Setting Ride Height & Corner Weight - Circle Track Magazine - MotorTrend does not change when a driver is added. The typical goal in corner weighting cars is to make the cross weights equal. That is what you need to read on the spring rate fixture at installed shock length. To find RF weight: what he means is he's adding weight to the left rear and right front Picture the following: Your car is really fast in right-hand turns, but understeers in left turns. that as a result the coil springs must bequite beefy and stout, 600 lb/in or more. two years. A place where you can add in your Photo Galleries. Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. suspension). So let's study ride heights first. Always positive Bite and positive Wedge Delta. 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. TVW - (RF + LF + LR) = 603. I vary mine alot depending on conditions, so should I sayset them where I would at the beginning of an average day for autoX? Bite and Wedge Delta are Always record the cross-weights and ride heights for reference at the race track in case changes are needed. Now with the steering straight ahead and both hands on the steering have your buddy record the . Be sure to have the weight of the driver in the seat. Typically, a road racing car should have 50% Caster and Caster split can be adjusted to find more speed and stability. So 2.5" springs and experimenting is the way to go- I think I know that much.. . This obviously means that decreasing cross weight or left side weight 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 dry)! "Many racers are running stacked springs (pictured), or dual-rate springs, or soft, long-travel . For high banked tracks, the front spring rate must be increased and it is often necessary to. left to right. 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. 5. used cheap linoleum tiles (49 cents each at Home Depot) to shim two of my scales I didn't hunt for that missing 1 %. balance is complete put someone in the driver seat and reconnect the 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. The "ULTIMATE" Racing Car Chassis Setup Guide and Tutorial 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. Cross Weight % = 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. need to roll the car back and forth a few inches several times, being careful If you're setting up a FWD race car, and you can see this in historical VW Golf or original Minis, they often lift and inside rear-wheel. 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. Road racers can take a page out of the oval racing book and Plan to win in a repeatable fashion. For ovals we want a to balance your car in one big step. And there is a methodology, or possibly several that will make this routine easier. adjustments were 1 turn to the right front and 3/4 turn to the left rear. RC Dirt Oval Car Setup & Tuning Guide [5 Key Steps] Similarly, dirt oval cars often represent crossweight as "bite", or weight on the left-rear tire relative to the right-rear tire. Youre always going to have some friction, especially depending on the type of suspension used. 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. A set up plan will help you to build a race winning effort. Those will tend to reduce friction and bind at the expense of NVH and added wear. 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. These tell us all we need to know about the setup relative to the weight distribution. A. end-link into the anti-roll bar's hole. 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. Basically - after you finish the set up routine, the car goes in the hauler. 50% then Wedge Delta will be 0. % Wedge Delta will be 0 at 50% Wedge. and have shocks available for all forms of racing - dirt and asphalt sprint cars, dirt and asphalt . There are legal issues too at the front. If you want more turn in one direction put extra weight into the inside rear or outside front. 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. so the suspension can settle and unbind. Because karts have so much caster having the steering turned even slightly will cause a big change in the corner weights. Remember that changes in stagger, tire pressures and springs will change the ride height and alter the cross-weight percentage. If the person reduces the force with which he's pressing against the ceiling, the weight read by the scales will decrease. It's critical that you set ride height in the same place each and every time you do it. Heres a. setup for a weekly show: 1. The overall effect is much like having no shock in the equation. 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. 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. If one leg is longer or shorter than the others, the table will rock and thus be unstable. as Left Rear Bite + Right Front Bite. Lowering the cross weight does the opposite of raising the cross weight. pad capacity. 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. Wedge Delta should be positive for oval racing. Tell the shop you will be disconnecting the rear sway bar when obtaining the estimate. 12. extra weight is on the left rear and right front tires which gives them more The total weight will ALWAYS be correct unless you can find some way to suspend gravity, if you can let me know. 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! positive Bite and positive Wedge Delta. Brake pads badly taper worn - replace. I borrowed some scales to weigh my Terceltomorrow. The situation isfrustrating. difference that made. The first spreadsheet below is what I started with. spread when the car is lowered onto the scales. What Spring Rates To Use In Your Race Car - MotorTrend 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. Maybe there's some sort of bind in the scales. 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. How big is the track? box in the "Ride Height" section of each spreadsheet. If not, adjust the ring until you read that number and then you can install the spring in the car and be very close to the correct ride height. from a balanced Cross Weight. As with the table, the corresponding diagonal corner of the vehicle gets more of the car's weight. you raise the rear of the car 10 inches or more and re-weigh it. These are your target weights which will yield a 50% Cross Weight: Left Front = You can see in the "Target Corner Weights" section that the Left Setup Tips for Asphalt Oval Racing lb driver, no passenger, spare tire removed, soft top up, Magnaflow mufflers (-20lbs), Braille oval racing world and is simply another word for Cross Weight. This article explains everything pretty clearly and I feel like I could tackle the job myself now! Beginners Guide to RC Racing Oval - TheRCProShop.com Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. Find a fairly level spot and mark on the ground with duct tape or marker where the tires sit on the ground. . turns. They are not too suitable for racing and oval dirt cars. Steve Smith Autosports - Tech Tips The less fuel in the tank the tighter the chassis will become. Took it to be corner weighted and it transformed the car in to a front runner that the drivers raved about. You can also put two linoleum tiles with salt between them on springs settled over the first 3 months. Avoids a mess on scale pads and tires,prevents dirt fromcontaminating lube. RC Oval racing is probably the easiest form of RC racing right, right? What is Wedge in Dirt Racing? How Can it be Fixed? - Southern Reaceway Fans However, many cars cannot make the 50 percent left-side weight percentage due to driver offset. It puts power down better, and any decent FWD car will be carrying a wheel in the air around a turn anyway, so by default the outside rear gets 100% weight transfer when it's being asked to turn anyway. 2) Stagger: Stagger is how much bigger the right side tires are compared to the left side tires. Cross weight and left side work backwards in terms of adjustment. Here is a screenshot with some random-ass corner weights. Setting static weight distribution and adjusting cross-weight percentage is one way to assure good handling. Ask your chassis builder or establish what you want and decide that these will be what you run from now on. retract the right rear tire which puts more weight on the Left Rear and stiff springs on your coil overs. So if you have 60% on the front , you should have 30% on each front wheel. retract the right rear tire which puts more weight on the Left Rear and I use this technique and it Examine a modern push/pull rod suspension, particularly if it uses a crank link to transformthe Bounce the car at each corner to free the suspension from any bind, then roll the car onto the scales. in the driver's seat to load the suspension. Hub stands are a great idea just for ease of access, but removing friction is an added benefit. LR coil overs 2 1/2 turns. renting/borrowing/buying some scales and corner balancing your car. 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. Or it could also be possible that the signal is smoothed in the programming. If your car's diagonal corner weights are not equal then its handling will be 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. At the front, we will move the LF and RF adjusters up by 0.0625-inch. One of the keys to obtaining a good setup is using the correct procedure to weigh your race car. I used a laser level to project a horizontal I started out with the KW spring perches set exactly the same Wheel Offset Changes - Dirt Track Supply 6. "If your car is really tight or really loose during hot laps, you have to take a look at the things that are going to make the biggest difference. I race in a spec class, so everyone is using the same equipment. Or am I missing something? It is important that you complete the corner weighting process before doing an alignment. each and retract the RF (Right Front) and LR 1 1/4 turns each. 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). Since I went to 800 front and 700lb rear springs over the winter I Comet Kart Sales - Karting 101 - Getting Started in Kart Racing 4. The outer rear tire drives "around" the outer front tire, allowing the chassis to efficiently turn into the corner because the rear tire per wheel. I'm off by 0.1% (see numbers on left side of the spreadsheet). Wedge Delta can also be thought of 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 dual a-arm solutions, dead shocks can be used with springs and they can be built with much less bind out of the box. rear and tried again but I still needed more weight off the right front and left Shock Position Ok sounds good. turns. you run on the track. I plugged in a bunch of numbers into my calculator and it all checks out. Wedge is a term used in the After these items are completed, it is necessary to corner weight the car. This approach is commonly used in oval track racing. And don't ever believe the track scales. Choose your ride heights before you measure and/or redesign your front geometry and then maintain those chosen ride heights. These are only average measurements, and they will differ depending on the particular model of car that you have and the tires it is using. You can see the article here: And I cannot really move any weight around. of its weight on the Left Front and Right Rear tires, and 50% on the Right Front . How To Set Up RC Dirt Oval A Guide - Explained! We should now be at, or near, the desired crossweight percent. If you want to lower the ride height then retract both RF and First some baselines. This is my 2001 S2000 with 1/2 tank gas, 216 Take the total weight of the car in the configuration you decide on, with driver or without, and to find the corners, do the following: TVW = Total Vehicle Weight = 2,800, LSP = left side weight percent = 0.54, FWP = front weight percent = 0.51, CWP = Crossweight percent = 0.52. the scales and zero them with no weight on them. 3. In oval racing you always run more weight on the LR. I was surprised how much these high rate racers discovered they could insert an actual wedge into the left rear Once the corner balance is complete put someone in Same with go-karts with solid rear axles, they'll lift. In our example, move the LR and RR corners down by 0.4375-inch. Keep in mind the stiffer your springs the 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. Drag Racing. February 2017 -Suspension design process. If your car's diagonal corner weights are not equal then its handling will be unbalanced--it will turn better in one direction than in the other (all other things being equal). 57.5" front and 59.625" rear. All rights reserved. Toe inn a 1/4 inch. As an autocrosser I've always thought that cross weight should be set at 50% and be done with it. When a NASCAR crewchief says he's "adding wedge", 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. If you think you need to make crossweight changes, remember the amount of change per adjuster number, in our case it was 7/8 turns per percent of crossweight at the right sides (left sides again are times the multiplier), and make even percent changes, such as a half percent or whole percent. camber angle of the wheels (-3.5 front, -3 rear). anti-roll bar with the end-link adjusted so it's easy to insert the it would help the car turn left and accelerate better. Smaller will scrub less speed of if your not sideway threw the corner. My shocks are double adjustable, as many will be when at this level of prep. The coiloversare typically mounted parallel to the centerline above the driver footwell. shocks set to same length left to right (front to rear will be different). Our current setup is as follows - 270 lbs Car & Driver Cross Weight = 48% Rear Weight = 61% Left Side Weight = 51% LF = 56 lbs RF = 48 lbs LR = 82 lbs RR = 83 lbs You need to follow distinct directions to set up your RC for a dirt oval. racers only turn left we can balance the car for better grip in left 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. important for cars with upgraded (stiffer) sway bars because they can exert a The front will show close to 60%. The left rear link angles are less critical because that corner moves much less than the right side on asphalt cars. Caster creates stability as the geometry . Wedge Delta is equal to (Right Circle-Track Setup: What Is Toe, And Why Should You Use It? 3. tire pressure RF 43 LF 35 RR 40 LR 35 psi. You can ZJjtX0xiMzjbfb86GLC7qpXBkrSlFeSNVds8hGW514OXUKSxf6kBDIneIL3TzHQV. This was my first adjustment: Four turns of positive coil All of these factors play a huge part in what each corner of the car will weigh. 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. not to push it off the scales, to unload the suspension (as the car is To add weight to a given corner, raise the ride height at that corner or lower the ride height at an adjacent corner. 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. Cross Weight or Wedge. There are many ways to corner balance a car. Here is the method to correct the corner weights and set the left rear bite or cross weight. But if you corner and the inside wheel slows to 150rpm, the outside wheel will spin at 250rpm. Minimizing the hysteresis is good, but it also minimizes the shock/spring contribution to effective 'at the wheel' unprung weight (mass). front left and The LF needs to go up 0.3125 and the RF needs to go down the same amount. Suggested Adjustment Procedure for Oval Track - KONI NA (CG) height by using this online calculator: CG Height 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. If the car feels loose throughout the corner, lower both track bars evenly. If most of the important turns on your We will deal with preload on the bar later on. Setup Routine - JOES Racing Products Front + Left Rear) - (Left Front + Right Rear) and tells us how much Just make sure none of them are flat or wildly overinflated. 1 of the section on "Adjusting The Corner Weights," and that is 685. Afterward you need to adjust the settings to the correct maneuvers. 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. corner weight calculations: Corner_Balance.zip 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. 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. Are they adjustable? Oval racers favor left turns so they typically desire more weight Keeping track of Bite and You need a nice, flat and level surface for the scales. The advantage to wedge is that the left rear tire carries more load, so the car drives off the turns better. Or maybe I read the post wrong. Vehicle Scales | Corner Weight Race Car Scales - Speedway Motors I still rolled the car back and forth a More stagger usually loosens the handling in left turns, so more cross-weight is used to tighten it up. [ 1] In circle track racing, the use of the term "crossweight" gives us an indication of the weight distribution on the four tires. Then there is what I do for FWD stuff That is forget the rear weights entirely, and just balance the fronts to be equal. them for the corner balance. Even if you pay someone a small amount of money for their help, it will be far better than buying the scales yourself. I run generally 34F/30R for the street and usually (again depending on the day) drop the fronts to around 30~ and the rears to 26 or 28. to measure your new springs and put the longest spring in the left front--this The more rear weight bias, the tighter the chassis will be coming out of a turn. Put the driver weight in the car, preferably the driver. If your car has coil over adjustable shocks you should consider The more power a car has, the more that static weight over the drive wheels helps acceleration off the corners. 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. In April 2013 I corner balanced the S for the first time in If we remember, or record this number, then we can easily make changes in the future to get to our intended crossweight percent fast and easy. No, not as in the law, but in being legal in tech. height and the shocks set to the exact same spring perch height You need a nice, flat and level surface for the scales. The process is so basic to the setup of the car. By changing the weight distribution on the car, you affect the way your car will behave when cornering. Adjusting the sway bar is time consuming and questionable unless it is really stiff. Whats your SETUPS Dirt Track Racers? - Racing Forum - j-body The roll center is an imaginary point around which the rear of the race car rolls. We also take five rounds times the multiplier for the front of 1.25 5 = 6.25 rounds out of the LF. If you don't want to change your ride height then a more balanced approach would your scales. It will let you predict and understand the effects that various modifications have on handling, performance and lap times. Circle Track Analyzer - Performance Trends On the other hand, it drives really, REALLY good for being setup by this idiot behind the keyboard, and I really don't wanna spoil a good setup by chasing after a perfect setup at least not yet. The shock length as it is installed in the car at ride height. I put the car on the scales and input the four corner on the right front and left rear tires. intentionally favor a turn direction. Check stagger at each tire, even if using radials. for the front and rear sway bars and installed them with my girl friend sitting 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. Even 1/8 inch difference will make a difference, especially if you have section). If we are running twice as stiff a RR spring as the LR, we would need to change the height of the LR spring twice as much as the RR spring so that we don't affect the ride height as we hunt for the correct or desired weight distribution. Chassis FAQ | Hyper Racing You're better off not corner balancing the car than doing it on an unlevel Free Download Chapter listings from. unbalanced--it will turn better in one direction than in the other (all other How NASCAR Wedge Adjustments Work | HowStuffWorks Take the cosine of that angle, divide it into 1.0 and then square it, or multiply it by itself. 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. more traction or bite in left turns. Corner Weight | Go Ahead - Take the Wheel Dirt adds weight, binds suspension parts and hides potential problems > The bearings come well oiled and attract a lot of dirt. For a car with a 17.5-inch lower control arm length and a ball joint-to-spring mount distance of 2.5 inches, you divide 17.5 by 15 (17.5-2.5) to get 1.1667 and then multiply that by itself to get 1.3611. used linoleum tiles to shim two of my scales to get them all level. If you get the car neutral in left turns, it oversteers in right turns. Moving or removing weight is one Replacing a heavy battery with a light weight one allowed me to get close . Doing the multiplication to square that number, we get 1.1056. For now, we don't want the bar to influence the ride height or the weights we set later on. I see disconnecting the sway bar, and how to do it, but disconnect the shocks? (I suppose cooking oil, motor oil, KY, or Astro-Glide would also work). Once you have established an ideal moment center design and the correct cambers through testing, you need to maintain those throughout your season. coil over 5 turns. That makes every little detail that much more important. So, deviating from those numbers will mean you have a design other than what was intended for the car. Right Front weight: Left Rear weight: Moving weight to the front of the kart will provide more front-end grip. Find the difference from the desired average ride heights. I mainly run the 3/8. Adjust the cross weight for more extreme conditions or different circumstances. over Corner weights and chassis balancing - R/C Tech Forums work but in the end it's worth it. They're made by Proform, and are quite a bit less expensive than the ones made by Intercomp, but they got good reviews. To find LF weight: turn and ended up with a perfect 50.0% cross weight. The new existing ride heights are LF 3.6875, RF 4.8125, LR 4.1875, RR 5.3125. Check your tire pressure and bump it up to the hot pressure 2. Left front weight + right rear weight = right front weight + left rear weight. turn to the RF simply to raise the ride height of the front of the car. Record each spring rate. 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