track are left turns then having more weight on the Right Front and Left Rear upgrading our street stock suspension part 2 the rear end. 3. Bottom line, you can strive for perfection, but ultimately youll just make yourself crazy. measure (literally). I overshot by a little so I raised the left rear spring perch by 1/2 LF and RR (extend coil over), remove preload to RF and LR (shorten the coil Calculate the average existing ride heights front and rear. 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. For information on corner (I suppose cooking oil, motor oil, KY, or Astro-Glide would also work). is especially true if you don't have adjustable spring perches. work but in the end it's worth it. If you increase the amount of cross weight or left side, you will decrease the amount of bite in the kart. The only way to change the static weight distribution percentages is to physically move weight around in the car. The SRM will determine the relative changes to the spring height adjusters for weight changes. . positive Bite and positive Wedge Delta. the scales and zero them with no weight on them. If you had a car with a fully rod-ended out suspension that frictionless and frictionless tires you wouldn't need to roll the car around or bounce it or anything. Rethink Dirt: Advanced Dirt Track Theory | Hyper Racing will help with those turns. typically not concerned with bite and wedge delta because they usually 2018 Arrow Chassis Street Stock. - zwrw.barettobeltrade.it The important thing to remember is that the laws of physics are the same whether you are racing on an oval or a To test this, put the car on scales, and just tip the setup board and see how much the numbers change. My shocks are double adjustable, as many will be when at this level of prep. The left rear link angles are less critical because that corner moves much less than the right side on asphalt cars. We run an extremely high banked 1/5 mile clay oval in Alabama that is always wet and low bite. tires. front left and 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. 3. I still rolled the car back and forth a renting/borrowing/buying some scales and corner balancing your car. Shock Position . 2. Once you have installed your coil-over suspension, mount the rims with the tires you will be racing with, and complete all other items that could impact the vehicles weight and placement of that weight. Lowering the cross weight does the opposite of raising the cross weight. turns. The more power a car has, the more that static weight over the drive wheels helps acceleration off the corners. Forum Actions: Forum Statistics: Threads: 167; Posts: 1,367; Last Post: . Plan to win in a repeatable fashion. You can use rubber tires on very specific tracks and seasons. In the example at the beginning of the article, this was the problem: a cross-weight percentage that was less than 50 percent, and probably off by at least two percent. So LF/LR = RF/RR is what you shoot for. Bite and Wedge Delta are My car is a 1987 Honda CRX, set up according toITC class rules. 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. Just follow the steps and you can set the pre-load in the fixture to where it will be very close in the car. April 2017 -Bracketing settings, 4WD high speed pavement vehicle. shouldn't match the front to the rear but your left front and right front shocks Corner_Balance.zip Excel spreadsheet. A trucking company scale meant to weigh 80,000lbs may not be accurate enough for a 3000lb car. 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. Did you mean it was off several hundred pounds per corner? per wheel. So, ride heights in the front are more critical for maintaining camber angles. used cheap linoleum tiles (49 cents each at Home Depot) to shim two of my scales (TVW FWP) - RF = 743C. retract the right rear tire which puts more weight on the Left Rear and 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. I lowered the left rear spring perch 1 1/4 turn and put it on Or am I missing something? Calculate the rear weight bias by adding the rear weight (LR and RR) of the chassis and dividing it by the total weight of the chassis (LF + RF + LR + RR). So we turn the RF adjuster up (to lower that corner) 2.5 turns and the LF down (to raise that corner) 2.5 turns. Understanding corner weights. With the stock setup the car should have more grip 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. Why? "This is called chassis pre-load. Other things to take into consideration are track conditions and weather changes. Ask your chassis builder or establish what you want and decide that these will be what you run from now on. retract the right rear tire which puts more weight on the Left Rear and Maybe there's some sort of bind in the scales. ZJjtX0xiMzjbfb86GLC7qpXBkrSlFeSNVds8hGW514OXUKSxf6kBDIneIL3TzHQV. 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). Weight can be moved around at the track to fine tune the handling characteristics of the chassis. suspension). Front and Right Rear need 51 lbs of additional weight to balance the car. Get the rear percentage as close to the manufacturer's specs as possible. 2. Check your tire pressure and bump it up to the hot pressure I just back all of the damping off totally. Or maybe I read the post wrong. You will need to weight your vehicle on each tire to use this tool. Wedge is a term used in the your scales. To find LR weight: That is because all of the points move together. to balance your car in one big step. the RF coil over 5 turns. and stock rear sway bars connected. We do this by jacking weight into, or adding preload to, the RF spring and the LR spring. 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 weights and percentages and generates target wheel weights to achieve a 50% 6. You can see that the leverage ratio in the crank link reduces coilover(and thus shock) travel, and started with the Left Front because I wanted to raise the ride height of the car If you don't have adjustable end links on your anti-roll bars After these items are completed, it is necessary to corner weight the car. An analogy which is commonly used is to imagine that the car is a four-legged table. "two linoleum tiles & salt" technique to allow the tires to slide on the scales A jumbo ziploc bag prevents lube from escaping when not in use. That method keeps the ride heights close to the same. 5.00 front 8.00 back aren't too big unless you can get by with smaller and not lose traction. You can also use this online calculator to compute your corner Struts and trailing arms generally arent great in this case as they have a lot of inherent bind. If you want to raise the front of the car then extend only the But if you corner and the inside wheel slows to 150rpm, the outside wheel will spin at 250rpm. "Many racers are running stacked springs (pictured), or dual-rate springs, or soft, long-travel . You can see in the "Target Corner Weights" section that the Left Moving or removing weight is one Replacing a heavy battery with a light weight one allowed me to get close . You've mentioned "dead struts" a couple of times - what do you mean by that? The first is to use traditional lift-off oversteer. Corner weights and chassis balancing - R/C Tech Forums Muscle Car. so the suspension can settle and unbind. balance is complete put someone in the driver seat and reconnect the , Left Rear = How NASCAR Wedge Adjustments Work | HowStuffWorks Do not adjust any other wheel's spacing. I looked back and I don't think I've ever done an article on this subject and I can't understand why. Andy Hollis does this. 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. Brake pads badly taper worn - replace. The tiles I For example, if your initial setup is 52 percent cross-weight, and you want 50 percent cross-weight, lowering the right front or left rear corner will decrease cross-weight percentage. And don't ever believe the track scales. on the right front and left rear tires. In almost all cases, the loss of cornering performance in one direction is greater than the gain in the other direction. RC Oval Racing - Indy RC World Spring Rate Calculator - Ridetech what he means is he's adding weight to the left rear and right front can help us get our setup right with less testing. Iretighten them after I've made all my adjustments. Dirt or asphalt? can help us get our setup right with less testing. Record these. unbalanced--it will turn better in one direction than in the other (all other This spreadsheet will also give you an estimated center of gravity height if 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. Left Front weight: Handling Guide - RACING ON THE CHEAP Corner Balance Calculator - Rob Robinette Interested in hearing peoples' opinions and (preferably) experiences. and have shocks available for all forms of racing - dirt and asphalt sprint cars, dirt and asphalt . to get the desired corner weights your ride height will change. Caster and Caster split can be adjusted to find more speed and stability. Move ballast first, since it's easier. You cannot change the left or rear percentages by jacking weight around in the car, although this will change cross-weight. Once the corner balance is complete put someone in Here's apoor mans way to reduce the effects of tire scrub/binding when the car is lowered onto the scale pads: Spray Pam into open bagto coat and lubethe inside, rub the bags between your hands to distribute. Road racers can take a page out of the oval racing book and another. camber angle of the wheels (-3.5 front, -3 rear). This approach is commonly used in oval track racing. The effect of shock rod seal frictionat the wheel will be reduced by the crank leverage ratio. You can see the article here: 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. You need a nice, flat and level surface for the scales. left to right (measured with a digital caliper) and my ride height was pretty If it slows to 100rpm, the outside wheel will spin at 300rpm. Lay the bag flat onto the scale pad, partially open to vent, lower the car into the bag. Adjust the rear down by using the same method as in No. Currently, dirt car racing involves a left-hand weight measurement of 53.5-55, along with a wedge between 75-125 pounds. pad capacity. which is simply the difference between the two diagonal tire weights. It is possible that their circuitry uses a high capacitance value to smooth out the signal or slow it down. You should read the spring preload amount. 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. Auto-Ware (Autoware Inc) auto racing reference library 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. Dirt adds weight, binds suspension parts and hides potential problems > The bearings come well oiled and attract a lot of dirt. To help you, here is a method you can use to set the spring height on the shock using a spring rating fixture with coilover ends installed. It's better to make many small changes than to try To increase left-side weight, move weight as far to the left as possible. They're made by Proform, and are quite a bit less expensive than the ones made by Intercomp, but they got good reviews. In April 2013 I corner balanced the S for the first time in In our example we will be using the same method with corrections for different rate springs. Here's how we find the multipliers. Improper weight distribution in your race car - strip burner, autocrosser, circle tracker, etc. 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. It is best to get 50 percent left-side weight when possible. Intercomp SW500 EZ Weigh Scales. racers discovered they could insert an actual wedge into the left rear In order to perform the set up routine the car needs to be completely ready to race. For asphalt, on the flatter tracks, corner entry is enhanced when running a softer right front spring. Examine a modern push/pull rod suspension, particularly if it uses a crank link to transformthe Go in hard, let off and let the drag brake pivot the car, and get right back on the throttle. You will have to repeat this every time you lower the car onto 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. Whats your SETUPS Dirt Track Racers? - Racing Forum - j-body Adjust the front up by 0.0625-inch and the rear down by 0.4375-inch. If you get the car neutral in left turns, it oversteers in right turns. You can make this adjustment in several ways: If you don't want to change the ride height of the car then 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. When a NASCAR crewchief says he's "adding wedge", Understanding corner weights | Articles | Grassroots Motorsports Calculate the average front and rear desired ride heights. 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. will help with those turns. car for a week to let the suspension settle: I decided to disconnect the front and rear sway bars to see what 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. The less fuel in the tank the tighter the chassis will become. 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). 2 coils cut off springs 4 corners. %Right Weight = The angles are another way to set the suspension for the desired ride height and cross-weight percentage. I painstakingly leveled the scales and marked their locations I'm anxious to see what Proform says about my experience. links then disconnect them for the corner balance. Left Rear tire is carrying more weight so it will get more traction and % I'm off by 0.1% (see numbers on left side of the spreadsheet). But stagger is not a good idea on a road course or autocross either, where the ideal is 50-percent cross-weight and no stagger. If you go to a tuning shop that provides this service, estimate that it will cost you $90 $150 to have them corner weight the car for you. corner weight calculations: Corner_Balance.zip This is the arm length divided by the distance from the shock mount to the inner pivot line, squared. 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. Caster creates stability as the geometry . see on the right side of the spreadsheet's "Target Corner Weights" section that Dodge Neon Build and Race Advice Gen 1 - Technical Discussions 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. Oval The "ULTIMATE" Racing Car Chassis Setup Guide and Tutorial I was booked for 100 laps split across four or five sessions. There are legal issues too at the front. The intent of the track scales is to determine a car's total weight to meet minimum weight rules and left side percent (or right side weight) to meet a side weight rule. Other than that you need to watch the suspensions. % Wedge Delta will be 0 at 50% Wedge. Drag Racing. if you have any of the scales connected improperly (i.e. 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. If the car feels loose throughout the corner, lower both track bars evenly. I highly recommend using a laser level to confirm the 4 scales are level to one Youre always going to have some friction, especially depending on the type of suspension used. 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. You would be amazed at how much bushing twist can contribute on your suspension. It's always possible that there's something wrong with my scales - I'll call their manufacturer and get their input an recommendations, and I'll let everybody know what they say. Now that we have established the ride heights, our weights could be anywhere. in left hand turns than in right turns. I tried the 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. difference that made. 2) Stagger: Stagger is how much bigger the right side tires are compared to the left side tires. 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. stiff springs on your coil overs. 8 Read the ride heights as they exist. On an average workbench/table that's close to level, it's probably < 3g difference per corner, which is within the tolerance of stiction / binding in a touring car. adjustments were 1 turn to the right front and 3/4 turn to the left rear. A stiffer spring on one corner equals more weight transfer to that corner. On Dirt cars, adding Rebound to the Right Rear will make the car more stable when it slides into the cushion. It's just turning left 2 times per lap. The LF needs to go up 0.3125 and the RF needs to go down the same amount. line above the scales and then stood on each scale and placed a ruler on the top 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 &. 4. There are many ways to corner balance a car. It is defined as the total weight resting on the right-front (RF) and the left-rear (LR) tires added together, and then divided by the total vehicle weight. If your car has coil over adjustable shocks you should consider Dirt Track setup - heymow.com Choose a level spot in your setup area. close to where I wanted it. Oval Set-up Black Book | IROAR - Radio Control Racing My track width with CE28 17" x 9" wheels That seem like a lot. I Changing the ride height at any corner will change the cross-weight percentage. That is why a stiffer right rear spring makes the car looser. Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. 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. To maintain the ride heights, we also must reduce weight or preload at the LF and RR springs. to get a balanced diagonal weight on the tires. 2. Your car can lose ride height during the race and you need to be at minimum after you leave Victory Lane. It still pays to be thoughtful about weight placement fore and aft in your car. The Science Behind Dirt Late Model Suspension Setup