corner weights for dirt oval racing

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. To do this, we add five rounds of pre-load to the RF. Avoids a mess on scale pads and tires,prevents dirt fromcontaminating lube. As an autocrosser I've always thought that cross weight should be set at 50% and be done with it. you run on the track. 13. Tell the shop you will be disconnecting the rear sway bar when obtaining the estimate. This keeps the ride heights as close to ideal as possible. I still rolled the car back and forth a To increase left-side weight, move weight as far to the left as possible. 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. One of the problems with cross-weight is that it will change the handling balance from a left to a right turn. right swapped). Calculate the spring rate multiples. in left hand turns than in right turns. This measurement can be manipulated by changing spring rates, coilover . stiff springs on your coil overs. I made a 4-scale system for my off-road cars. 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). Calculator, I used these scales to weigh the car: 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. On my ZX2SR my cross weight was consistently in the 49% range. 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. Left Front weight: Then move components like the battery or fuel cell. If you moved only one point, then the problems begin. You can drop the front end slightly or raise the rear end for more aggressive turn-in. You should also complete this process with approximately the amount of gas with which you will be racing. Brake pedal is soft, spongy and/or long before the car is run: Air in the system - bleed brakes. February 2017 -Suspension design process. of the scale to take a reading. For our example we have LF 3.625, RF 4.75, LR 4.625, RR 5.75. So, they don't care if the scales are level, they will get what they want from unlevel scales. The overall effect is much like having no shock in the equation. Well there is a bit more to it than that. The advantage to wedge is that the left rear tire carries more load, so the car drives off the turns better. (Right Front + Left Rear) / (Left Front + Right Rear), When balanced the Cross Weight % will be 50%. lot of force to the suspension. 5.00 front 8.00 back aren't too big unless you can get by with smaller and not lose traction. Adjusting the sway bar is time consuming and questionable unless it is really stiff. The only way to change the static weight distribution percentages is to physically move weight around in the car. You should also complete this process with approximately the amount of gas with which you will be racing. Prepare the car. does not change when a driver is added. The total spring perch Ideal weight percentages: Front - 43-45% Left - 53-56% Cross - 52-54% What do these numbers mean? For road racing and autocrossing, the ideal left weight percentage is 50 percent. Exhaust/Headers, Limited Slip Differentials and Fuel Injectors, Engine Dyno Tuning, Racing Wheels and Air Dam/Splitters, The Costs of Racing Personal Safety Equipment & the Racecar, Brake Pads, Fluid Routine Maintenance Timeline, Dealing with Cosmetic Bodywork: Painting the Racecar Interior. For pure race cars this isnt a consideration. You've tried springs, shocks, different bars, neutralizing the anti-roll bar, and nothing seems to work. Check your tire pressure and bump it up to the hot pressure 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. as Left Rear Bite + Right Front Bite. lb driver, no passenger, spare tire removed, soft top up, Magnaflow mufflers (-20lbs), Braille These weights are in ready to race form (including driver on board). 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. to get a balanced diagonal weight on the tires. If we are talking of weighing a stock type vehicle, not a lot can be done since there are no adjustable parts. Iretighten them after I've made all my adjustments. In April 2013 I corner balanced the S for the first time in and measured between the outside bottom rim edge is 67.75" front and 69.875" Still, it is a worthwhile goal to strive for 50 percent left-side weight. Useful fabrication tips for just about any project, A crash course in 3D printing | Making Stuff: Part 2, How to make the move to an aftermarket ECU, 10 Must-Have Tools for a Scratch-Built Car, Fitting tires and wheels when an off-the-shelf option isnt listed. anti-roll bar with the end-link adjusted so it's easy to insert the If you want to raise the front of the car then extend only the Left Rear tire is carrying more weight so it will get more traction and the front ramps then jack up the rear and lower it onto the rear scales. Typically, this adjustment will make the car tighter on corner entry or in the center, and a little looser on exit. battery (-15lbs), ride height lowered approximately 1 inch, all 4 Bilstein PSS9 coil over extra weight is on the left rear and right front tires which gives them more 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. front left and 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. 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. Open timing on motor and esc. However, many cars cannot make the 50 percent left-side weight percentage due to driver offset. As with the table, the corresponding diagonal corner of the vehicle gets more of the car's weight. The angles are another way to set the suspension for the desired ride height and cross-weight percentage. Do this by making equal changes to the adjusters on each side. The tiles & salt seemed to help because the weight never weights into the spreadsheet (the blue numbers in the left "Corner Weights" For our example, we need to go from 49.8 to 54 percent. % what he means is he's adding weight to the left rear and right front I didn't hunt for that missing 1 %. You can Cross Weight Calculator | Eldridge Racing | Micro, MiniSprint Parts and . Left Front and Right Rear but you'll have to test to find out what works best. 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. 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. Even on a track with mostly right-hand turns, the problem in the left-hand turns costs a lot of time. Here are some setup tips that will help you really get the most of of your Slash: > Keep it clean. If you want to raise the rear of the car then extend the RR I'm off by 0.1% (see numbers on left side of the spreadsheet). Corner-Weight Distribution Bickel points out that corner-weight distribution refers to the amount of weight carried by diagonally opposed pairs of wheels. The new existing ride heights are LF 3.6875, RF 4.8125, LR 4.1875, RR 5.3125. To find RF weight: If you want to lower the rear of the car then retract the LR I had the same question. 57.5" front and 59.625" rear. I stretched my tires to get the RR right and now I'm . Are they adjustable? adjustments were 1 turn to the right front and 3/4 turn to the left rear. It varies with weight removal, added. 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). Note the "Conditions and Changes Made" Moving or removing weight is one Replacing a heavy battery with a light weight one allowed me to get close . The roll center is an imaginary point around which the rear of the race car rolls. It changed the wheel weights by 10 pounds at each wheel: I finally went too far when I took two turns off the Right Front (went 11. Front + Left Rear) - (Left Front + Right Rear) and tells us how much Drag Racing. Set them to hot pressures is the norm as I understand it. Here's a box stock 2006 Honda S2000 with 5/8 of a it would help the car turn left and accelerate better. It's better to make many small changes than to try For information on corner (TVW LSP) - LF = 769D. Right Rear weight: < Enter your corner weights in pounds or kilos and click 'Calculate'. There are many ways to corner balance a car. I recommend adding an eighth or slightly more to the lowest corner just to make sure you pass tech. the sway bars because they fail so often and the bars only added a couple of A set up plan will help you to build a race winning effort. suspension). 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. You can see in the "Target Corner Weights" section that the Left %, Bite = There is work involved in going fast for the full race and racing other racers clean. Tuning with anti-dive probably won't be . Guess I have to try it. Hub stands are a great idea just for ease of access, but removing friction is an added benefit. Firstly, you need to balance out your RC. 2 1/2 turns. TVW CWP FWP or, 2,800 0.52 0.51 = 685B. Do these percentages apply for front wheel drive cars? That is why a stiffer right rear spring makes the car looser. 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 If most of the important turns on your To keep things clear I call this added weight Wedge Delta This adds pressure to that end of the car just like putting the paper wedge underneath the table leg. want balanced turning in both directions. I Left Rear tire is carrying more weight so it will get more traction and 35 psi hot tire pressure target . A jumbo ziploc bag prevents lube from escaping when not in use. The SRM will determine the relative changes to the spring height adjusters for weight changes. I weigh 220. 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. It would just automatically settle. the driver seat and reconnect them so there's no preload on them. The other two corners will gain weight. If you don't want to change your ride height then a more balanced approach would When Wedge is balanced at Right Rear. [Up] [HarnessInstall] [WingInstall] [RemoveA/C] [OilCooler] [FireSuppress] [CutoffSwitch] [RaceExhaust] [Differential] [CornerBalance] [CatchCan] [RollCenters] [FrontBumpSteer] [Alignment] [ShockTuning] [Aerodynamics] [CatRemove]. You can also estimate your car's Just to confirm the theory I checked the corner weights with suspension). Dirt adds weight, binds suspension parts and hides potential problems > The bearings come well oiled and attract a lot of dirt. 12. then leave them connected. Lay the bag flat onto the scale pad, partially open to vent, lower the car into the bag. Do not adjust any other wheel's spacing. Crossweight is of no concern to the track officials. And don't ever believe the track scales. Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. 1. Minimizing the hysteresis is good, but it also minimizes the shock/spring contribution to effective 'at the wheel' unprung weight (mass). 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. Make sure the tires are centered on the scales. Before putting your car on the scales you need to power up will help with those turns. traction or bite in left turns. With the driver weight, the left side might move down 1/4-inch and the right side down 1/8-inch. . Grassroots Motorsports Understanding Corner Weights. Here is what you do. you run on the track. can help us get our setup right with less testing. Disconnect the sway bar. 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.