your scales. which is simply the difference between the two diagonal tire weights. 3. as Left Rear Bite + Right Front Bite. You're better off not corner balancing the car than doing it on an unlevel How to Adjust iRacing Sprint Car Cross Weight AKA Wedge cross weight. Because karts have so much caster having the steering turned even slightly will cause a big change in the corner weights. If you want more turn in one direction put extra weight into the inside rear or outside front. not to push it off the scales, to unload the suspension (as the car is I installed Do not adjust any other wheel's spacing. Do this by making equal changes to the adjusters on each side. Forum Actions: Forum Statistics: Threads: 167; Posts: 1,367; Last Post: . Weight Training: Everything You Need to Know About Race Car Weight scales are connected properly--you can really screw up your suspension settings 2. 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. Since the front and rear shocks are of different lengths you 13. Vehicle Scales | Corner Weight Race Car Scales - Speedway Motors . With my KWV3 shocks I had to remove the wheel to adjust the 4m.net - The Most Opinionated Racing Message Board In The Universe. In the old days when we ran close to equal springs at the front and at the rear, we could just put one round in the RF and one out of the LF, one in the LR and one out of the RR to put cross into the car. The outer rear tire drives "around" the outer front tire, allowing the chassis to efficiently turn into the corner because the rear tire 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. This is for a race prepped 1984 Audi 4000 quattro(2375lbs. Today's oval And there is a methodology, or possibly several that will make this routine easier. RC Dirt Oval Car Setup & Tuning Guide [5 Key Steps] My starting cross weight was 50.6%, I was off 7lbs 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). 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. 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. In our example, move the LR and RR corners down by 0.4375-inch. The fact about this concept is when you put a softer right rear bar in, the car rolls more to the right rear but it is actually transferring less weight. I'm off by 0.1% (see numbers on left side of the spreadsheet). 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. The cosine of 18 degrees is 0.95106, and that into 1.0 is 1.05146. - Use blocks the same height as your scale pads to move the car off the scales to make adjustments. Here's the ending corner weights with no driver and 9/10 fuel: Grassroots Motorsports Understanding Corner Weights. Most people find this out pretty quickly. 57.5" front and 59.625" rear. 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. Adjusting the corner weights is how we establish the crossweight percent, or what is often referred to as the amount of bite, left rear weight, or wedge. To increase left-side weight, move weight as far to the left as possible. 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. It's stuff closer to 60/40 or 40/60 where you need to stray from crossweighting. 4 Establish the exact weight change in percent that a given spring height change will make and record that number. important for oval racers, especially on dirt ovals. I was surprised how much these high rate Corner weights and chassis balancing - R/C Tech Forums hard work but it makes all that high dollar suspension work together the way its When you lower the panhard bar the rear roll center drops. (i.e., if we move the RF adjuster two rounds, then we will move the LF adjuster 2.5 rounds.) This keeps the ride heights as close to ideal as possible. Typically, this adjustment will make the car tighter on corner entry or in the center, and a little looser on exit. balance is complete put someone in the driver seat and reconnect the How To Understand Differentials - RC Car Action You can estimate your car's center of gravity intentionally favor a turn direction. 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. Changing the ride height at any corner will change the cross-weight percentage. (TVW LSP) - LF = 769D. Wheel offsets are very important. Cross Weight Calculator | Eldridge Racing | Micro, MiniSprint Parts and . A place where you can add in your Photo Galleries. I use this technique and it Bite tells us how much we Dirt adds weight, binds suspension parts and hides potential problems > The bearings come well oiled and attract a lot of dirt. the front ramps then jack up the rear and lower it onto the rear scales. The car is built on a jig for a particular ride height layout. Circle Track Analyzer - Performance Trends Sprint kart classes are broken down into driver's age, engine package, and total vehicle/driver weight. We don't ever move weight around to get crossweight, but we do move weight to change our front-to-rear percent or the side percent of total weight. are favoring the left rear tire for better acceleration out of left Doing the multiplication to square that number, we get 1.1056. They are never level. 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. It is best to make small changes at each corner, instead of a big change at one corner. Step 1: Setup And Tuning The Tires Most regular RC cars use rubber tires. You will have to repeat this every time you lower the car onto Setting Up Your Traxxas Slash | Traxxas Now that's pretty cool! % 50% is optimal, Wedge = , Left Rear = To find LF weight: values shown below are totally fictional. We should now be at, or near, the desired crossweight percent. scales. Adding more rebound to the car will make the car more stable on rougher tracks. Moving weight to the front of the kart will provide more front-end grip. Tell the shop you will be disconnecting the rear sway bar when obtaining the estimate. racers discovered they could insert an actual wedge into the left rear This gets very tedious, given the number of iterations it typically takes to get the corner weights right. It's critical that you set ride height in the same place each and every time you do it. To add weight to a given corner, raise the ride height at that corner or lower the ride height at an adjacent corner. So LF/LR = RF/RR is what you shoot for. Make small changes at the track, and make only one change at a time. cars through the corners and thats where there eating me up. In order to perform the set up routine the car needs to be completely ready to race. Funny. I race in a spec class, so everyone is using the same equipment. If your car has coil over adjustable shocks you should consider How to Properly Use a Penske Shock Tuning Guide to Optimize Your Here are some setup tips that will help you really get the most of of your Slash: > Keep it clean. Wedge Delta should be positive for oval racing. Brake pads badly taper worn - replace. In oval racing you always run more weight on the LR. Bite tells us how much we used linoleum tiles to shim two of my scales to get them all level. Road racers can take a page out of the oval racing book and 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. If you get the car neutral in left turns, it oversteers in right turns. Any corner weight adjustments that you make will impact the alignment of your car. To keep things clear I call this added LR/RF weight Wedge Corner_Balance.zip, Excel Corner Balance Spreadsheet Screen Capture. Weight can be moved around at the track to fine tune the handling characteristics of the chassis. The vanilla neon setup would be SDK suspension (stock ACR, look at neon.org and figure out what you have) with 3.5 deg front camber, 1 to 1.5 rear, zero to 1/8" in toe front and rear. tires. knew I needed to put the car on the scales. need to roll the car back and forth a few inches several times, being careful 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). Oval Set-up Black Book | IROAR - Radio Control Racing Calculate the spring rate multiples.