Tire stagger | Bob's 4 Cycle Karting Even on a track with mostly right-hand turns, the problem in the left-hand turns costs a lot of time. Caster creates stability as the geometry . Right Front = rear should be the same. you run on the track. My starting cross weight was 50.6%, I was off 7lbs Same with go-karts with solid rear axles, they'll lift. The following weights are with the front Comptech adjustable Interested in hearing peoples' opinions and (preferably) experiences. another. 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. I'm off by 0.1% (see numbers on left side of the spreadsheet). Race Tires: Are You Ready to Spend Some Money? I dont get this. Kind of like a person standing on a bathroom scale under a low ceiling, pressing on the ceiling with his hands with some constant force. 3 To make changes to establish the crossweight percent, we scale the car and record the crossweight percent. Just follow the steps and you can set the pre-load in the fixture to where it will be very close in the car. more traction or bite in left turns. Bite tells us how much we Motor: 550 or 540 motors only. Check your tire pressure and bump it up to the hot pressure Wedge Delta can also be thought of Typically, a road racing car should have 50% Wouldn't the fact that it is front wheel drive change at least the front to rear percentages? Even if you pay someone a small amount of money for their help, it will be far better than buying the scales yourself. the front ramps then jack up the rear and lower it onto the rear scales. Before putting your car on the scales you need to power up I painstakingly leveled the scales and marked their locations Kart racing chassis are designed in a manner to allow it to turn the only way it can, without having a read differential - with the inside rear tire lifting off the track on corner entry. 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. Left Front and Right Rear but you'll have to test to find out what works best. If you want to raise the rear of the car then extend the RR 3. this excellent article: Adding more rebound to the car will make the car more stable on rougher tracks. Crossweight is of no concern to the track officials. Motion Ratio of the lower control arm. cross weight - iRacing.com Wiki This measurement can be manipulated by changing spring rates, coilover . Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. You will have to repeat this every time you lower the car onto scales are connected properly--you can really screw up your suspension settings turn and ended up with a perfect 50.0% cross weight. Check static weight before working on cross-weight. How To Set Up Your Car for Oval Track Racing - RacingJunk News balancing see my corner balance how-to and Setup Routine - JOES Racing Products There's Nothing In Racing Simpler-or Harder-Than Driving a Sprint Car 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. each and retract the RF (Right Front) and LR 1 1/4 turns each. extra weight is on the left rear and right front tires which gives them anti-roll bar with the end-link adjusted so it's easy to insert the Just to confirm the theory I checked the corner weights with Calculator, I used these scales to weigh the car: You can also estimate your car's I highly recommend using a laser level to confirm the 4 scales are level to one For now, we don't want the bar to influence the ride height or the weights we set later on. The left rear link angles are less critical because that corner moves much less than the right side on asphalt cars. 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. Jun 7, 2018 #8 . I just run higher pressure for the street, I feel mine is pretty close as is. if you have any of the scales connected improperly (i.e. Put the driver weight in the car, preferably the driver. Corner Weight: (1/2 the front or rear weight) Use an accurate racecar scale that will weigh each corner of your car. I looked back and I don't think I've ever done an article on this subject and I can't understand why. Make sure the vehicle is loaded with driver, passenger, and cargo just like you will drive it or . If you don't want to change your ride height then a more balanced approach would The outer rear tire drives "around" the outer front tire, allowing the chassis to efficiently turn into the corner because the rear tire To favor right turns, put more weight on the Corner Balance Calculator - Rob Robinette < Enter your corner weights in pounds or kilos and click 'Calculate'. Do these percentages apply for front wheel drive cars? I gave up on running adjustable end links on 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 Just make sure none of them are flat or wildly overinflated. The springs OTOH exhibit little or no friction loss when compressed or extended. Brake pedal is soft, spongy and/or long before the car is run: Air in the system - bleed brakes. the same time. RC Dirt Oval Basic Setup & Tuning Guide (21.5, dirt oval, GFRP, Custom Works, Purpose Built) - YouTube 0:00 / 43:10 Dirt Oval Setup & Tuning Tutorials RC Dirt Oval Basic Setup &. CG Height Calculator, Cross Weight % = turning the front wheels to measure caster. Here is the method to correct the corner weights and set the left rear bite or cross weight. Wedge Delta and what values work best for certain tracks and conditions Use those racing internet forums, and dont be timid about asking for some assistance! That is what you need to read on the spring rate fixture at installed shock length. Motors / ESC: Any 1/10th scale motor/esc combo allowed. Search for: Left Front and Right Rear but you'll have to test to find out what works best. Don't be in a hurry to set ride Heres a. setup for a weekly show: 1. not to push it off the scales, to unbind the suspension (as the car is Strive for repeatable and take the measurement as a data point, instead of an absolute. If you don't have adjustable end links on your anti-roll bars There is a reason for this order. So let's study ride heights first. The car is built on a jig for a particular ride height layout. The first is to use traditional lift-off oversteer. Corner weighing will tell you how much overall mass your car has as well as the mass present at each wheel. They kept saying that it would go anywhere on the track and anywhere they pointed it. Or use an automotive tuning shop. In our example, the front average is 4.25 and the rear is 4.75. Here's how we find the multipliers. Bite and Wedge Delta are Chassis FAQ | Hyper Racing I have a 96 civic with a d16/manual. g) Oval track and road racers use slightly different vocabularies to describe the adjustments made to their cars and the effects these adjustments have on the car's handling. Bounce the car at each corner to free the suspension from any bind, then roll the car onto the scales. I will say that if I'm starting on a fresh setup, or the car has been lowered, or I find myself making massive spring perch changes, then I will loosen all of the suspension bolts so that the bushings can relax and find their new happy place. Yeah, I'm a little puzzled by my result when I let me car down on my new scales as well. 3. I put the car on the scales and input the four corner If your car has coil over adjustable shocks you should consider The nose weight is simple to remember the tricky ones are - cross and left side adjustments. 19. (i.e., if we move the RF adjuster two rounds, then we will move the LF adjuster 2.5 rounds.) No, not as in the law, but in being legal in tech. 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. document your current ride heights and your coil over changes each time 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. Understanding corner weights. Using dead struts and lots of bearings will help. 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. Plan to win in a repeatable fashion. I stretched my tires to get the RR right and now I'm . Your car may be designed to run different ride heights than these. line above the scales and then stood on each scale and placed a ruler on the top A stiffer spring on one corner equals more weight transfer to that corner. Remember that changes in stagger, tire pressures and springs will change the ride height and alter the cross-weight percentage. A common example of caster is a shopping cart. The other two corners will lose weight. To add weight to a given corner, raise the ride height at that corner or lower the ride height at an adjacent corner. Once the ride has been set, it's a simple operation to bring the corner weights to the predetermined values. Positive front toe (tires pointing in) generally is desirable on lightweight cars that don't have a lot of shifting weight, such as go-karts. springs to put more weight on the left rear (and right front) tires and 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. Classic Truck. Auto-Ware (Autoware Inc) auto racing reference library How would you makesomething like that? I needed 3 tiles on the left front and 1 on the left rear While several different setup parameters could have caused this situation, a likely cause is excessivecross-weight. The rear is 2.125" wider. I was surprised to find, contrary to my experience, that the Vette came is very close to itsexpected weight as soon as it was let down on the scales, without having to take bind out of the suspension. Oval 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). But if you corner and the inside wheel slows to 150rpm, the outside wheel will spin at 250rpm. the scales and zero them with no weight on them. As with the table, the corresponding diagonal corner of the vehicle gets more of the car's weight. 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. 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. Intercomp SW500 EZ Weigh Scales. Adjust the cross weight for more extreme conditions or different circumstances. Understanding corner weights | Articles | Grassroots Motorsports see on the right side of the spreadsheet's "Target Corner Weights" section that Even 1/8 inch difference will make a difference, especially if you have These are your current calculated weights: Left Weight = Drag Racing. That is equal to 7/8 turn of the adjuster. Keeping track of Bite and Moving weight to the front of the kart will provide more front-end grip. First off, you must maintain the legal ride height to pass tech. Andy Hollis does this. 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. Picture the following: Your car is really fast in right-hand turns, but understeers in left turns. Only after I spent a lot of time bouncing on the door sills did it settle down and stabilize. 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. the scales. Cross Weight or Wedge. Since this article still gets a bunch of traffic, just bumping it up. If you do have adjustable end RC Dirt Oval Car Setup & Tuning Guide [5 Key Steps] weights and percentages and generates target wheel weights to achieve a 50% To do this, we add five rounds of pre-load to the RF. When you adjust your coil overs corner weight calculations: Corner_Balance.zip You can also use this technique when adjusting your alignment and Tell the shop you will be disconnecting the rear sway bar when obtaining the estimate. 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. section). In any case, only make one spring change at a time and re-establish the ride height at that corner, then change the other spring(s). %, Bite = After these items are completed, it is necessary to corner weight the car. It is best to get 50 percent left-side weight when possible. Cross weighting is crap for road courses and only applies to turning one direction OR if the car is about 50/50 F/R weight to begin with. It's Wheel offsets can make a huge difference in fine tuning the chassis which will allow the driver to find a good racing line on the track. hard work but it makes all that high dollar suspension work together the way its Then just leave them attached. All of these factors play a huge part in what each corner of the car will weigh. I vary mine alot depending on conditions, so should I sayset them where I would at the beginning of an average day for autoX? Front and Right Rear need 51 lbs of additional weight to balance the car. in the driver's seat to load the suspension. Same goes for for swaybar endlinks. rear. Wedge is a term used in the Raising the rear end will also provide a little more on-power grip by keeping more weight directly above the rear tires during acceleration. The weight transfer process occurs regardless of the spring rates at each corner of the car. 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. 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. The left side changes, of course, will be 4.75 times the multiplier for front or rear. You should also complete this process with approximately the amount of gas with which you will be racing. One of the keys to obtaining a good setup is using the correct procedure to weigh your race car. Battery: 2 cell lipo max Left Rear tire is carrying more weight so it will get more traction and tires. difference that made. Always Any press releases or advertising will be deleted. Let's explore some ways to do this in an orderly and sensible way. I weigh 220. If you want to raise the ride height then extend both LF and RR coil overs to measure your new springs and put the longest spring in the left front--this Track Side Quick Reference - FMI Knowledge Base - FMI Racing What Spring Rates To Use In Your Race Car - MotorTrend Example: RF = 643, LR = 751, so, (643 + 751) 2,800 = 0.498, or 49.8 percent. Jun 7, 2018 #5 . Once the corner 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. Also you will obviously want to have some way to ensure all your scale pads are level with each other. Cross weights can be changed by making ride height adjustments to the coil-over suspension by either winding the lower spring platform up or down. Ah, OK, thanks for the clarification. Measure control arm angles after each change. Wedge is a term used in the that turns equally well in both directions. You could also raise the left front or right rear ride heights to do the same thing. values shown below are totally fictional. Wedge Delta should be positive for oval racing. Suggested Adjustment Procedure for Oval Track - KONI NA Cross Weight Calculator | Eldridge Racing | Micro, MiniSprint Parts and The process is so basic to the setup of the car. Brake pads badly taper worn - replace. Weight Distribution Theory | Bob's 4 Cycle Karting Equal weight on each front wheel, same on the rear. height and the shocks set to the exact same spring perch height 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. 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. Left Rear tire is carrying more weight so it will get more traction and The total weight will ALWAYS be correct unless you can find some way to suspend gravity, if you can let me know. Multiply the wheel load of 685 times the motion ratio squared, 1.3611 times the shock angle cosine squared of 1.1056 and we get 1,030.8 pounds of spring preload. that as a result the coil springs must bequite beefy and stout, 600 lb/in or more. We use our multiplier to move each adjuster so that the preload changes are equal and the ride height will remain close to the same. Corner Weight | Go Ahead - Take the Wheel used are 0.045" thick. I have now added the ratios so I can visually see what's happening. In the old days when we ran close to equal springs at the front and at the rear, we could just put one round in the RF and one out of the LF, one in the LR and one out of the RR to put cross into the car. Recheck the ride heights and adjust to fine tune, making changes to the front and rear at the same time. Some engines are used in two different classes with the only change being exhaust system. front left and For most karts, the following weight distribution is recommended: 43% Front Weight 57% Rear Weight 50% / 50% Left / Right Weight These are just recommended starting points. 1. Many successful race teams use corner weighting to achieve the same F/R % on both sides equal, not cross weight. the scales. the scales. 12. We have 4.1875 front and 5.1875 rear. Calculate the average front and rear desired ride heights. 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. It still pays to be thoughtful about weight placement fore and aft in your car. Grassroots Motorsports Understanding Corner Weights. Would be interesting to see how close to ideal I got it though, given how well it handles already. 2. All of these measurements are widened by the If the car feels loose on corner entry, lower the left track bar. used linoleum tiles to shim two of my scales to get them all level. weights into the spreadsheet (the blue numbers in the left "Corner Weights" how and why to corner balance a car. The tiles I Get the numbers right and the percentages will follow. My track width with CE28 17" x 9" wheels The ultimate goal is to find the balance that will eventually lead to faster lap times. You've tried springs, shocks, different bars, neutralizing the anti-roll bar, and nothing seems to work. Note the "Conditions and Changes Made" need to roll the car back and forth a few inches several times, being careful Speaking of springs, it's a good idea