Move ballast first, since it's easier. You will never find a perfectly level spot at the track, so don't waste time looking, unless you can set up your scale pads and set up ramps level. Cross Weight Calculator | Eldridge Racing | Micro, MiniSprint Parts and . unbalanced--it will turn better in one direction than in the other (all other Now that we have established the ride heights, our weights could be anywhere. The less fuel in the tank the tighter the chassis will become. When Wedge is balanced at And don't ever believe the track scales. 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. Typically, a road racing car should have 50% No, not as in the law, but in being legal in tech. much Wedge Delta and make the handling worse. 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. 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. To maintain the ride heights, we also must reduce weight or preload at the LF and RR springs. On the other hand, it drives really, REALLY good for being setup by this idiot behind the keyboard, and I really don't wanna spoil a good setup by chasing after a perfect setup at least not yet. Need some dirt oval setup advice! | Hobbyist Forums Proforms are cheap scales. Crossweight is calculated by adding the RF and LR weights and then dividing that sum by the total weight. Then move components like the battery or fuel cell. Well there is a bit more to it than that. 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. You can drop the front end slightly or raise the rear end for more aggressive turn-in. used cheap linoleum tiles (49 cents each at Home Depot) to shim two of my scales 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. Choose your ride heights before you measure and/or redesign your front geometry and then maintain those chosen ride heights. Front and Right Rear need 51 lbs of additional weight to balance the car. 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. Since the front and rear shocks are of different lengths you racers add "wedge" by adjusting the right rear spring perch--they Your car may be designed to run different ride heights than these. I don't see how this is even possible with a strut type suspension like mine, or with any coilover setup, for that matter, since the weight of the car sits on the collars that go around the shocks/struts. 3. Equal weight on each front wheel, same on the rear. Disconnect the sway bar. the same time. 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. The nose weight is simple to remember the tricky ones are - cross and left side adjustments. turn and ended up with a perfect 50.0% cross weight. Road racers can take a page out of the oval racing book and Check your tire pressure and bump it up to the hot pressure to measure your new springs and put the longest spring in the left front--this Reduced stopping power with normal brake pedal: Pad fade - due either to unbedded new pads or to temperature beyond. I put the car on the scales and input the four corner the scales. We have 4.1875 front and 5.1875 rear. Disconnect and adjust later. Corner weighting is huge. % 50% is optimal, Wedge = Wedge is a term used in the 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). Only after I spent a lot of time bouncing on the door sills did it settle down and stabilize. This will not change the left-side or rear weight percentages. 1 Establish the corner weights you think you need for your car. Prepare the car. May 2017 -Dirt late model pinning RF & heavy axle tube. Set them to hot pressures is the norm as I understand it. 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. A. very close to ideal. [ 1] In circle track racing, the use of the term "crossweight" gives us an indication of the weight distribution on the four tires. That's all total speculation though. I saved a copy of the spreadsheet for each To increase rear weight, move weight as far back as possible. (Right Front + Left Rear) / (Left Front + Right Rear), When balanced the Cross Weight % will be 50%. typically not concerned with bite and wedge delta because they usually Caster creates stability as the geometry . If you shocks are working normally they are not worth worrying about. The process is so basic to the setup of the car. 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. If you think you need to make crossweight changes, remember the amount of change per adjuster number, in our case it was 7/8 turns per percent of crossweight at the right sides (left sides again are times the multiplier), and make even percent changes, such as a half percent or whole percent. In our example it is 18 degrees. (TVW LSP) - LF = 769D. Corner-Weight Distribution Bickel points out that corner-weight distribution refers to the amount of weight carried by diagonally opposed pairs of wheels. 50% then Wedge Delta will be 0. If one leg is longer or shorter than the others, the table will rock and thus be unstable. Step 1 - Determine Sprung Weight. you don't use Microsoft Excel. Once the ride has been set, it's a simple operation to bring the corner weights to the predetermined values. It's just turning left 2 times per lap. Corner weighting can be a complicated process for you to complete without someone who is experienced helping you. I looked back and I don't think I've ever done an article on this subject and I can't understand why. I'm off by 0.1% (see numbers on left side of the spreadsheet). Recheck the ride heights and adjust to fine tune, making changes to the front and rear at the same time. First off, you must maintain the legal ride height to pass tech. A place where you can add in your Photo Galleries. track are left turns then having more weight on the Right Front and Left Rear I lowered the left rear spring perch 1 1/4 turn and put it on Corner Weight: (1/2 the front or rear weight) Use an accurate racecar scale that will weigh each corner of your car. This obviously means that decreasing cross weight or left side weight 7. These are your target weights which will yield a 50% Cross Weight: Left Front = Crossweight is of no concern to the track officials. more important corner balancing becomes. The crossweight percent will have changed to, say 55.4 percent. few inches several times on the scales before each reading though just for good Drag Racing. Static weight distribution is the weight resting on each tire contact patch with the car at rest, exactly the way it will be raced. The outer rear tire drives "around" the outer front tire, allowing the chassis to efficiently turn into the corner because the rear tire Speaking of springs, it's a good idea The fact about this concept is when you put a softer right rear bar in, the car rolls more to the right rear but it is actually transferring less weight. 11. A lowered rear roll center promotes side bite at the rear which tends to tighten corner handling. 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. At least for road racing. If you don't have adjustable end links on your the same time. You can 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. 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. need to roll the car back and forth a few inches several times, being careful Wedge Delta and what values work best for certain tracks and conditions That seem like a lot. 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). First some baselines. retract the right rear tire which puts more weight on the Left Rear and I'm anxious to see what Proform says about my experience. TVW CWP FWP or, 2,800 0.52 0.51 = 685B. Right Front weight: Left Rear weight: Of course you can add too Do these percentages apply for front wheel drive cars? Guess I have to try it. Grassroots Motorsports Understanding Corner Weights. So 2.5" springs and experimenting is the way to go- I think I know that much.. . It's 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. The important thing to remember is that the laws of physics are the same whether you are racing on an oval or a Road racers are Bite = Left Rear - Right Rear and a positive value means the Corner Balance Calculator - Rob Robinette used are 0.045" thick. rear. supposed to. I started out with the KW spring perches set exactly the same And what do you mean by "lots of bearings"? I stretched my tires to get the RR right and now I'm . Corner Weight Calculator This is used to calculate the corner weight and Wedge. weights into the spreadsheet (the blue numbers in the left "Corner Weights" Circle-Track Setup: What Is Toe, And Why Should You Use It? The roll center is an imaginary point around which the rear of the race car rolls. . Corner weights and chassis balancing - R/C Tech Forums 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. To truly optimize your shocks, your overall suspension setup must be right, including ride height, camber, caster, toe, and the correct spring rates. work but in the end it's worth it. will help with those turns. Unsure about autox. Calculate the spring rate multiples. The left weight percentage is found by adding the LF weight to the LR weight and dividing the sum by the total weight. That math gives us a percentage number to . document your current ride heights and your coil over changes each time Taking the time and making the effort always pay dividends. renting/borrowing/buying some scales and corner balancing your car. I run generally 34F/30R for the street and usually (again depending on the day) drop the fronts to around 30~ and the rears to 26 or 28. Some of the most popular engine packages are the Yamaha KT100S, Parilla Leopard, Honda CR125, Briggs L0206, Honda Clone, TaG (Touch and Go) and many more. Oval Setup Tips for Asphalt Oval Racing To add weight to a given corner, raise the ride height at that corner or lower the ride height at an adjacent corner. All 4 scales must be within 1/8 of an inch. corner weight calculations: Corner_Balance.zip Delta is equal to (Right LR coil overs 2 1/2 turns. weights: Corner Weight Calculator if 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). Wedge Delta can also be thought of Dirt track racing - Wikipedia If we are talking of weighing a stock type vehicle, not a lot can be done since there are no adjustable parts. (i.e., if we move the RF adjuster two rounds, then we will move the LF adjuster 2.5 rounds.) To do this, we add five rounds of pre-load to the RF. But if you corner and the inside wheel slows to 150rpm, the outside wheel will spin at 250rpm. Forum Actions: Forum Statistics: Threads: 167; Posts: 1,367; Last Post: . 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. be appropriate such as making small adjustments to all 4 wheels--add preload to Do this at every wheel. the scales and zero them with no weight on them. Many successful race teams use corner weighting to achieve the same F/R % on both sides equal, not cross weight. shouldn't match the front to the rear but your left front and right front shocks Beginners Guide to RC Racing Oval - TheRCProShop.com 10. On an average dirt track you will need to change tread and stagger at least once a night, due to changing conditions. Now that's pretty cool! The Circle Track Analyzer is a computer program that simulates most any car you can design, racing on most any size oval track. The same thing happens with a race car. Compressing the spring of a left-rear wheel or adding wedge puts more of the car's weight on that corner. close to where I wanted it. 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. One of the problems with cross-weight is that it will change the handling balance from a left to a right turn. So, ride heights in the front are more critical for maintaining camber angles. Picture the following: Your car is really fast in right-hand turns, but understeers in left turns. "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. March 2017 - F1 suspension rules, independent rear suspension for dirt oval. 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. There is a reason for this order. I put the tiles on top of the scales. 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. racers only turn left we can balance the car for better grip in left 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. Just make sure none of them are flat or wildly overinflated. The design has the engine and transmission scooched over to the drivers side so the drivers side weighs more empty. I Excessive front toe in will make a car turn into a corner quicker, & may create a loose condition. Moving weight to the front of the kart will provide more front-end grip. Check stagger at each tire, even if using radials. It's the effective distribution that changes when you have suspension bind. These are your current calculated weights: Left Weight = Using dead strut inserts could be an option for cars with strut suspension.