This spreadsheet will also give you an estimated center of gravity height if
Would be interesting to see how close to ideal I got it though, given how well it handles already. 11. racers discovered they could insert an actual wedge into the left rear
I always thought it was the other way, shock travel was increased in order to have more movement for better control over the suspension?
I would imagine that disconnecting the shocks is only applicable to setups where the shock and spring are separate, like a lot of solid axle cars, or Mk2 Supras in my experience. I was surprised how much these high rate
For our example, we need to go from 49.8 to 54 percent. over). Measuring from the center of the tires I got
works well. 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. Small angles can throw off your readings significantly. the scales and zero them with no weight on them. another. Beyond that, if your bushingsand other parts bind on the scales then they're also going to bind out on the road, so who cares? suspension). Oval
need to roll the car back and forth a few inches several times, being careful
So if you have 60% on the front , you should have 30% on each front wheel. Rethink Dirt: Advanced Dirt Track Theory | Hyper Racing You could also raise the left front or right rear ride heights to do the same thing. I've had my cars corner balanced a lot, but never really looked into the science of it. Changing the ride height at any corner will change the cross-weight percentage. Always try to start with the track bars first. 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? Choose a level spot in your setup area. can help us get our setup right with less testing. For our example, we use LF 4.00, RF 4.50, LR 4.50, RR 5.00. Now that we have established the ride heights, our weights could be anywhere. 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. To increase rear weight, move weight as far back as possible. Motor: 550 or 540 motors only. 2. , = change needed to get to target weight, Cross Weight =
bite, a negative value means the Right Rear is favored. 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. 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. Then the car will move more easily from one setting to another. If you decide to have a tuning shop complete the corner weighting and assuming you are not driving the car to the shop, disconnect the rear sway bar yourself to save the shop time and you money. There are legal issues too at the front. One of the keys to obtaining a good setup is using the correct procedure to weigh your race car. Dirt Late Models. Oval Set-up Black Book | IROAR - Radio Control Racing from a balanced Cross Weight. Other things to take into consideration are track conditions and weather changes. 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. Bite and Wedge Delta are
Rock or bounce the car helps. I was booked for 100 laps split across four or five sessions. Many successful race teams use corner weighting to achieve the same F/R % on both sides equal, not cross weight. Strive for repeatable and take the measurement as a data point, instead of an absolute. . Astrut with its innards removed? 4 Establish the exact weight change in percent that a given spring height change will make and record that number. Adjusting the corner weights is how we establish the crossweight percent, or what is often referred to as the amount of bite, left rear weight, or wedge. upgrading our street stock suspension part 2 the rear end. 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. I created a Microsoft Excel spreadsheet do the following
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. You can see in the "Target Corner Weights" section that the Left
And I cannot really move any weight around. you weigh and adjust. "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. 4. springs to put more weight on the left rear (and right front) tires and
important for cars with upgraded (stiffer) sway bars because they can exert a
Funny. Since oval
Full of fuel, everything done, full of oil, lead bolted down. I dropped my integra off at edge to have this done today. You need a nice, flat and level surface for the scales. Today, dirt late model racers are using cutting-edge tools to pinpoint where gains can be made based on hard data. All of these measurements are widened by the
as Left Rear Bite + Right Front Bite. 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. Handling Guide - RACING ON THE CHEAP They are never level. center of gravity (CG) height by using this page:
I use 2x6 wood planks as ramps to drive the car onto
And if you hold the inside wheel so it can't spin, the outside wheel will turn 400rpm. Once the corner balance is complete put someone in
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. So, we are not reinventing the wheel here, just refining the process. Many electronic scales will perform the calculations for you. 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. which is simply the difference between the two diagonal tire weights. With my KWV3 shocks I had to remove the wheel to adjust the
A trucking company scale meant to weigh 80,000lbs may not be accurate enough for a 3000lb car. Doing the multiplication to square that number, we get 1.1056. PDF kart chassis setup and tuning manual - Southwest Karters For our example we have LF 3.625, RF 4.75, LR 4.625, RR 5.75. How To Set Up RC Dirt Oval A Guide - Explained! If you have uneven mass on your wheels then your tyres will all have different levels of grip which can lead to an unpredictable car on circuit and make it corner faster in one direction than the other. These weights are in ready to race form (including driver on board). It's stuff closer to 60/40 or 40/60 where you need to stray from crossweighting. retract the right rear tire which puts more weight on the Left Rear and
You've tried springs, shocks, different bars, neutralizing the anti-roll bar, and nothing seems to work. Jun 7, 2018 #8 . Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. I just run higher pressure for the street, I feel mine is pretty close as is. Corner Balance - Rob Robinette Cross Weight Calculator | Eldridge Racing | Micro, MiniSprint Parts and . I tried the
Check static weight before working on cross-weight. Plan to win in a repeatable fashion. In April 2013 I corner balanced the S for the first time in
Guess I have to try it. them for the corner balance. On Dirt cars, adding Rebound to the Right Rear will make the car more stable when it slides into the cushion. I can see binding throwing off each corners weight but the sum should be the same. 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. see on the right side of the spreadsheet's "Target Corner Weights" section that
left to right (measured with a digital caliper) and my ride height was pretty
If your car has coil over adjustable shocks you should consider
Your car can lose ride height during the race and you need to be at minimum after you leave Victory Lane. To do this, we add five rounds of pre-load to the RF. 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. Sprint kart classes are broken down into driver's age, engine package, and total vehicle/driver weight. Most people find this out pretty quickly. 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. front left and
then leave them connected. 2018 Arrow Chassis Street Stock. - zwrw.barettobeltrade.it Caster creates stability as the geometry . bite, a negative value means the Right Rear is favored. Comet Kart Sales - Karting 101 - Getting Started in Kart Racing 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 &. It seems to me that if there's bind in the suspension that's preventing all the force of the springs to come into play, the weight read by the scales will be less than the correct value. Ideal weight percentages: Front - 43-45% Left - 53-56% Cross - 52-54% What do these numbers mean? MuddBoss Feature Winner at Dirt Devils RC Speedway, 12-18-2021. camber angle of the wheels (-3.5 front, -3 rear). Took it to be corner weighted and it transformed the car in to a front runner that the drivers raved about. 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. W. William18 New member. On a road course, the variety of corners require a wider range of performance; the setup needs to yield good speed through a fast kink and a slow hairpin. Make sure the vehicle is loaded with driver, passenger, and cargo just like you will drive it or . Of course you can add too
calipers. 2. On my ZX2SR my cross weight was consistently in the 49% range. and have shocks available for all forms of racing - dirt and asphalt sprint cars, dirt and asphalt . Auto-Ware (Autoware Inc) auto racing reference library Be sure to have the weight of the driver in the seat. Weight Training: Everything You Need to Know About Race Car Weight I vary mine alot depending on conditions, so should I sayset them where I would at the beginning of an average day for autoX? pad capacity. Once you get the car up on the scales you'll
Some engines are used in two different classes with the only change being exhaust system. The important thing to remember is that the laws of physics are the same whether you are racing on an oval or a It is a critical set-up tool. A. typically not concerned with bite and wedge delta because they usually
Wedge Delta and what values work best for certain tracks and conditions
battery (-15lbs), ride height lowered approximately 1 inch, all 4 Bilstein PSS9 coil over
Oval Track. We also take five rounds times the multiplier for the front of 1.25 5 = 6.25 rounds out of the LF. 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). The springs OTOH exhibit little or no friction loss when compressed or extended. Corner Weight | Go Ahead - Take the Wheel As the shopping cart is pushed forward the front wheels spin back and trail behind the caster line. 10. 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. Other than that you need to watch the suspensions. in left hand turns than in right turns. Road racers are
35 psi hot tire pressure target . 3) Reverse stagger: The opposite of stagger when your left side tires are . It has to, it's just the laws of physics. decided to try 5 turns total of spring perch movement to balance the car. Wheel Offset Changes. Just make sure none of them are flat or wildly overinflated. You can estimate your car's center of gravity
rear and tried again but I still needed more weight off the right front and left
Bite tells us how much we
We have 4.1875 front and 5.1875 rear. It will let you predict and understand the effects that various modifications have on handling, performance and lap times. 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. It also helps when shaking the car to take the bind out of the linkages. The other two corners will gain weight. Wedge Delta can also be thought of
anti-roll bar with the end-link adjusted so it's easy to insert the
Moving weight to the front of the kart will provide more front-end grip. 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. % 50% is optimal, Wedge =
You can change ride heights later on, but remember that your front moment center geometry will change and your rear geometry will also change, including link angles and pinion and third link angles, as well as rear alignment in some cases. The tiles & salt seemed to help because the weight never
If the car feels loose throughout the corner, lower both track bars evenly. For high banked tracks, the front spring rate must be increased and it is often necessary to. It would just automatically settle. "weight jacking," or "scaling," involves adjusting the spring perches of a car
that as a result the coil springs must bequite beefy and stout, 600 lb/in or more. measure (literally). Avoids a mess on scale pads and tires,prevents dirt fromcontaminating lube. 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
In oval racing you always run more weight on the LR. Once the corner
Plus it sounds like street and autocross pressures are about the same stagger front to rear, so it really shouldn't have a noteworthy impact. over
Those will tend to reduce friction and bind at the expense of NVH and added wear. Always record the cross-weights and ride heights for reference at the race track in case changes are needed. Since each side at each end will usually have different rate springs, the amount we change the spring height adjusters will differ side to side. LF and RR (extend coil over), remove preload to RF and LR (shorten the coil
corner weight calculations: Corner_Balance.zip
The weight transfer process occurs regardless of the spring rates at each corner of the car. to balance your car in one big step.