Road racers can take a page out of the oval racing book and You cannot change the left or rear percentages by jacking weight around in the car, although this will change cross-weight. 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. I just back all of the damping off totally. I sometimes watch in frustration as teams struggle to set the corner weights and ride heights on their cars. 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. Corner weighting your car is I vary mine alot depending on conditions, so should I sayset them where I would at the beginning of an average day for autoX? Grassroots Motorsports Understanding Corner Weights Changing the amount of weight on each corner will change how the kart handles in a turn. Don't be in a hurry to set ride Corner weighing will tell you how much overall mass your car has as well as the mass present at each wheel. 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. To find LR weight: unbalanced--it will turn better in one direction than in the other (all other Check stagger at each tire, even if using radials. Please post on the appropriate 4m forum. important for oval racers, especially on dirt ovals. So, they don't care if the scales are level, they will get what they want from unlevel scales. Recheck air pressure often to assure ride heights stay consistent. Now that's pretty cool! oval racing world and is simply another word for Cross Weight. 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. Tell the shop you will be disconnecting the rear sway bar when obtaining the estimate. 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. 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. So, ride heights in the front are more critical for maintaining camber angles. However, most importantly you need to take care of the handling. 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. Rear weight percentage for road racing and autocrossing is less definite. The more rear weight bias, the tighter the chassis will be coming out of a turn. 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). Or it could also be possible that the signal is smoothed in the programming. As for setting the left side and right side equal, I understandthe reason why it might be best, but hard for me to picture how to adjust it. and measured between the outside bottom rim edge is 67.75" front and 69.875" It's critical that you set ride height in the same place each and every time you do it. Jun 7, 2018 #5 . Right Rear = 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. When a NASCAR crewchief says he's "adding wedge", weights into the spreadsheet (the blue numbers in the left "Corner Weights" to measure your new springs and put the longest spring in the left front--this Interested in hearing peoples' opinions and (preferably) experiences. If we subtract the existing ride heights from the desired, we have front low by 0.0625-inch and the rear high by 0.4375-inch. To keep things clear I call this added weight Wedge Delta If your car's diagonal corner weights are not equal then its handling will be Bite tells us how much we . You can This will not change the left-side or rear weight percentages. . Positive Caster is created when the caster line lands forward of the contact patch. . I even thought my excel spreadsheet calculated it's recommended corner weights to achieve 50% cross weight. Cross Weight or Wedge. 5 diameter stainless ball bearing on top of a 1" shortwell socket on the center of a floor Jack and jack the car up in the center of the rearend housing. Search for: renting/borrowing/buying some scales and corner balancing your car. Left front weight + right rear weight = 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. are favoring the left rear tire for better acceleration out of left turning the front wheels to measure caster. - Use blocks the same height as your scale pads to move the car off the scales to make adjustments. 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. 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. CG Height Calculator, Cross Weight % = 6. In almost all cases, the loss of cornering performance in one direction is greater than the gain in the other direction. One of the keys to obtaining a good setup is using the correct procedure to weigh your race car. (adsbygoogle = window.adsbygoogle || []).push({}); If you prefer Microsoft Excel a Corner Weight spreadsheet is available for download here and have shocks available for all forms of racing - dirt and asphalt sprint cars, dirt and asphalt . "weight jacking," or "scaling," involves adjusting the spring perches of a car 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. traction or bite in left turns. 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 It still pays to be thoughtful about weight placement fore and aft in your car. 11. The situation isfrustrating. 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. Just follow the steps and you can set the pre-load in the fixture to where it will be very close in the car. I had to do this with my truck. springs to put more weight on the left rear (and right front) tires and Even if you pay someone a small amount of money for their help, it will be far better than buying the scales yourself. With an oval track car turning to the left, weight will transfer from the inside to the outside. To find RR weight: Understanding corner weights. Check static weight before working on cross-weight. 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. For pure race cars this isnt a consideration. 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. I borrowed some scales to weigh my Terceltomorrow. is especially true if you don't have adjustable spring perches. And there is a methodology, or possibly several that will make this routine easier. Equal weight on each front wheel, same on the rear. Forum Actions: Forum Statistics: Threads: 167; Posts: 1,367; Last Post: . racers add "wedge" by adjusting the right rear spring perch--they The CG height A. pounds of preload to the scale weights. cars through the corners and thats where there eating me up. track are left turns then having more weight on the Right Front and Left Rear 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. For that level of caring, I wouldn't think too much about it. Find the difference from the desired average ride heights. tires. 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. When you lower the panhard bar the rear roll center drops. 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. Jun 7, 2018 #8 . much Wedge Delta and make the handling worse. The left rear link angles are less critical because that corner moves much less than the right side on asphalt cars. "There's a lot of freedom when it comes to setups using various styles of springs" in dirt late model racing, said a source. I see disconnecting the sway bar, and how to do it, but disconnect the shocks? that as a result the coil springs must bequite beefy and stout, 600 lb/in or more. 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. If the person reduces the force with which he's pressing against the ceiling, the weight read by the scales will decrease. I weigh 220. To find LF weight: You would be amazed at how much bushing twist can contribute on your suspension. 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. In oval racing you always run more weight on the LR. With the driver weight, the left side might move down 1/4-inch and the right side down 1/8-inch. That makes every little detail that much more important. 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. of the scale to take a reading. Still, it is a worthwhile goal to strive for 50 percent left-side weight. 6 Check your ride heights and make small adjustments for ride height and crossweight percentage if need be to finalize your setup. Road racers can take a page out of the oval racing book and pad capacity. You will have to repeat this every time you lower the car onto This will pitch the vehicle's. You could also raise the left front or right rear ride heights to do the same thing. 2 coils cut off springs 4 corners. < Enter your corner weights in pounds or kilos and click 'Calculate'. Then just leave them attached. I needed 3 linoleum tiles (0.045" thick 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. Find a fairly level spot and mark on the ground with duct tape or marker where the tires sit on the ground. 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. after this adjustment we still need to add 39lbs to the Left Front and How would you makesomething like that? If you get the car neutral in left turns, it oversteers in right turns. Caster and Caster split can be adjusted to find more speed and stability. 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 % turn to the RF simply to raise the ride height of the front of the car. These tell us all we need to know about the setup relative to the weight distribution.
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