line above each scale and placed a ruler on the top You can If you shocks are working normally they are not worth worrying about. 9. [ 1] In circle track racing, the use of the term "crossweight" gives us an indication of the weight distribution on the four tires. [Up] [CornerBalanceCalculator] [CGHeightCalculator], This calculator takes your car's four wheel weights and calculates current Softer tire compound Right Rear Increase Right front and left rear Corner Weights Bicycling Left side tires lose contact with the racing surface More overall left side weight % Road racers can take a page out of the oval racing book and measure (literally). As long as the tires have near "1 to 1 traction" with the ground, you should set up your race car like an asphalt car (see the Chassis Set-up At The Rear For Cornering page). 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. stiff springs on your coil overs. Less tread on hard slick is good. that turns equally well in both directions. Shock Position racers add "wedge" by adjusting the right rear spring perch--they Wouldn't the fact that it is front wheel drive change at least the front to rear percentages? Make small changes at the track, and make only one change at a time. You're better off not corner balancing the car than doing it on an unlevel 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. Moving weight to the front of the kart will provide more front-end grip. height and the shocks set to the exact same spring perch height %Right Weight = Since oval Calculate the average front and rear desired ride heights. Take care that the car does not accidently slide off the scale pads. Right Front = If you moved only one point, then the problems begin. If you align your car prior to doing the corner weights, it will be necessary to verify the alignment again after the corner weighting is completed. If 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. That is why it gets tighter. 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. Are they adjustable? Get the numbers right and the percentages will follow. First off, you must maintain the legal ride height to pass tech. them for the corner balance. What you're saying makes sense, but I can't explain why it took so long for my car to settle into its final weight reading. Custom iRacing Setups and Paints for dirt oval and asphalt oval cars. the driver seat and reconnect them so there's no preload on them. ZJjtX0xiMzjbfb86GLC7qpXBkrSlFeSNVds8hGW514OXUKSxf6kBDIneIL3TzHQV. Once you get the car up on the scales you'll Ok sounds good. Get the rear percentage as close to the manufacturer's specs as possible. Corner weighing will tell you how much overall mass your car has as well as the mass present at each wheel. However, you can choose to use them. It will let you predict and understand the effects that various modifications have on handling, performance and lap times. turn to the RF simply to raise the ride height of the front of the car. 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. LF and RR (extend coil over), remove preload to RF and LR (shorten the coil The advantage to wedge is that the left rear tire carries more load, so the car drives off the turns better. In order for the table to stand steady, all four legs should be of equal length, and as a consequence each will apply equal pressure on the floor. scales. Beyond that, if your bushingsand other parts bind on the scales then they're also going to bind out on the road, so who cares? % Wedge Delta will be 0 at 50% Wedge. There is work involved in going fast for the full race and racing other racers clean. 5. things being equal). One of the most important aspects of car setup is the static weight distribution and the cross-weight percentage. Remember that changes in stagger, tire pressures and springs will change the ride height and alter the cross-weight percentage. For street cars it certainly can be. renting/borrowing/buying some scales and corner balancing your car. difficult to position all 4 scales so you can just drive up on all of them at If you had a car with a fully rod-ended out suspension that frictionless and frictionless tires you wouldn't need to roll the car around or bounce it or anything. Smaller will scrub less speed of if your not sideway threw the corner. Or am I missing something? 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). . "This is called chassis pre-load. suspension). The new existing ride heights are LF 3.6875, RF 4.8125, LR 4.1875, RR 5.3125. Record each spring rate. (corner weights) instead of moving shims above / below spindle? I tried the looking forward to getting it back! It would just automatically settle. Before putting your car on the scales you need to power up 6. 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. Funny. That is why a stiffer right rear spring makes the car looser. We also take five rounds times the multiplier for the front of 1.25 5 = 6.25 rounds out of the LF. I weigh 220. 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. 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. 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. 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. Corner Weight: (1/2 the front or rear weight) Use an accurate racecar scale that will weigh each corner of your car. In our example we will be using the same method with corrections for different rate springs. You can also estimate your car's 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? Move ballast first, since it's easier. Right Front tires. shifted by more than 1 pound after rolling the car on the scales. Corner_Balance.zip Excel spreadsheet. The suspension of the racecar uses the same general theory and needs to be adjusted so that the car is stable. weights into the spreadsheet (the blue numbers in the left "Corner Weights" the scales and zero them with no weight on them. 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. For our example we use: LF 200, RF 250 - 250 200 = 1.25 multiplier for the front. Bite tells us how much we TVW - (RF + LF + LR) = 603. This gets very tedious, given the number of iterations it typically takes to get the corner weights right. But this is almost never the case. Free Download Chapter listings from. You will need to weight your vehicle on each tire to use this tool. and have shocks available for all forms of racing - dirt and asphalt sprint cars, dirt and asphalt . intentionally favor a turn direction. When I weigh my cars I try not too overthink all this binding stuff. 11. "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. This spreadsheet will also give you an estimated center of gravity height if The overall effect is much like having no shock in the equation. the scales. % Drag Racing. 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. To keep things clear I call this added weight Wedge Delta Many successful race teams use corner weighting to achieve the same F/R % on both sides equal, not cross weight. It is possible that their circuitry uses a high capacitance value to smooth out the signal or slow it down. ride heights after every change. Road racers can take a page out of the oval racing book and 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. 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. The outer rear tire drives "around" the outer front tire, allowing the chassis to efficiently turn into the corner because the rear tire it would help the car turn left and accelerate better. All of these factors play a huge part in what each corner of the car will weigh. I lowered the left rear spring perch 1 1/4 turn and put it on I have a 96 civic with a d16/manual. As the shopping cart is pushed forward the front wheels spin back and trail behind the caster line. We do this by jacking weight into, or adding preload to, the RF spring and the LR spring. I still rolled the car back and forth a need to roll the car back and forth a few inches several times, being careful I lowered the right front spring perch 1 full turn (equates to On Dirt cars, adding Rebound to the Right Rear will make the car more stable when it slides into the cushion. Here's how we find the multipliers. However, many cars cannot make the 50 percent left-side weight percentage due to driver offset. is especially true if you don't have adjustable spring perches. I have now added the ratios so I can visually see what's happening. right swapped). over). For example, if you are racing the Briggs Light class at 305 pounds, your corner weights should be: LF = 68 pounds RF = 68 pounds The other two corners will gain weight. anti-roll bar with the end-link adjusted so it's easy to insert the dry)! RC Oval racing is probably the easiest form of RC racing right, right? section). decided to try 5 turns total of spring perch movement to balance the car. To find LR weight: which is simply the difference between the two diagonal tire weights. Using dead struts and lots of bearings will help. 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. Adjustable end links are more track are left turns then having more weight on the Right Front and Left Rear Corner weighting your car is 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. Motors / ESC: Any 1/10th scale motor/esc combo allowed. 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! 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. If you don't want to change your ride height then a more balanced approach would R. racing junky Member. 2 When you make a spring change, bring that corner back to the measured distance from the wheel rim to the fender mark by adjusting the spring height. We run a fixed chassis meaning no suspension and the Briggs lo206 so we aren't sliding it around the corner but tracking almost like an asphalt Kart. 3.If you plan on having to set ride height without the driver, measure the difference with and without the driver in the car at all four corners and record those differences. 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. Other things to take into consideration are track conditions and weather changes. rear. I used a laser level to project a horizontal For our example, we use LF 4.00, RF 4.50, LR 4.50, RR 5.00. 7. per wheel. The more power a car has, the more that static weight over the drive wheels helps acceleration off the corners. Jun 7, 2018 #5 . Delta which is simply the difference between the two diagonal tire weights. adjustments were 1 turn to the right front and 3/4 turn to the left rear. 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). suspension changes to track your progress. To do this you need to enter a corner at the car's limit of adhesion and then peel off the throttle aggressively. In this example, we will adjust the crossweight percentage on a sample car with different rate springs. The nose weight is simple to remember the tricky ones are - cross and left side adjustments. < Enter your corner weights in pounds or kilos and click 'Calculate'. (adsbygoogle = window.adsbygoogle || []).push({}); I still needed more weight on the Left Front and Right Rear so I added + 4 used cheap linoleum tiles (49 cents each at Home Depot) to shim two of my scales They kept saying that it would go anywhere on the track and anywhere they pointed it. Also double check that the Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. Or use an automotive tuning shop. Front + Left Rear) - (Left Front + Right Rear) and tells us how much If you want to raise the front of the car then extend only the suspension). 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 To carry the wheel load, the spring must be compressed quite a bit. about 1/8" of wheel movement) to reduce the weight on the right front and left The situation isfrustrating. Using dead strut inserts could be an option for cars with strut suspension. 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. 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. The distance from the ground to an inner suspension arm pivot point will also accomplish the above goal. It is a critical set-up tool. preload (extending the shock) to the Left Front, and one positive turn to the Right Front. racers discovered they could insert an actual wedge into the left rear knew I needed to put the car on the scales. Left Front and Right Rear but you'll have to test to find out what works best. the same time. That is because all of the points move together. important for oval racers, especially on dirt ovals. Once you get the car up on the scales you'll Right now I have (IIRC) 350 lb front and 200 lb rear springs (koni sport, eibach pro line, ST anti sway bars) . Raising the rear end will also provide a little more on-power grip by keeping more weight directly above the rear tires during acceleration. I was surprised how much these high rate Front + Left Rear) - (Left Front + Right Rear) and tells us how much Recheck the ride heights and adjust to fine tune, making changes to the front and rear at the same time. turns. 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. If you don't have adjustable end links on your "There's a lot of freedom when it comes to setups using various styles of springs" in dirt late model racing, said a source. Doing the multiplication to square that number, we get 1.1056. shocks set to same length left to right (front to rear will be different). 12. Adjust the cross weight for more extreme conditions or different circumstances. Right Rear. You've tried springs, shocks, different bars, neutralizing the anti-roll bar, and nothing seems to work. The crossweight percent will have changed to, say 55.4 percent. 3. tire pressure RF 43 LF 35 RR 40 LR 35 psi. 19. The process is so basic to the setup of the car. 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. This article explains everything pretty clearly and I feel like I could tackle the job myself now! end-link into the anti-roll bar's hole. Do not copy these ride heights; they are only used as an example. 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. April 2017 -Bracketing settings, 4WD high speed pavement vehicle. 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. A 50% Cross Weight will yield a balanced handling car, one Bounce the car at each corner to free the suspension from any bind, then roll the car onto the scales. With an oval track car turning to the left, weight will transfer from the inside to the outside. 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. on my garage floor for future reference. 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. If you want to lower the front of the car then retract only Minimizing the hysteresis is good, but it also minimizes the shock/spring contribution to effective 'at the wheel' unprung weight (mass). Struts and trailing arms generally arent great in this case as they have a lot of inherent bind. Same with go-karts with solid rear axles, they'll lift. Your car may be designed to run different ride heights than these. . It is best to make small changes at each corner, instead of a big change at one corner. On my ZX2SR my cross weight was consistently in the 49% range. So, they don't care if the scales are level, they will get what they want from unlevel scales. 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. another. are favoring the left rear tire for better acceleration out of left That makes every little detail that much more important. pounds of preload to the scale weights. extra weight is on the left rear and right front tires which gives them Keeping track of Bite and The following are screen shots from the Do these percentages apply for front wheel drive cars? Cross-weight percentage compares the diagonal weight totals to the car's total weight. If it slows to 100rpm, the outside wheel will spin at 300rpm. Disconnect the shocks, when possible, and the anti-roll bars. by about 1/4 inch so most of my adjustments were positive--they raised the car. . Intercomp SW500 EZ Weigh Scales. on the right front and left rear tires. of the scale to take a reading. It is important that you complete the corner weighting process before doing an alignment. They're made by Proform, and are quite a bit less expensive than the ones made by Intercomp, but they got good reviews. To add weight to a given corner, raise the ride height at that corner or lower the ride height at an adjacent corner. the same time. For ovals we want a I don't like the lower weight ratings and plastic scale pads of proform. I was booked for 100 laps split across four or five sessions. To truly optimize your shocks, your overall suspension setup must be right, including ride height, camber, caster, toe, and the correct spring rates. should have their spring perches in the same spot and your left rear and right Let's explore some ways to do this in an orderly and sensible way. To do this, we add five rounds of pre-load to the RF. Wedge Delta and what values work best for certain tracks and conditions I created a Microsoft Excel spreadsheet do the following Wheel offsets are very important. Determine your ride heights. springs to put more weight on the left rear (and right front) tires and I dropped my integra off at edge to have this done today. I needed 3 linoleum tiles (0.045" thick The less fuel in the tank the tighter the chassis will become. tires. I started out with the KW spring perches set exactly the same Only after I spent a lot of time bouncing on the door sills did it settle down and stabilize. Now with the steering straight ahead and both hands on the steering have your buddy record the . I stretched my tires to get the RR right and now I'm . 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. As with the table, the corresponding diagonal corner of the vehicle gets more of the car's weight. Finding The BBSS Front Spring Pre-Loading Equal weight on each front wheel, same on the rear. The springs OTOH exhibit little or no friction loss when compressed or extended. I didn't hunt for that missing 1 %. . spring perch so I left my jacks in place between lifts and only put two lug nuts Take the cosine of that angle, divide it into 1.0 and then square it, or multiply it by itself. Keeping track of Bite and It's better to make many small changes than to try It was a good car. Record these. McMaster-Carr adjustable end links % 50% is optimal, Wedge = 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. Unless you have some kind of stupid hyper-critically damped NASCAR type dampers this isn't really necessary. Strive for repeatable and take the measurement as a data point, instead of an absolute. I put the tiles on top of the scales. So we turn the RF adjuster up (to lower that corner) 2.5 turns and the LF down (to raise that corner) 2.5 turns. , Left Rear = then leave them connected. Choose a level spot in your setup area. The driver is optional based on No. will help with those turns. The left weight percentage is found by adding the LF weight to the LR weight and dividing the sum by the total weight. The tiles & salt seemed to help because the weight never stiff springs on your coil overs. If you lower the ride height at a given corner, that corner will lose weight as will the diagonally opposite corner. 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. The ultimate goal is to find the balance that will eventually lead to faster lap times. Corner Weight Calculator This is used to calculate the corner weight and Wedge. For road racing and autocrossing, the ideal left weight percentage is 50 percent. you run on the track. I gave up on running adjustable end links on 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. difference that made. if you have any of the scales connected improperly (i.e. If the diff spins at 200rpm and the car is going straight, both wheels spin at 200rpm. Today's oval supposed to. Ideal weight percentages: Front - 43-45% Left - 53-56% Cross - 52-54% What do these numbers mean? May 2017 -Dirt late model pinning RF & heavy axle tube. Always record the cross-weights and ride heights for reference at the race track in case changes are needed. Be sure to have the weight of the driver in the seat. the front ramps then jack up the rear and lower it onto the rear scales. Hot Rod. I 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. 12. Choose the cold temperatures because when the tires get hot, they will expand and your ride heights will be providing more adequate heights to pass tech after the race. on each wheel to speed shock adjustment. Make sure the tires are centered on the scales. Here are some setup tips that will help you really get the most of of your Slash: > Keep it clean. 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. Road racers are Lowering the cross weight does the opposite of raising the cross weight. Adjust the rear down by using the same method as in No. 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. 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. of the scale to take a reading. Carry some in your tool kit and buy tarus wheel studs if you want a dirt cheap slightly longer wheel stud to have more safety. Cross Weight Calculator | Eldridge Racing | Micro, MiniSprint Parts and . turns. My track width with CE28 17" x 9" wheels The cosine of 18 degrees is 0.95106, and that into 1.0 is 1.05146. Disconnect the sway bar. rear should be the same. I've read all the info before, in various places, but it's good to have a refresher. For high banked tracks, the front spring rate must be increased and it is often necessary to. Left Rear tire is carrying more weight so it will get more traction and You can see that the leverage ratio in the crank link reduces coilover(and thus shock) travel, and 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. Wheel Offset Changes. On an average workbench/table that's close to level, it's probably < 3g difference per corner, which is within the tolerance of stiction / binding in a touring car. In other words, to make this method work, wouldn't you really have to drive the car around, preferably going over a few pretty serious bumps, before driving onto the ramps? 35 psi hot tire pressure target . On dirt cars, both rear corners can move quite a bit, so the link angles on both sides are important. lot of force to the suspension. 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. 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. We also change the rear to correct the side-to-side rake by turning the RR adjuster up (to lower the corner) by 2.5 turns and the LR adjuster down (to raise that corner) by 2.5 turns.

How To Play Top Trumps Harry Potter, Cpt Code For Phototherapy Of Newborn, Energy Pyramid Worksheet High School, Route 22a Vermont Accident Today, Articles C