That is why a stiffer right rear spring makes the car looser. 13. Motors / ESC: Any 1/10th scale motor/esc combo allowed. Adjustable end links are more 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. Also you will obviously want to have some way to ensure all your scale pads are level with each other. (TVW LSP) - LF = 769D. 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. pounds of preload to the scale weights. coil over 5 turns. Rear weight percentage for road racing and autocrossing is less definite. Disconnect the sway bar. Corner Weighting I see disconnecting the sway bar, and how to do it, but disconnect the shocks? I lowered the left rear spring perch 1 1/4 turn and put it on springs to put more weight on the left rear (and right front) tires and for the front and rear sway bars and installed them with my girl friend sitting the driver seat and reconnect them so there's no preload on them. No, not as in the law, but in being legal in tech. the front ramps then jack up the rear and lower it onto the rear scales. However, you can choose to use them. extra weight is on the left rear and right front tires which gives them Wedge Delta and what values work best for certain tracks and conditions Or am I missing something? Similarly, dirt oval cars often represent crossweight as "bite", or weight on the left-rear tire relative to the right-rear tire. For road racing and autocrossing, the ideal left weight percentage is 50 percent. decided to try 5 turns total of spring perch movement to balance the car. calipers. Interested in hearing peoples' opinions and (preferably) experiences. An analogy which is commonly used is to imagine that the car is a four-legged table. The effect of shock rod seal frictionat the wheel will be reduced by the crank leverage ratio. the same time. I started out with the KW spring perches set exactly the same Determine your ride heights. In our example, move the LR and RR corners down by 0.4375-inch. I use 2x6 wood planks as ramps to drive the car onto need to roll the car back and forth a few inches several times, being careful 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. 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. To add weight to a given corner, raise the ride height at that corner or lower the ride height at an adjacent corner. Unless you have some kind of stupid hyper-critically damped NASCAR type dampers this isn't really necessary. Just follow the steps and you can set the pre-load in the fixture to where it will be very close in the car. 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. That seem like a lot. ride heights after every change. 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. It has to, it's just the laws of physics. I'm not saying you get what you pay for with race scales but there is a reason I went with longacre. You're better off not corner balancing the car than doing it on an unlevel rear should be the same. 4m.net - The Most Opinionated Racing Message Board In The Universe. Once you have returned the wheel corresponding to the spring change back to its measurement, the other wheel measurements will be OK. 3. 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. Corner-Weight Distribution Bickel points out that corner-weight distribution refers to the amount of weight carried by diagonally opposed pairs of wheels. My track width with CE28 17" x 9" wheels It's just turning left 2 times per lap. I used a laser level to project a horizontal Splash = 2-3 gallons, 1/2 can = 5-6 gallons, 1 can = 11-12 gallons, 1 1/2 cans = 17-18 gallons, 2 cans = full tank. It also helps when shaking the car to take the bind out of the linkages. and Left Rear. height and corner balance new springs. hard work but it makes all that high dollar suspension work together the way its I borrowed some scales to weigh my Terceltomorrow. All of these factors play a huge part in what each corner of the car will weigh. To properly corner weight the car, it is necessary to add weight to the drivers seat which is approximately equal to the weight of the driver (or have the driver sit in the car). Any press releases or advertising will be deleted. . knew I needed to put the car on the scales. Some racers like to take matters into their own hands-and that's OK. The driver is optional based on No. Typical racing scales will calculate this for you automatically, but you can rig up something that will work using a single scale and 3 equal sized spacers to get a good estimate. need to roll the car back and forth a few inches several times, being careful 2) Stagger: Stagger is how much bigger the right side tires are compared to the left side tires. Since I went to 800 front and 700lb rear springs over the winter I Then move components like the battery or fuel cell. On Dirt cars, adding Rebound to the Right Rear will make the car more stable when it slides into the cushion. rod movement from the wheel to the coilovermovement. to get them exactly level. One of the most important aspects of car setup is the static weight distribution and the cross-weight percentage. Measure control arm angles after each change. 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 &. Some engines are used in two different classes with the only change being exhaust system. 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. If a setup sheet read as "30 pounds of bite", there would be 30 pounds more weight on the left-rear than the right-rear. cross weight. I made a 4-scale system for my off-road cars. Plan to win in a repeatable fashion. Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. Before putting your car on the scales you need to power up 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. Brake pads badly taper worn - replace. 10. I overshot by a little so I raised the left rear spring perch by 1/2 At the front, we will move the LF and RF adjusters up by 0.0625-inch. I guess I should work on losing weight personally (i am 220~). Even 1/8 inch difference will make a difference, especially if you have You can estimate your car's center of gravity You can also use this technique when adjusting your alignment and You can use rubber tires on very specific tracks and seasons. intentionally favor a turn direction. Once you have established an ideal moment center design and the correct cambers through testing, you need to maintain those throughout your season. Since the front and rear shocks are of different lengths you This is my 2001 S2000 with 1/2 tank gas, 216 To do this you need to enter a corner at the car's limit of adhesion and then peel off the throttle aggressively. The spreadsheet's second page has a good article that goes into more detail of positive Bite and positive Wedge Delta. I We have 4.1875 front and 5.1875 rear. Youre always going to have some friction, especially depending on the type of suspension used. 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. Wheel offsets are very important. 1) Tweak: Tweak is the amount of weight on the LR as opposed to the RR. For this exercise, we will just be changing the pre-load on the springs to redistribute the loads, or weights on the four corners. [ 1] In circle track racing, the use of the term "crossweight" gives us an indication of the weight distribution on the four tires. . more important corner balancing becomes. A. May 2017 -Dirt late model pinning RF & heavy axle tube. Wheelbase: 9.5" min, 11.5" max Maximum width: 10.250" Minimum weight: 57.0 oz All cars must have 4-wheel independent suspension, single speed transmissions only. dry)! racers discovered they could insert an actual wedge into the left rear Now that we understand the value in maintaining ride heights, just what heights do we want? In April 2013 I corner balanced the S for the first time in All rights reserved. This spreadsheet will also give you an estimated center of gravity height if The situation isfrustrating. You should also complete this process with approximately the amount of gas with which you will be racing. 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. adjustment so I have a history of each adjustment. There are several ways race teams adjust corner weight. Adjust the front up by 0.0625-inch and the rear down by 0.4375-inch. That is because all of the points move together. Left Front and Right Rear but you'll have to test to find out what works best. 1. Here is what you do. I even thought my excel spreadsheet calculated it's recommended corner weights to achieve 50% cross weight. Moving weight to the front of the kart will provide more front-end grip. For ovals we want a You should read the spring preload amount. Lowering the cross weight does the opposite of raising the cross weight. stiff springs on your coil overs. Wedge Delta can also be thought of 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. The angles are another way to set the suspension for the desired ride height and cross-weight percentage. You can see the article here: Make small changes at the track, and make only one change at a time. April 2017 -Bracketing settings, 4WD high speed pavement vehicle. Only after I spent a lot of time bouncing on the door sills did it settle down and stabilize. Jacking weight will not alter the left side or the rear percentages. Are they adjustable? 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 that level of caring, I wouldn't think too much about it. to get the desired corner weights your ride height will change. 45. Let's explore some ways to do this in an orderly and sensible way. It is best to get 50 percent left-side weight when possible. scales are connected properly--you can really screw up your suspension settings Andy Hollis does this. that as a result the coil springs must bequite beefy and stout, 600 lb/in or more. If you get the car neutral in left turns, it oversteers in right turns. All 4 scales must be within 1/8 of an inch. Left Rear tire is carrying more weight so it will get more traction and They are never level. rear. 11. I usually mark an even inch and write that inch number on the tape. as Left Rear Bite + Right Front Bite. This measurement can be manipulated by changing spring rates, coilover . Choose a level spot in your setup area. Please post on the appropriate 4m forum. You can see that the leverage ratio in the crank link reduces coilover(and thus shock) travel, and Always try to start with the track bars first. Small angles can throw off your readings significantly. You've mentioned "dead struts" a couple of times - what do you mean by that? If the driver lifts early but still has a fairly good amount of roll speed into the corner, there probably isn't much brake being used. Left Front and Right Rear but you'll have to test to find out what works best. Bite = Left Rear - Right Rear and a positive value means the If the person reduces the force with which he's pressing against the ceiling, the weight read by the scales will decrease. < Enter your corner weights in pounds or kilos and click 'Calculate'. To favor right turns, put more weight on the 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. (I suppose cooking oil, motor oil, KY, or Astro-Glide would also work). Brake pedal is soft, spongy and/or long before the car is run: Air in the system - bleed brakes. which is simply the difference between the two diagonal tire weights. The Track (FATT) event and it handled superbly. How big is the track? Bite tells us how much we We delve deeper into race suspension tuning basics here. I recommend adding an eighth or slightly more to the lowest corner just to make sure you pass tech. R. racing junky Member. Keeping track of Bite and Bottom line, you can strive for perfection, but ultimately youll just make yourself crazy. Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. Thanks; what you say makes sense, of course, but repeatability is always going to difficult unless you can get rid of most of the bind, right? measure (literally). Many electronic scales will perform the calculations for you. The rear is 2.125" wider. Wedge is a term used in the The tiles & salt seemed to help because the weight never lowered onto the scales the tires will need to spread out to unbind the . 9. - Use blocks the same height as your scale pads to move the car off the scales to make adjustments. Wedge Delta can also be thought of My car is a 1987 Honda CRX, set up according toITC class rules. 11. 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. retract the right rear tire which puts more weight on the Left Rear and I needed 3 tiles on the left front and 1 on the left rear Shock binding is not caused by the fluid (which is only a factor withfluid movement through orifices/valves), but from the seals, which possess both static and dynamic friction. weights into the spreadsheet (the blue numbers in the left "Corner Weights" Shock Position To find LR weight: center of gravity (CG) height by using this page: The roll center is an imaginary point around which the rear of the race car rolls. the same time. the sway bars because they fail so often and the bars only added a couple of You will need to weight your vehicle on each tire to use this tool. When that time arrives, you walk across the racing surface, into the dirt oval's imperfectly defined center, and meet your instructor. springs settled over the first 3 months. 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. In other words, to make this method work, wouldn't you really have to drive the car around, preferably going over a few pretty serious bumps, before driving onto the ramps? Go in hard, let off and let the drag brake pivot the car, and get right back on the throttle. Cross-weight percentage compares the diagonal weight totals to the car's total weight. I use this technique and it Adjusting the sway bar is time consuming and questionable unless it is really stiff. Yeah, I'm a little puzzled by my result when I let me car down on my new scales as well. They're made by Proform, and are quite a bit less expensive than the ones made by Intercomp, but they got good reviews. (i.e., if we move the RF adjuster two rounds, then we will move the LF adjuster 2.5 rounds.) It's They kept saying that it would go anywhere on the track and anywhere they pointed it. That math gives us a percentage number to . In order to perform the set up routine the car needs to be completely ready to race. I can see binding throwing off each corners weight but the sum should be the same. balancing see my corner balance how-to and Positive Caster is created when the caster line lands forward of the contact patch. Here is a screenshot with some random-ass corner weights. It's better to make many small changes than to try Intercomp SW500 EZ Weigh Scales. Taking the time and making the effort always pay dividends. Then the car will move more easily from one setting to another. Do not adjust any other wheel's spacing. Many successful race teams use corner weighting to achieve the same F/R % on both sides equal, not cross weight. Do these percentages apply for front wheel drive cars? It varies with weight removal, added. I still rolled the car back and forth a There is work involved in going fast for the full race and racing other racers clean. (CG) height by using this online calculator: CG Height Corner_Balance.zip, Excel Corner Balance Spreadsheet Screen Capture. This will pitch the vehicle's. Recheck the ride heights and adjust to fine tune, making changes to the front and rear at the same time.