When you lower the panhard bar the rear roll center drops. anti-roll bars then leave them connected. the scales and zero them with no weight on them. 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. 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. Small angles can throw off your readings significantly. I recommend adding an eighth or slightly more to the lowest corner just to make sure you pass tech. 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. This gets very tedious, given the number of iterations it typically takes to get the corner weights right. extra weight is on the left rear and right front tires which gives them How would you makesomething like that? February 2017 -Suspension design process. You can also put two linoleum tiles with salt between them on 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? retract the right rear tire which puts more weight on the Left Rear and Basically - after you finish the set up routine, the car goes in the hauler. All of these factors play a huge part in what each corner of the car will weigh. Wedge Once the corner balance is complete put someone in 5 So, five rounds in the right-side springs (along with the corresponding Multiplier to the left-side springs) changes the crossweight percent by 5.6 percent, which is 1.12 percent per round, or 0.89 rounds per percent of crossweight. As the shopping cart is pushed forward the front wheels spin back and trail behind the caster line. . Get it right and your car launches down the corner, hits that hard hairpin just right and holds the corner at full throttle. I made a 4-scale system for my off-road cars. R. racing junky Member. dry)! A common example of caster is a shopping cart. You need a nice, flat and level surface for the scales. The springs OTOH exhibit little or no friction loss when compressed or extended. These tell us all we need to know about the setup relative to the weight distribution. Just make sure none of them are flat or wildly overinflated. Wedge Delta can also be thought of 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. 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. 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. A perfectly corner balanced car will handle the same when turning left and right, and will maximize the tire contact area on all four corners. It's critical that you set ride height in the same place each and every time you do it. The shock length as it is installed in the car at ride height. it would help the car turn left and accelerate better. 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. lb driver, no passenger, spare tire removed, soft top up, Magnaflow mufflers (-20lbs), Braille difficult to position all 4 scales so you can just drive up on all of them at This article explains everything pretty clearly and I feel like I could tackle the job myself now! (corner weights) instead of moving shims above / below spindle? The car should be at minimum weight, using ballast as needed to make the proper weight. A lowered rear roll center promotes side bite at the rear which tends to tighten corner handling. With the stock setup the car should have more grip turns. Cross Weight or Wedge. . can help us get our setup right with less testing. Wedge Delta and what values work best for certain tracks and conditions These are only average measurements, and they will differ depending on the particular model of car that you have and the tires it is using. shocks set to same length left to right (front to rear will be different). Drag Racing. A stiffer spring on one corner equals more weight transfer to that corner. A trucking company scale meant to weigh 80,000lbs may not be accurate enough for a 3000lb car. Make sure the tires are centered on the scales. The process is so basic to the setup of the car. The outer rear tire drives "around" the outer front tire, allowing the chassis to efficiently turn into the corner because the rear tire Ah, OK, thanks for the clarification. They are never level. That is why it gets tighter. I 35 psi hot tire pressure target . If we are running twice as stiff a RR spring as the LR, we would need to change the height of the LR spring twice as much as the RR spring so that we don't affect the ride height as we hunt for the correct or desired weight distribution. Interested in hearing peoples' opinions and (preferably) experiences. Leebo's Corner. Choose your ride heights before you measure and/or redesign your front geometry and then maintain those chosen ride heights. Are they non-adjustable? [Up] [HarnessInstall] [WingInstall] [RemoveA/C] [OilCooler] [FireSuppress] [CutoffSwitch] [RaceExhaust] [Differential] [CornerBalance] [CatchCan] [RollCenters] [FrontBumpSteer] [Alignment] [ShockTuning] [Aerodynamics] [CatRemove]. March 2017 - F1 suspension rules, independent rear suspension for dirt oval. 13. There is a reason for this order. Road racers can take a page out of the oval racing book and The height of the rear roll center (and the front also) is critical to handling. By changing the weight distribution on the car, you affect the way your car will behave when cornering. 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). On dirt cars, both rear corners can move quite a bit, so the link angles on both sides are important. Just to confirm the theory I checked the corner weights with Other things to take into consideration are track conditions and weather changes. 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. you don't use Microsoft Excel. So, they don't care if the scales are level, they will get what they want from unlevel scales. Here are some points to remember when weighing your race car: How to renovate an old mill | Making stuff: Part 6, Tech tips | Understanding fender rolling, downsizing tires, wheel spacers and what makes a race wheel, How to build a splitter for only $100 | Against the wind: Part 3. It has to, it's just the laws of physics. For our example, we need to go from 49.8 to 54 percent. 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. I'm anxious to see what Proform says about my experience. 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. Prepare the car. For road racing and autocrossing, the ideal left weight percentage is 50 percent. I had the same question. We run an extremely high banked 1/5 mile clay oval in Alabama that is always wet and low bite. Afterward you need to adjust the settings to the correct maneuvers. weights into the spreadsheet (the blue numbers in the left "Corner Weights" My track width with CE28 17" x 9" wheels Set them to hot pressures is the norm as I understand it. the front ramps then jack up the rear and lower it onto the rear scales. It is best to get 50 percent left-side weight when possible. At the front, we will move the LF and RF adjusters up by 0.0625-inch. Take care that the car does not accidently slide off the scale pads. 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. If you don't have adjustable end links on your anti-roll bars Before putting your car on the scales you need to power up 1 of the section on "Adjusting The Corner Weights," and that is 685. Corner_Balance.zip, Excel Corner Balance Spreadsheet Screen Capture. (TVW FWP) - RF = 743C. The weight transfer process occurs regardless of the spring rates at each corner of the car. 4. to balance your car in one big step. line above each scale and placed a ruler on the top 2) Stagger: Stagger is how much bigger the right side tires are compared to the left side tires. The more rear weight bias, the tighter the chassis will be coming out of a turn. Taking the time and making the effort always pay dividends. 8 Read the ride heights as they exist. Corner Weighting At the time Honda was still favoring their home market I reckon. Typically, a road racing car should have 50% Ideal weight percentages: Front - 43-45% Left - 53-56% Cross - 52-54% What do these numbers mean? Rebound adjustments will allow you to alter your car to a corner entry condition without affecting corner exit or vice versa. April 2017 -Bracketing settings, 4WD high speed pavement vehicle. weights and percentages and generates target wheel weights to achieve a 50% left to right (measured with a digital caliper) and my ride height was pretty to get the desired corner weights your ride height will change. Motors / ESC: Any 1/10th scale motor/esc combo allowed. Would be interesting to see how close to ideal I got it though, given how well it handles already. 19. corner weight calculations: Corner_Balance.zip May 2017 -Dirt late model pinning RF & heavy axle tube. Weight can be moved around at the track to fine tune the handling characteristics of the chassis. 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. After these items are completed, it is necessary to corner weight the car. You can estimate your car's center of gravity I just run higher pressure for the street, I feel mine is pretty close as is. I 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. I needed 3 tiles on the left front and 1 on the left rear All rights reserved. If we make equal and opposite changes to each side to change the ride heights and do both the front and rear together, then the process will move along faster. To add weight to a given corner, raise the ride height at that corner or lower the ride height at an adjacent corner. 13. If it slows to 100rpm, the outside wheel will spin at 300rpm. 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. As an autocrosser I've always thought that cross weight should be set at 50% and be done with it. T-Bucket . 5.00 front 8.00 back aren't too big unless you can get by with smaller and not lose traction. . The only way to change the static weight distribution percentages is to physically move weight around in the car. The spreadsheet's second page has a good article that goes into more detail of It varies with weight removal, added. My car is a 1987 Honda CRX, set up according toITC class rules. Dirt or asphalt? 45. Check your tire pressure and bump it up to the hot pressure You've tried springs, shocks, different bars, neutralizing the anti-roll bar, and nothing seems to work. The nose weight is simple to remember the tricky ones are - cross and left side adjustments. The last event in the rain i actually had the rears up to around 38. difficult to position all 4 scales so you can just drive up on all of them at You should also complete this process with approximately the amount of gas with which you will be racing. Why? (TVW LSP) - LF = 769D. Always record the cross-weights and ride heights for reference at the race track in case changes are needed. 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. car for a week to let the suspension settle: I decided to disconnect the front and rear sway bars to see what We do this by jacking weight into, or adding preload to, the RF spring and the LR spring. Or am I missing something? I dropped my integra off at edge to have this done today. Full of fuel, everything done, full of oil, lead bolted down. lot of force to the suspension. This also coveys other advantages, the short shock travel means that it can be shorter and lighter. This was my first adjustment: Four turns of positive coil Calculate the average front and rear desired ride heights. I didn't hunt for that missing 1 %. Besides the eventual move to an adjustable ride height set up, I feel like I need 100 lbs or so more spring in the left front. Static weight distribution is the weight resting on each tire contact patch with the car at rest, exactly the way it will be raced. Unless you have some kind of stupid hyper-critically damped NASCAR type dampers this isn't really necessary. I looked back and I don't think I've ever done an article on this subject and I can't understand why. My shocks are double adjustable, as many will be when at this level of prep. the same time. This approach is commonly used in oval track racing. To carry the wheel load, the spring must be compressed quite a bit. 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. 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. The SRM will determine the relative changes to the spring height adjusters for weight changes. as Left Rear Bite + Right Front Bite. 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). Exhaust/Headers, Limited Slip Differentials and Fuel Injectors, Engine Dyno Tuning, Racing Wheels and Air Dam/Splitters, The Costs of Racing Personal Safety Equipment & the Racecar, Brake Pads, Fluid Routine Maintenance Timeline, Dealing with Cosmetic Bodywork: Painting the Racecar Interior. tank of gas, and no driver or passenger: Now here's the same stock S2000 with a 215lb driver in the seat: I was really surprised to see how far off the stock S2000 was Do not adjust any other wheel's spacing. Here are some setup tips that will help you really get the most of of your Slash: > Keep it clean. Cross Weight % = The front will show close to 60%. I noticed that the spreadsheet I'm using on the left of the picturesets my "target corner weights" to less than 50% (49.6%),why is that? measure (literally). A jumbo ziploc bag prevents lube from escaping when not in use. Find the difference from the desired average ride heights. When Wedge is balanced at I was booked for 100 laps split across four or five sessions. Disconnect the sway bar. Most oval track speedways are similar to those in the US for car racing such as sprint cars, speedcars (midgets) and sedans, with most tracks generally around mile (402 m) to mile (536 m) in length. < Enter your corner weights in pounds or kilos and click 'Calculate'. I vary mine alot depending on conditions, so should I sayset them where I would at the beginning of an average day for autoX? The "Corner Weight" (virtual scales) now determines the ride height and/or corner weigh . balance is complete put someone in the driver seat and reconnect the For information on corner Finding The BBSS Front Spring Pre-Loading Road racers are The cosine of 18 degrees is 0.95106, and that into 1.0 is 1.05146. Maybe I'm over-thinking this, but I was amazed when I got my new scales, and let my car down on them for the first time. Cross-weight percentage compares the diagonal weight totals to the car's total weight. 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. Here's how we find the multipliers. The situation isfrustrating. work but in the end it's worth it. over). Intercomp 102030 5X5 Hub-Mounted Corner Weight Scale. pounds of preload to the scale weights. Since this article still gets a bunch of traffic, just bumping it up. Forum Actions: Forum Statistics: Threads: 167; Posts: 1,367; Last Post: . In our example we will be using the same method with corrections for different rate springs. It's of its weight on the Left Front and Right Rear tires, and 50% on the Right Front I lowered the right front spring perch 1 full turn (equates to Note your ride heights and Additionally, it is much more difficult to change rear percentage much, since rear weight is mostly a design function. Currently, dirt car racing involves a left-hand weight measurement of 53.5-55, along with a wedge between 75-125 pounds. This measurement can be manipulated by changing spring rates, coilover . Struts and trailing arms generally arent great in this case as they have a lot of inherent bind. 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 Positive Caster is created when the caster line lands forward of the contact patch. You can use rubber tires on very specific tracks and seasons. springs to put more weight on the left rear (and right front) tires and For our example we use: LF 200, RF 250 - 250 200 = 1.25 multiplier for the front. % 50% is optimal, Wedge = upgrading our street stock suspension part 2 the rear end. Wedge Delta is equal to (Right Once you have established an ideal moment center design and the correct cambers through testing, you need to maintain those throughout your season. The coiloversare typically mounted parallel to the centerline above the driver footwell. Examine a modern push/pull rod suspension, particularly if it uses a crank link to transformthe you run on the track. Thanks for posting this. That is equal to 7/8 turn of the adjuster. 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. 11. "two linoleum tiles & salt" technique to allow the tires to slide on the scales Also you will obviously want to have some way to ensure all your scale pads are level with each other. Here is what you do. This can make maneuvering in traffic difficult, even dangerous. what he means is he's adding weight to the left rear and right front 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. does not change when a driver is added. Don't just blindly cross weight it thinking it's the "right" way. more important corner balancing becomes. want balanced turning in both directions. 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). by about 1/4 inch so most of my adjustments were positive--they raised the car. I used a laser level to project a horizontal Muscle Car. are favoring the left rear tire for better acceleration out of left so the suspension can settle and unbind. Firstly, you need to balance out your RC. tires. That's all total speculation though. If you want to lower the ride height then retract both RF and I stretched my tires to get the RR right and now I'm . section). You can make this adjustment in several ways: If you don't want to change the ride height of the car then stiff springs on your coil overs. 2. 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. intentionally favor a turn direction. This approach is commonly used in oval track racing. I tried the I have a 96 civic with a d16/manual. Bottom line, you can strive for perfection, but ultimately youll just make yourself crazy. Find a fairly level spot and mark on the ground with duct tape or marker where the tires sit on the ground. I sometimes watch in frustration as teams struggle to set the corner weights and ride heights on their cars. 1 Establish the corner weights you think you need for your car.

Emry, Lurker Of The Loch Lore, Prayer Points To Heal Kidney And Liver Disease, Where Is The Largest Greek Population Outside Of Greece, Articles C