eighing race cars is the one check that will happen to all cars after a qualifying or race session. In many classes a pound or two of weight can be the difference between winning or loosing. A little care taken during the weighing process can result in consistent measurements and increased confidence from the drivers. The procedures for platform scales are similar to the procedures listed here, see the GCR for the differences. 1. GCR Sections 1. CONTROLLING COMPETITION 1.2. SCCA GENERAL COMPETITION RULES 1.2.3. Interpreting and Applying the GCR A. Interpreting the GCR shall not be strained or tortured and applying the GCR shall be logical, remembering that the GCR cannot specifically cover all possible situations. ords such as shall or shall not, will or will not, can not, may not, are or must are mandatory; and words such as may and should are permissive. C. Conflicts among or between portions of the GCR are handled as follows: 1. The Category Rules take precedence over the General Technical Specifications. 2. Specific class rules in the Category Section of the GCR shall take precedence over the general Category Rules and the General Technical Specifications. 3. Any item not addressed in the Category Rules is controlled by the General Technical Specifications. The specification line for a particular car takes precedence over the specific class rules, the general Category Rules and the General Technical Specifications. D. The interpretation and application of the GCR by SCCA officials is final and binding. To promote the sport of automobile competition; to achieve prompt finality in competition results; and to recognize the numerous benefits to them, all members expressly agree that:... 5. OFFICIALS, THEIR DUTIES, OPERATING PROCEDURES, AND EQUIPMENT 5.9. TECHNICAL AND SAFETY INSPECTION 5.9.3. Impound C. Minimum Impound Inspection Unless otherwise specified in the Supplemental Regulations, the first 3 finishers in each class shall be immediately impounded for a minimum of 30 minutes after their race is completed. The Race Director or the Chief Steward may direct that additional finishers in any class may likewise be impounded. It is the driver s responsibility to know his finishing position and present his car to impound immediately, without going to the paddock. Failure to do so promptly will be reported to the Race Director or Chief Steward, and may result in penalty. For each impounded car, the weight and other items appropriate for the class may be inspected, as agreed upon by the Race Director or Chief Steward and the Series Chief Tech inspector or Chief Technical Inspector. The Race Director or Chief Steward may also order that a wheel or intake choke(s) or restrictors be removed during impound for inspection. These inspections are not subject to the fees outlined in 5.12.3.C.5. Additional inspections may be conducted through the protest procedures outlined in 8.3.3. If there is any doubt about the weight, the car must be weighed in both directions. A car that is underweight in impound will be reported to the Race Director or Chief Steward, is subject to penalty, and the weight will be noted on the next page of the Vehicle Logbook. The car must be weighed at the next event and must meet the proper minimum weight before being allowed to qualify. Updated through March 2017 Fastrack www.scca-milwaukee.org 1 Content: 2017 SCCA & Layout: 2017 Mark Troemel
The Series Chief Tech Inspector or Chief Technical Inspector will report any questions or doubts about a car s compliance to the Race Director or Chief Steward. 5.9.4. Official Scales A. The scales at the event are the official scales for the event. The Supplemental Regulations will include the hours scales will be available for drivers to weigh their cars. B. The following scale configurations are acceptable: platform scales, individual scales that weigh 1 axle (2 wheels) at a time, or 4 individual scale pads that each weigh a single wheel. If all 4 wheels cannot be weighed simultaneously, the driver must be weighed separately from the car. C. Certification Scales must be certified, as follows: 1. On-site certification by a commercial scale service within one calendar year prior to the event, OR 2. Use at the track of calibration weights, totaling 100 pounds up to 250 pounds total as recommended by the scale manufacturer, or minimum 250 pounds total if no recommendation is provided by the scale manufacturer for individual wheel scales; minimum 750 pounds total for platform scales. here applicable, the calibration recommendation by the scale manufacturer (e.g., a manual or letter from the manufacturer) must be available at all times during an event where the scales are in use. 9. CARS AND EQUIPMENT 9.3. GENERAL TECHNICAL AND SAFETY SPECIFICATIONS 9.3.49. EIGHT All cars shall meet or exceed the minimum weight specified with driver, exactly as they come off the race circuit, at the conclusion of any race or qualifying session APPENDIX G. FACTS, FORMULAS, AND MEASUREMENT STANDARDS 2. MEASUREMENT STANDARDS The following specifications shall meet the standards set below unless otherwise specified or unrestricted in the individual category or class preparation rules. Any specification not listed herein shall meet stock factory specifications unless otherwise specified or unrestricted in the individual category or class preparation rules. For these specifications, the tolerance shall be equivalent to ½ of the final digit of the specification (e.g..01 tolerance equals +/-.005 ). Absolute maximum means tolerances of +0.000 inches or +0.00 millimeters. Absolute minimum means a tolerance of -0.000 inches or -0.00 millimeters. Measuring devices available to scrutineers differ from location to location so it is the responsibility of the driver to insure that measurements comply with these rules. 1. eight is absolute minimum. 2. Determining Car eight Some classes have weight modifiers. Most weight modifiers add or remove weight in pounds. Other weight modifiers add or remove a percentage of the weight. Calculate the weight in the order listed below: 1. Base eight +/- engine modifier(s) = Adjusted eight 2. Adjusted eight +/- chassis modifier(s) = Minimum eight Updated through March 2017 Fastrack www.scca-milwaukee.org 2 Content: 2017 SCCA & Layout: 2017 Mark Troemel
3. Recommended eighing Processes hen eighing 1 Axle at a Time Consistency in our weighing process should reduce the amount of weight issues. Do not discuss the results with anyone other than the driver or entrant. A. Setting Up the Scales 1. Place the scale pads on the shims in the scale pit making sure to remove all debris. a. Use one of the extra scale pads to the side of the scale pit for weighing the driver. 2. Run the cables from the scale head to the scale pads making sure that the left and right cables attach to the scale pad in the appropriate location. Use of the front or rear set of cables doesn t matter as long as the fronts or rears are used together. a. Run either of the extra cables to the scale pad for the driver making sure not to create a tripping hazard. 3. Do not allow the driver to drive the car on or off of the scales. 4. Make sure the scales are zeroed. 5. Get the driver out of the car before placing the car on the scales except for TA2 cars in GT2. 6. Straighten the steering wheel and do not turn the steering wheel between axles. 7. Align the center of the scale pad to the center of the tire. 8. Roll the can on to the scales to the center of the scale pad. 3. Once all the connections are made turn on the scales. Allow them to warm up for at least one minute before proceeding. Allow longer warm up time on colder days. 4. Press ZERO on the scale head aka. zeroing the scales. 5. Certify the scales per GCR Section 5.9.4.C.2 at the beginning of each day by placing the test weights on the scales. If possible, replace any scale pads that do not accurately report the amount of test weights. Record the results, date, time, and scrutineers involved on the scale sheets. B. Scaling Procedure 1. Quickly look over the car for items left on or in the car like radios, tools, water bottles, etc... Also see that the driver s helmet that get weighed is the same one that is worn on the track. 2. Line up the car perpendicular to the scale pit if possible. 9. hen the first axle is weighed roll the car to the next axle being careful not to turn the steering wheel. Make sure the center of the scale pad aligns with the center of the tire and adjust if necessary. Don t forget that some cars, especially open wheel cars, have a wider front track than rear track. 10. eight the driver on a separate scale pad or on one of the pads used to weigh the car. 11. Add up the weights of each wheel and the driver for the total weight. If possible give a copy of the weight to the driver. C. Reweighing Procedures If a car needs to be reweighed the driver or entrant should be notified and only technical inspectors should handle the car. Try to have the Chief of Tech or Assistant Chief of Tech oversee the process. Verify the minimum weight required for the car and the driver can drink water but not soak their drivers suit with water. Updated through March 2017 Fastrack www.scca-milwaukee.org 3 Content: 2017 SCCA & Layout: 2017 Mark Troemel
1. Make sure that there are no stones, debris, or chunks of rubber in or on the scale pads and that the scale pads do not touch the sides of the scale pit or rock in the scale pit. 2. Zero the scales and close the garage doors. 3. Follow the same process above. If the car needs to be weighed a third time, turn it around and weight it in the opposite direction. Definitely have the Chief of Tech or Assistant Chief of Tech oversee the process and follow the process above. Steering while on scale pads Often what happens when we rush through weighing process. Car pushed onto scale pads with the steering wheel turned then straightened while on the scale pads. Each axle weighed separately and the driver weighed separately. 4. Various Configurations hile eighing 1 Axle at a Time Centered on the scale pad Each wheel centered left-to-right and front-to-back on the scale pad. Each axle weighed separately and the driver weighed separately. LF = 169 RF = 203 LR = 291 RR = 252 TOTAL = 1102 LF = 176 RF = 199 Forward and off to one side on the scale pad Each wheel located on the right front corner of the scale pad. Each axle weighed separately and the driver weighed separately. LR = 286 RR = 260 LF = 174 RF = 201 LR = 287 RR = 259 Updated through March 2017 Fastrack www.scca-milwaukee.org 4 Content: 2017 SCCA & Layout: 2017 Mark Troemel
One wheel off center on the scale pad Three wheels centered left-to-right and front-toback on the scale pads with one wheel centered front-to-back and off the side of the scale pad. Each axle weighed separately and the driver weighed separately. ith driver in car leaning forward Each wheel centered left-to-right and front-to-back on the scale pad. Each axle weighed separately and the driver weighed in the car and leaning forward for the front axle and sitting back for the back axle. LF = 176 RF = 199 LF = 240 RF = 260 LR = 286 RR = 260 LR = 320 RR = 295 TOTAL = 1115 ith driver in car Each wheel centered left-to-right and front-to-back on the scale pad. Each axle weighed separately and the driver weighed in the car. LF = 237 RF = 256 LR = 320 RR = 295 Updated through March 2017 Fastrack www.scca-milwaukee.org 5 Content: 2017 SCCA & Layout: 2017 Mark Troemel
Debris in the scale pad M Each wheel centered left-to-right and front-to-back on the scale pad. Each axle weighed separately and the driver weighed separately. Gravel wedged in right rear scale pad. LF = 175 RF = 199 LR = 286 RR = 229 TOTAL = 1076 Thank you to Lindstrand Motorsports, Inc. for letting us play with one of their cars on our scales in their shop. Updated through March 2017 Fastrack www.scca-milwaukee.org 6 Content: 2017 SCCA & Layout: 2017 Mark Troemel