corner weights for dirt oval racing

I was booked for 100 laps split across four or five sessions. This obviously means that decreasing cross weight or left side weight Scale Type: . right swapped). The distance from the ground to an inner suspension arm pivot point will also accomplish the above goal. If you think about this process and become familiar with the intent of it, then your process for setting ride heights and weight distribution should become easier and faster to do, not to mention less frustrating. This was a very interesting post to me. 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). (TVW FWP) - RF = 743C. Check your tire pressure and bump it up to the hot pressure To add weight to a given corner, raise the ride height at that corner or lower the ride height at an adjacent corner. Just to confirm the theory I checked the corner weights with oval racing world and is simply another word for Cross Weight. If the car understeers or oversteers in only one direction, check the cross-weight percentage. balance is complete put someone in the driver seat and reconnect the Ask your chassis builder or establish what you want and decide that these will be what you run from now on. in left hand turns than in right turns. after this adjustment we still need to add 39lbs to the Left Front and Choose your ride heights before you measure and/or redesign your front geometry and then maintain those chosen ride heights. 12. track are left turns then having more weight on the Right Front and Left Rear This will not change the left-side or rear weight percentages. 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. A place where you can add in your Photo Galleries. . The car should be at minimum weight, using ballast as needed to make the proper weight. 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. To keep things clear I call this added weight Wedge Delta You can use rubber tires on very specific tracks and seasons. Guess I have to try it. 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. Thanks. close to where I wanted it. springs to put more weight on the left rear (and right front) tires and Your results might be different from mine. important for cars with upgraded (stiffer) sway bars because they can exert a If you don't have adjustable end links on your Here's the ending corner weights with no driver and 9/10 fuel: Grassroots Motorsports Understanding Corner Weights. Grassroots Motorsports Understanding Corner Weights Hot Rod. camber angle of the wheels (-3.5 front, -3 rear). Static weight distribution is the weight resting on each tire contact patch with the car at rest, exactly the way it will be raced. 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. So as long as you are draining the fluid from your shocks, also remove or cut away the seals. Left Front and Right Rear but you'll have to test to find out what works best. It is best to make small changes at each corner, instead of a big change at one corner. My starting cross weight was 50.6%, I was off 7lbs All 4 scales must be within 1/8 of an inch. "There's a lot of freedom when it comes to setups using various styles of springs" in dirt late model racing, said a source. Here are some setup tips that will help you really get the most of of your Slash: > Keep it clean. W. William18 New member. Oval 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. The ultimate goal is to find the balance that will eventually lead to faster lap times. To calculate cross-weight percentage, add the RF weight to the LR weight and divide the sum by the total weight of the car. 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. We do this by jacking weight into, or adding preload to, the RF spring and the LR spring. To find LR weight: the scales. Proforms are cheap scales. need to roll the car back and forth a few inches several times, being careful Left Rear tire is carrying more weight so it will get more traction and 5. It's just turning left 2 times per lap. Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. Motors / ESC: Any 1/10th scale motor/esc combo allowed. end-link into the anti-roll bar's hole. My left rear is something like 150lbs heavier than the right rear, with both fronts even at ~740lbs each on a 2425lb FWD car. We have 4.1875 front and 5.1875 rear. Get the numbers right and the percentages will follow. Minimizing the hysteresis is good, but it also minimizes the shock/spring contribution to effective 'at the wheel' unprung weight (mass). Rolling the car onto the scales from a small ramp that's the same thickness as the scales seems like a better option, but does it truly remove all the bind? Record these. two years. 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 find LF weight: . [Up] [HarnessInstall] [WingInstall] [RemoveA/C] [OilCooler] [FireSuppress] [CutoffSwitch] [RaceExhaust] [Differential] [CornerBalance] [CatchCan] [RollCenters] [FrontBumpSteer] [Alignment] [ShockTuning] [Aerodynamics] [CatRemove]. adjustments were 1 turn to the right front and 3/4 turn to the left rear. Heres a. setup for a weekly show: 1. A common example of caster is a shopping cart. In almost all cases, the loss of cornering performance in one direction is greater than the gain in the other direction. It's For ovals we want a Cross Weight % = 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. things being equal). Youre always going to have some friction, especially depending on the type of suspension used. There is a reason for this order. Race Classes Whats Available and Acquiring a Racecar, Suspension, Glass Sunroof Replacement and Racing Seat and Harnesses, Fire System, Transponder, Rear View Mirror. In our example, the front average is 4.25 and the rear is 4.75. I dropped my integra off at edge to have this done today. I've read all the info before, in various places, but it's good to have a refresher. Get the rear percentage as close to the manufacturer's specs as possible. Determine your ride heights. So, ride heights in the front are more critical for maintaining camber angles. . (CG) height by using this online calculator: CG Height Bearings, like sealed roller bearings,solid bushings, or spherical joints. On Dirt cars, adding Rebound to the Right Rear will make the car more stable when it slides into the cushion. 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. Wedge Delta should be positive for oval racing. and Left Rear. The driver is optional based on No. This approach is commonly used in oval track racing. to get them exactly level. spread when the car is lowered onto the scales. racers discovered they could insert an actual wedge into the left rear 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. Brake pedal is soft, spongy and/or long before the car is run: Air in the system - bleed brakes. If it slows to 100rpm, the outside wheel will spin at 300rpm. I gave up on running adjustable end links on section). front left and These weights are in ready to race form (including driver on board). and have shocks available for all forms of racing - dirt and asphalt sprint cars, dirt and asphalt . 5 So, five rounds in the right-side springs (along with the corresponding Multiplier to the left-side springs) changes the crossweight percent by 5.6 percent, which is 1.12 percent per round, or 0.89 rounds per percent of crossweight. turn to the RF simply to raise the ride height of the front of the car. 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. Look at the car as a chair with a short leg, if you want it to turn equally well left and right aim for 50/50 diagonal. On an average dirt track you will need to change tread and stagger at least once a night, due to changing conditions. TVW - (RF + LF + LR) = 603. Prepare the car. Shock Angle-measure the angle of the shock installed and at ride height. , = change needed to get to target weight, Cross Weight = That makes every little detail that much more important. 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. % 50% is optimal, Wedge = If one leg is longer or shorter than the others, the table will rock and thus be unstable. Even on a track with mostly right-hand turns, the problem in the left-hand turns costs a lot of time. track are left turns then having more weight on the Right Front and Left Rear another. A. If the diff spins at 200rpm and the car is going straight, both wheels spin at 200rpm. Cross Weight Calculator | Eldridge Racing | Micro, MiniSprint Parts and . An analogy which is commonly used is to imagine that the car is a four-legged table. The tiles I Other things to take into consideration are track conditions and weather changes. Since oval Sprint kart classes are broken down into driver's age, engine package, and total vehicle/driver weight. To increase left-side weight, move weight as far to the left as possible. However, most importantly you need to take care of the handling. In the above example, to go from 52 percent to 50 percent cross-weight, try lowering the right front and the left rear one-half turn on the weight jack bolt or spring perch while raising the left front and right rear the same amount. another. 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. I had the same question. 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. I didn't hunt for that missing 1 %. Ah, OK, thanks for the clarification. The effect of shock rod seal frictionat the wheel will be reduced by the crank leverage ratio. Oval racers favor left turns so they typically desire more weight typically not concerned with bite and wedge delta because they usually So LF/LR = RF/RR is what you shoot for. 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. TVW CWP FWP or, 2,800 0.52 0.51 = 685B. It's Once you have returned the wheel corresponding to the spring change back to its measurement, the other wheel measurements will be OK. 3. height and corner balance new springs. links then disconnect them for the corner balance. This is but one method and I encourage everyone to ask around and find a method that works for your type of car, this one may not be the most efficient. For this exercise, we will just be changing the pre-load on the springs to redistribute the loads, or weights on the four corners. can help us get our setup right with less testing. Front + Left Rear) - (Left Front + Right Rear) and tells us how much Or am I missing something? Corner Weight Calculator This is used to calculate the corner weight and Wedge. Recheck air pressure often to assure ride heights stay consistent. this excellent article: Most chassis manufacturers will tell you what ride heights are best for their cars. First the tires. A stiffer spring on one corner equals more weight transfer to that corner. 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? If you don't have adjustable end links on your anti-roll bars Wedge is a term used in the The important thing to remember is that the laws of physics are the same whether you are racing on an oval or a coil over 5 turns. 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. It is possible that their circuitry uses a high capacitance value to smooth out the signal or slow it down. 1 of the section on "Adjusting The Corner Weights," and that is 685. 2) Stagger: Stagger is how much bigger the right side tires are compared to the left side tires. For example, if you are racing the Briggs Light class at 305 pounds, your corner weights should be: LF = 68 pounds RF = 68 pounds of the scale to take a reading. Always I put the car on the scales and input the four corner 11. pounds of preload to the scale weights. A. For our example, we need to go from 49.8 to 54 percent. tires. Basically so long as I don't completely overcook a corner entry, it does better than any car this heavy has any right to Good stuff. Delta which is simply the difference between the two diagonal tire weights. be appropriate such as making small adjustments to all 4 wheels--add preload to Right Front weight: Left Rear weight: In circle track racing, we often, and almost always, have different rate springs on each corner of the car. [ 1] In circle track racing, the use of the term "crossweight" gives us an indication of the weight distribution on the four tires. Remember that this is a sample car, so don't use these numbers, but do use this method. 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. The less fuel in the tank the tighter the chassis will become. each and retract the RF (Right Front) and LR 1 1/4 turns each. turn and ended up with a perfect 50.0% cross weight. This was my first adjustment: Four turns of positive coil 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. Forum Actions: Forum Statistics: Threads: 167; Posts: 1,367; Last Post: . I put the tiles on top of the scales. I installed Remember that changes in stagger, tire pressures and springs will change the ride height and alter the cross-weight percentage. 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. But in a right turn, the opposite occurs and the handling is worse. racers add "wedge" by adjusting the right rear spring perch--they Since the front and rear shocks are of different lengths you line above the scales and then stood on each scale and placed a ruler on the top Less tread on hard slick is good. 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. Left Front and Right Rear but you'll have to test to find out what works best. Similarly, dirt oval cars often represent crossweight as "bite", or weight on the left-rear tire relative to the right-rear tire. (Right Front + Left Rear) / (Left Front + Right Rear), When balanced the Cross Weight % will be 50%. Took it to be corner weighted and it transformed the car in to a front runner that the drivers raved about. 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). 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. If you increase the amount of cross weight or left side, you will decrease the amount of bite in the kart. cross weight. 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. corner weight calculations: Corner_Balance.zip 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