slowerF500 Rotax 493 and 593 intake boots: removed Moto Tassinari V3124-873B-2 option for non-HO, corrected BPP part numbers.
As printed in Fastrack
In F500, GCR section 9.1.1.D.14.A, change as follows: “Carburetor mounting must be of individual runners, with no balance pipes and no plenums unless fitted as standard as on the Rotax 493 and 593 engines. The use of the intake plenum/resonator on the 493 and 593 engines is optional. If the intake resonator is removed the resulting holes MUST be completely plugged and the plugs must be held in place by appropriate clamps. Plugs may be of any material and must serve no other purpose than to plug the holes originally intended for the resonator. 38mm i Intake boots, BPP 420867860 (last 6 digits 867860 are embossed on the boot), BPP 420867862 1 (last 6 digits 867862 1 are embossed on the boot), or Kimpex 07-100-33, or Moto Tassinari V-Force 3 Reed Valve System V3124-873B-2 must be used for the 493 and 593 non-HO engines. Moto Tassinari V-Force V3120-794A-2 Reed Valve System may be used with any
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allowed intake boot on the 493 and 593 non-HO engines. 38mm i Intake boots, BPP 420867882 (last 6 digits 867882 are embossed on the boot) or Moto Tassinari V-Force 3 Reed Valve System V3124-873B-2 must be used for the 2003 593 HO engine, and 38mm i ntake boots, BPP 420867879 (last 6 digits 867879 are embossed on the boot) or Moto Tassinari V-Force 3 Reed Valve System V3124-873B-2 must be used for the 2004-2007 593 HO engines. Supercharging, turbocharging, and direct fuel injection are prohibited.”
wordingF500 Rotax engines now permitted to use Ingi Tech Sparker ignition DCP-CDI-P2 as alternate ECU.
As printed in Fastrack
In F500, GCR section 9.1.1.D.14, add a new section as follows: "N. Alternate ECU for Rotax engines: The use of the Ingi Tech Sparker ignition part number DCP-CDI-P2 is permitted."
In F500, GCR section 9.1.1.D.15.G, add the following: "The exhaust system and exhaust manifold are unrestricted, within SCCA safety regulations, except that stepped diameter exhaust headers are not allowed. This prohibition does not include the exhaust flange area immediately adjacent to the cylinder head." In F500 Engine Table, Honda CBR600RR, Suzuki GSXR600, and Yamaha R6 spec lines, add the following: "Stepped diameter exhaust headers are not allowed"
593 carb boot availability and oil pump clarification
In F500, GCR section 9.1.1.D.14.A, change as follows: "Carburetor mounting shall must be of individual runners, with no balance pipes, and no plenums unless fitted as standard as on the Rotax 493 and 593 engines. The use of the intake plenum/resonator on the 493 and the 593 engines is optional. If the intake resonator is removed the resulting holes MUST be completely plugged and the plugs must be held in place by appropriate clamps. Plugs may be of any material and must serve no other purpose than to plug the holes originally intended for the resonator. 38mm intake boots, BPP 420867860 (last 6 digits 867860 are embossed on the boot), BPP 420867862 (last 6 digits 867862 are embossed on the boot), or Kimpex 07-100-33, or Moto Tassinari V-Force 3 Reed Valve System V3124-873B- 2 shall must be used for the 493 and 593 non-HO engines. 38mm intake boots, BPP 420867882 (last 6 digits 867882 are
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embossed on the boot) or Moto Tassinari V-Force 3 Reed Valve System V3124-873B-2 shall must be used for the 2003 593 HO engine, and 38mm intake boots, BPP 420867879 (last 6 digits 867879 are embossed on the boot) or Moto Tassinari V-Force 3 Reed Valve System V3124-873B-2 shall must be used for the 2004-2007 593 HO engines. Supercharging, turbocharging, and direct fuel injection are prohibited." In F500, GCR section 9.1.1.D.14, add a new section as follows: "M. The stock oil injection pump, oil lines, and control cables may be removed from all Rotax engines. The oil injection ports may be removed and plugged as necessary."
wordingF500 must install AIM part #X47KPFSOLO2R0 data box mount for Majors Races and Runoffs.
As printed in Fastrack
In F500, GCR section 9.1.1.D.19, change as follows: "All F500 cars competing in Majors Races and the Runoffs must have the AIM part #X47KPFSOLO2R0 data box mount installed on the vehicle to provide the necessary mounting of the AIM Solo or Solo 2 data box."
otherF5 cars must install AIM part #X47KPFSOLO2R0 data box mount for Majors Races and Runoffs.
As printed in Fastrack
In F5, GCR section 9.1.1.D, add a new section as follows: "19. All F5 cars competing in Majors Races and the Runoffs must have the AIM part #X47KPFSOLO2R0 data box mount installed on the vehicle to provide the necessary mounting of the AIM Solo or Solo 2 data box. The mounting surface is to be approximately oriented either horizontally or vertically either parallel or perpendicular to the longitudinal axis of the car and must be accessible from the exterior of the car with the driver on board -- it should have a view of the sky and not be located under carbon fiber or metallic bodywork. Sufficient space should be left between the mounting plate and the surface to which it is attached to permit the use of zip ties/tie straps to restrain the data box to the mounting plate. The purpose of this requirement is to allow the random placement of data boxes on cars on pre-grid by SCCA assigned personal and the collection of the box when the car exits
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the race track. Contact AIM and their distributors for direct purchase."
wordingF5 clarifies assisted shifting: mechanical only, no solenoids or air-shifters; throttle/ignition devices allowed if driver controls initiation.
As printed in Fastrack
In F5, GCR section 9.1.1.D.6.B.4, make changes as follows: "All gear changes must be initiated and made completed by the driver. Only mechanical gear shifting mechanisms are permitted. This may include cables, rods, or other mechanical linkage systems. All other shifting mechanisms are not permitted. This prohibition shall include electric solenoid shifters, air-shifters, etc. and other devices not mechanically actuated and controlled completely by the driver. Devices that allow pre-selected gear changes and closed-loop systems that use feedback from sensors to vary the timing of the gear selection process are also prohibited. Devices that interact with the throttle, ignition, or fuel system during a shift operation (for example: ignitions cuts, flat shifters, blippers) are permitted, but no such devices shall remove the driver's control of the gear change initiation, gear selection or
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completion. The burden of proving that a device is in compliance with this rule shall be upon the competitor."
In F5, GCR section 9.1.1.D.1, change as follows: "A class for single seat, open wheel, rigid limited suspension race cars using either a snowmobile-derived engine and drive components or a 600cc motorcycle engine."
cars addedF500 Rotax 593 HO engine added at 875 lbs with MA0242SP1020A or MA0242SP1063A restrictor.
As printed in Fastrack
In F500, GCR section 9.1.1.D.14, Snowmobile Derived Engines, add the following: "Rotax 593 in a carbureted, non-HO or HO version;" In F500, GCR section 9.1.1.D.14.A, add the following: "38mm intake boots, BPP 420867860 (last 6 digits 867860 are embossed on the boot), BPP 420867862 (last 6 digits 867862 are embossed on the boot), or Kimpex 07-100-33, shall be used for the 493 and 593 non-HO engines. 38mm intake boots, BPP 420867882 (last 6 digits 867882 are embossed on the boot) shall be used for the 2003 593 HO engine, and BPP 420867879 (last 6 digits 867879 are embossed on the boot) shall be used for the 2004-2007 593 HO engines." In F500, GCR section 9.1.1.D.14.I.3, add the following:
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"Rotax 593 non-HO (0.010" overbore): Rotax P/N 420889171" In F500, GCR section 9.1.1.D.14.J.3, add the following: "Rotax 593 non-HO engine only: Rotax OEM 0.010" overbore piston (P/N 420889171)." In F500, GCR section 9.1.1.D.14.K, add the following: "Rotax 593 non-HO engine only:" In F500 Engine Table, add the following: F500 Version/Model Weight (lbs) Inlet Restrictor Outlet Restriction Notes Rotax 593* Carbureted HO version (03-07) 875 MA0242SP1020A or MA0242SP1063A Y-pipe exhaust manifold and single expansion chamber (ref 9.1.1.D.14.B) Note 1 and 4. Restrictor size and type is to be displayed by the following designation: 593 RSTR
wordingF5 request to adjust external jetting devices cockpit control denied by Club Racing Board.
As printed in Fastrack
Thank you for your letter. After reviewing the response to the WDYT published in the May 2020 Fastrack Minutes, the Club Racing Board does not recommend this change.
slowerF500 Honda CBR600RR, Suzuki GSXR600, Yamaha R6 restrictor reduced from 29mm to 28mm Flat Plate Intake.
As printed in Fastrack
In the F500 engine table, change the restrictor as follows: Honda CBR600RR (03-13): "29 28mm Flat Plate Intake Restrictor" In the F500 engine table, change the restrictor as follows: Suzuki GSXR600 (03-13): "29 28mm Flat Plate Intake Restrictor" In the F500 engine table, change the restrictor as follows: Yamaha R6 (03-13): "29 28mm Flat Plate Intake Restrictor" Table 1 Car Engine Wheel
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Width (in) ± .060 Aero Transmission Weight Notes USF2000 Tube Frame 2.0 Liter Mazda MZR See notes See notes See notes See notes Car must comply with the 2012 Pro USF2000 rules. Competitors must have the current rules in their possession and present them upon request. The following sections of the 2012 Pro rules do not apply: 14.1.1 thru 14.1.4; 14.12.2 thru 14.12.13; 14.13.1; 14.13.2; 14.13.5; 14.18 in its entirety; 14.19 in its entirety; 14.27 in its entirety; 13.34 in its entirety
Request for Weight Increase for Motorcycle Powered Cars
slowerF500 Honda CBR600RR, Suzuki GSXR600, and Yamaha R6 (03-13) minimum weight increases from 875 to 900 lbs.
As printed in Fastrack
In the F500 engine table, change the weight as follows: Honda CBR600RR (03-13): "875 900" In the F500 engine table, change the weight as follows: Suzuki GSXR600 (03-13): "875 900" In the F500 engine table, change the weight as follows: Yamaha R6 (03-13): "875 900"
Thank you for your letter. We have received a number of letters in 2022 on the topic of the balance of performance between the two- and four-stroke F500 platforms. Please see, for example, the response to letter #32813 in the September 2022 Fastrack. That response outlines how we have been, and will be, monitoring performance between F500 platforms using the AiM devices to determine performance balance, leading to potential adjustments. If adjustment were indicated and generally accepted weight or restrictor adjustments were considered inadequate or ineffective, the Club Racing Board would consider your suggestion to limit the two-strokes to specifically approved parts to reduce performance. With regard to your recommendation to make two-strokes more attractive to newcomers, the Club Racing Board believes this is a good idea, but it would be best accomplished by class stakeholders and not by rules adjustments. Stakeholders in other classes
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have put together class-specific documents to help improve car counts as well as the overall racing experience. These documents typically include tech tips, setup tips, parts suppliers, available parts, etc. These kinds of materials help both newcomers as well as current competitors. There are a number of places where newcomers can get advice on initial setup and parts selection and availability. These include the “SCCA F500 & FModified” Facebook page, as well as the following suppliers who offered to be contacted by newcomers for introductory advice and guidance: - Dan McMahan, Atlanta, GA, 678-836-6467 (motorcycle engine conversions / support various cars) - Leon Mitchell, Mitchell Racing Services, Indianapolis, IN, 317-490-6514. (Scorpion supplier / support various cars) - Mike Quadrini, QRE, New York, NY, 231-590-903 (Invader builder/supplier / general support ) - Mel Winnie, M&M Sports Center, Michigan, Bus: 231-369-4300, Mobile: 231-590-9003 (two stroke engines / general support)
Request to Equal the Weight Between the 593HO and the MC Cars
Thank you for your letter. With regard to the advertiser's claims of improved performance, on-track data will be obtained at the 2022 Runoffs from various platforms, including any two-cycle cars equipped with the Moto Tassinari parts, and adjustments will be made for 2023 if warranted by the data. With regard to the carb boots, please see the response to letter #33028 in this Fastrack's Technical Bulletin.
Thank you for your letter. With regard to the concerns of potential increased performance, on-track data will be obtained at the 2022 Runoffs from various platforms, including any two-cycle cars equipped with the Moto Tassinari parts, and adjustments will be made for 2023 if warranted by the data. Please see the response to letter #33028 in this Fastrack's Technical Bulletin.
Change the Weight of the 4 Cycle F600 Cars Back to 875 Lb.
Thank you for your letter. While the supplied 2020 Runoffs results data indicated certain locations where the 593 non-HO's speeds were slightly higher than those of the 600cc, analysis of the data obtained from cars equipped with AiM data boxes during that event did not show that the 593 non-HO had a clear performance advantage over two 600cc cars in those sectors. AiM data was recently obtained from various platforms at the 2022 June Sprints, and a careful review of this data also did not show that the two-cycle platform had a clear performance advantage over the four-cycle platform. Analysis of the June Sprints data did show that one car may have an apparently significant but brief advantage over another car at a specific location within a sector, while not having an overall performance advantage over the other car in that sector. This kind of brief advantage most often results from a difference in powertrain characteristics of the two-cycle and four-cycle platforms. AiM data will be obtained
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from various platforms during the 2022 Runoffs, including any two-cycle cars equipped with the Moto Tassinari part, and adjustments will be made for 2023 if warranted by the data.
Moto Tassinari V-Force 3 Reed Valve System V3124-873B2
Thank you for your letter. Neither the race results nor the AiM data from the 2020 Runoffs shows that the two-cycle platform had a performance advantage over the four-cycle platform. On-track data will be obtained at the June Sprints and Runoffs from various platforms, including any two-cycle cars equipped with the Moto Tassinari part, and adjustments will be made for 2023 if warranted by the data.
In F500, GCR section 9.1.1.D, change as follows: "FORMULA 500 600 PREPARATION RULES" "Formula 500 600 (F500 600) Specifications" "9.1.1. F500 600 Spec Lines" In F500, GCR section 9.1.1.D.1, change as follows: "Formula 500 600 is a restricted class." In F500, GCR section 9.1.1.D.14, change as follows: "The AMW engine approved for F500 600 use shall must be the AMW model no. 250-2 RC2, two-cylinder, two-cycle, liquid-
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cooled, reed-valve engine with a nominal bore and stroke of 72mm x 61mm and a displacement of 497cc." In F500, GCR section 9.1.1.D.19, change as follows: "All F500 600 cars competing in Majors Races and the Runoffs must have the AIM part #X47KPFSOLO2R0 data box mount installed on the vehicle to provide the necessary mounting of the AIM Solo or Solo 2 data box." In F500 engine table, change as follows: "F500 600" In GCR CONTENTS, change as follows: "FORMULA 500 600 PREPARATION RULES" In Racing Rules and Procedures, GCR section 6.4.4, change as follows: "In all SCCA competitions, engines shall must be started by the driver sitting in the normal driving position, except F500 600 cars with two-cycle engines, using an on-board or supplemental power supply." In Cars and Equipment, GCR section 9.1.1, change as follows: "Formula 500 600 (F5 6)" In Cars and Equipment, GCR section 9.3.12, change as follows: "On all carburetors (except SU, Sports Racing cars with motorcycle-type carburetors, Formula 500 F600 two-cycle Mikuni VM38, and F600 motorcycle-engine cars) equipped with a non-threaded fuel inlet fitting, the fitting shall must be replaced by drilling and tapping the carburetor body for a threaded fitting." In Cars and Equipment, GCR section 9.4.5.C.1, change as follows: "F500 600 cars up to 875 900 pounds may use 1020 DOM mild steel roll cage bracing with a 1.0" diameter by .065 wall thickness." In Cars and Equipment, GCR section 9.4.5.C.2, change as follows: "F500 600 cars up to 875 900 pounds may use 1020 DOM mild steel roll cage bracing with a 1.0" diameter by .065 wall thickness." In Appendix B, GCR section 1.4.2.D, change as follows: "It is preferable not to combine FA, FB, FC, FE, and FM with FV and/or F500 600. FV may be combined with F500 600." In P2 Table 1, AMAC, Asteck, Cheetah, Decker, Fox, LeGrand, Converted F500 cars spec line, change the marque as follows: "Converted F500 600 cars" In P2 Table 1, AMAC, Asteck, Cheetah, Decker, Fox, LeGrand, Converted F500 cars spec line, change the notes as follows: "Converted F500 600 cars must retain suspension compliant with F500 600 requirements and meet all P2 non-spec line requirements except minimum width is 55 inches."
#31896 (Keith Joslyn) Should the class name be changed to F600
Thank you for your letter. These changes are not recommended. The Club Racing Board will continue to monitor class performance and will make adjustments if warranted by the data.
Thank you for your letter. These changes are not recommended. The Club Racing Board will continue to monitor class performance and will make adjustments if warranted by the data.
Thank you for your letter. These changes are not recommended. The Club Racing Board will continue to monitor class performance and will make adjustments if warranted by the data.
Thank you for your letter. These changes are not recommended. The Club Racing Board will continue to monitor class performance and will make adjustments if warranted by the data.
Thank you for your letter. The Club Racing Board is seeking input on whether a prohibition of tire warmers should apply to all classes effective 1/1/2022. The request is not specific to the F500 class. Please see the response to letter #30855 in the October 2021 Fastrack Minutes. Regarding the issue of assisted shifting systems, please see the response to letter #30871 in the August 2021 Fastrack Technical Bulletin.
Thank you for your letter. The Club Racing Board is seeking input on whether a prohibition of tire warmers should apply to all classes effective 1/1/2022. The request is not specific to the F500 class. Please see the response to letter #30855 in the October 2021 Fastrack Minutes. Regarding the issue of assisted shifting systems, please see the response to letter #30871 in the August 2021 Fastrack Technical Bulletin.
Thank you for your letter. The Club Racing Board does not recommend this change because the rules already allow engine vibration isolation. The language is adequate as written.
Thank you for your letter. The Club Racing Board does not recommend these changes. The Rotax 593 HO's minimum weight was recently established using comparative dyno data for the 593 HO and 593 non-HO engines, and time needs to be afforded this determination in order to meaningfully evaluate the 593 HO's competitiveness relative to the other platforms. On-track data obtained at the 2020 National Championship Runoffs and the 2021 June Sprints Super Tour event does not support the requested weight reduction for the Rotax 593 non-HO platform.
Thank you for your letter. The Club Racing Board does not recommend this change. On-track data obtained at the 2020 National Championship Runoffs and the 2021 June Sprints Super Tour event does not support a reduction of the minimum weight for 600cc motorcycle engine cars. The Club Racing Board will continue to monitor class performance and make appropriate, data-based adjustments as necessary.
Thank you for your letter. The Club Racing Board does not recommend this change. Please see the response to letter #30871 in this Fastrack's Technical Bulletin.
Thank you for your letter. The Club Racing Board does not recommend this change. Dyno data for the Rotax 593 HO and non-HO engines does not show a ten horsepower difference between the engines, and on-track data obtained at the 2020 National Championship Runoffs and the 2021 June Sprints Super Tour event does not support removal of the 593 non-HO's intake restrictors.
Thank you for your letter. The Club Racing Board does not recommend this change. No evidence of a need for stepped headers has been provided, nor has comparative dyno data been submitted. Without such information, the Club Racing Board cannot justify removal of the prohibition of stepped headers, which would almost certainly be perceived as a benefit to cars with 600cc motorcycle engines.
Thank you for your letter. The Club Racing Board does not recommend these changes. At the 2020 Runoffs at Road America, a two-cycle car qualified second fastest (0.096sec off pole position), set the fastest lap of the race (by 0.152sec), and finished 0.584sec behind the winning car. Please see also the responses to letters #28677 and #28673 in the April 2020 Fastrack Minutes, letter #28068 in the February 2020 Fastrack Minutes, and letter #27515 in the December 2019 Fastrack Minutes.
Thank you for your letter. The Club Racing Board does not recommend this change because it would effectively require competitors to lengthen the wheelbase of all existing cars. Please see the response to letter #27420 in the October 2019 Fastrack Minutes.
Thank you for your letter. These changes are not recommended. The Club Racing Board has adjusted the minimum weight and inlet restrictor on 600cc motorcycle-engine cars and the Board of Directors has CLUB RACING BOARD approved the use of external jetting devices on two-cycle cars. Time needs to be afforded these changes to evaluate their effectiveness in promoting competition between the two platforms.
Thank you for your letter. The Club Racing Board does not recommend this change. Please see the response to letter #27515 in the December 2019 Fastrack Minutes and the response to letter #27883 in the January 2020 Fastrack Technical Bulletin.
Thank you for your letter. The Club Racing Board does not recommend this change. Please see the response to letter #27515 in the December 2019 Fastrack Minutes.
Request to clarify rule change procedure for F500 rear spoiler
Thank you for your letter. The Club Racing Board recommended this rule change in March 2018. Please see the response to letter #23870, April 2018 Fastrack Minutes. After the proper comment period, the Board of Directors approved the proposed change as recommended in its August 2018 meeting. Please see the response to letter #23870, October 2018 Fastrack Board of Directors Minutes. The rule change went into effect January 1, 2019.
Thank you for your letter. The Club Racing Board does not recommend these changes. The Formula/Sports Racing Committee capably advises the Club Racing Board on matters relating to the F500 class and there is no plan to create an F500 ad hoc committee. The Club Racing Board will continue to monitor class performance and will make appropriate, data-based adjustments as necessary.
Request to remove motorcycle-powered cars from the class
Thank you for your letter. This change is not recommended. The Club Racing Board recently added 25 lbs. to the 4-stroke cars and recommended allowing the 2-stroke cars to use external jetting devices; the latter has not yet been seen in competition and time needs to be afforded these changes to determine if they will be effective in increasing 2-stroke participation. In addition, the F500 class participation numbers show that the 4-stroke cars could not meet a 4.0 participation average as a separate class, and there is no basis for concluding that the 2-stroke cars could meet a 4.0 participation average if the 4- stroke cars were removed from the class. The Club Racing Board will continue to monitor class performance and will make appropriate adjustments as necessary.
Thank you for your letter. The Club Racing Board does not recommend this change because it would effectively require competitors to lengthen the wheelbase of all existing cars.
Allow External Jetting Devices on F500 Carbureted Engines
In F500, GCR section 9.1.1.D.14.A, add the following: "Carburetors: The induction system is restricted to two (2) 38mm Mikuni VM 38 round slide carburetors (except AMW). No modifications are permitted to the carburetor bodies. The use of any jets or jet needles is permitted. External carburetor jetting devices such as Mikuni Power Jet, Thunder PowerJet, Dial-A-Jet, IntelAJet, or other similar devices may be used, provided they are plumbed to the float bowl and body of the carburetor for which they are installed. Cockpit adjustment of external jetting devices is prohibited."
Thank you for your letter. The Club Racing Board does not recommend changing the implementation date because this adjustment does not represent a significant change for most cars.
Weight Increase of Motorcycle Powered Cars In Lieu of Restrictor
Thank you for your letter. Sleeving a throttle body to assist air flow through a flat plate intake restrictor is not permitted. F500 is a restricted class, and any allowable modifications, changes, or additions are stated in the rules. The rules applicable to 600cc motorcycle engines state that "Fuel injection, if used, must be stock and unmodified for the model and year of the engine that is used."
Request for Cockpit Adjustment of External Jetting Devices
593, Not 494 Thank you for your letter. Please see the responses to letter #26326, March 2019 Fastrack Minutes, and letter #25815, February 2019 Fastrack Minutes.
Thank you for your letter. The Club Racing Board does not recommend this change. If there is an issue with supply of the current exhaust header or an alternate design is available at a lower cost than the existing header, please submit supporting documentation and the Club Racing Board will consider your request.
Request to allow CBR600F4i and CBR600F engines in F5
Thank you for your letter. The Club Racing Board does not recommend this change because an adequate supply of the approved engines is currently available.
Thank you for your letter. The Club Racing Board does not recommend these changes. Please see the response to letter #25815, February 2019 Fastrack Minutes.