Competition Rules

Below you will find updated rules and guidelines for all ISSCA-sponsored events. For information on a specific event, please click the links below to be taken directly to that section.


The rules and/or regulations set forth herein are designed to provide for the orderly conduct of racing events and to establish minimum acceptable requirements for such events.  These rules shall govern the condition of all events, and by participating in these events, all participants are deemed to have complied with these rules.   NO EXPRESSED OR IMPLIED WARRANTY OF SAFETY SHALL RESULT FROM PUBLICATIONS OF OR COMPLIANCE WITH THESE RULES AND OR REGULATIONS.  They are intended as a guide for the conduct of the sport and are in no way a guarantee against injury or death to a participant, spectator, or official.

The race director shall be empowered to permit reasonable and appropriate deviation from any of the specifications herein or impose any further restrictions that in his/her opinion does not alter the minimum acceptable requirements.  NO EXPRESSED OR IMPLIED WARRANTY OF SAFETY SHALL RESULT FROM SUCH ALTERATION OF SPECIFICATIONS.  Any interpretation or deviation of these rules is left to the discretion of the officials. Their decision is final.

ISSCA Board of Directors

Track Guidelines

Impala owners have always been meticulous in taking care of their cars, however ISSCA would like to remind you of a few minimum checks while preparing for the events!


Fuel – There are several fuel stations located near the venues. Before you fire up the morning of the events, make sure you check your oil, coolant/water and brake fluid levels. There are also a few local speed shops and repair facilities in town in case you need a last minute item.


We recommend 32 – 36 psi. Check them in the morning during the fluid checks and set tire pressures while they are cold.

Mandatory Safety Rules

The goal is to maximize your driving time with the focus being on safety and a quality experience for everyone.

  • Helmets must be worn on the road course, drag strip, and while auto crossing at all times. Helmets must be Snell 2015 or 2020.
  • Seat belts must be worn at all times: while competing and while driving around.
  • No passengers other than the Auto Cross and slower Bracket Racing Classes will be allowed.
  • Remember long pants and closed-toe shoes are required at all driving events.
  • For those who have manual trans-equipped vehicles: In the event of a spin use both feet! (Full brake, full clutch)

Track-Specific Rules

Please check back for rules specific to this year’s track(s).

ISSCA Car Show

Car show rules were updated for 2016 and will carry over until further notice. Click the links below to view PDFs, or right-click and select “Save As” to download them.

Complete Rules
50 cars or fewer
51 – 100 cars
101+ cars

ISSCA Drag Racing, Auto Cross & Road Rally Solo 1

ISSCA SOP (As amended for 2012 Nationals)
CHAPTER Eight – Article Xl Sec. 2.

If any ISSCA rule conflicts with a track/facility rule, the track/facility rule takes precedence. Track/facility rules may change without notice posted here.


Car and driver must comply with the local track safety rules. Many drag racing facilities require car and driver to comply with IHRA or NHRA safety rules. It is the drivers responsibility to know and comply with these safety rules.


  • Late entries will not be allowed missed time runs.
  • Your ISSCA member number is your car competition number.
  • Any sized front and rear tire is allowed.
  • Fuel must be gasoline. No alcohol fuel allowed.
  • There is no minimum weight restriction.
  • Windows must be installed.
  • Big blocks and other motor swaps are allowed.
  • Any transmission may be used.
  • Any drive train is allowed.
  • Exhaust system must meet the requirements of the local track. (some tracks do not allow open headers and some actually have a maximum sound pressure level rule.)
  • All body panels must be factory original steel (or equivalent), except hood and bumpers (unless model year was available with aluminum panels from the factory).
  • Hood, bumper covers, and trim can be made of any material and of any aftermarket shape or style.
  • Suspension modifications are unrestricted.
  • Windows will be rolled down during runs. Air Conditioning cannot be turned on in the staging lanes or during a run.

Racing Rules


This class is ET bracket racing for all cars. There are no sub-classes.

Super Sport class is foot brake only…. no starting line aids or electronic ET aids, no trans brakes.


This is a heads up, Pro Tree class for naturally aspirated cars.


This is a heads-up, Pro Tree class for power adder cars (supercharger, turbocharger, nitrous).

Note: Drag racing is essentially bracket or “run what you brung.” Based on this all years can compete together in their appropriate bracket (dial in) or Super Natural or Super Pro category.

Autocross / Road Rally Solo 1

Note, these rules may be modified based on track safety requirements.

  • All competitors, crew, and guests must sign the waiver.
  • No alcoholic beverages or illegal drugs will be tolerated.
  • Snell SA 2015 or 2020 approved helmets are required as of 2022.
  • Mufflers are required.
  • Speed limit on site (off the track) is 10 MPH or as stated by the facility.
  • Running numbers will be your member number or otherwise assigned at registration.
  • Your car must be in safe running condition.
  • You must have working OEM seat belts or better.
  • All tires must have visible tread over the full diameter.
  • Street tires must run at OEM recommended pressures or higher.
  • Batteries must have the positive post insulated by either tape or padding.
  • All loose items must be removed from the car including floor mats.
  • Spare tire must be removed or securely fastened in place.
  • Event will be run rain or shine.
  • Entrants will be required to work the course at some time during the event unless otherwise stated.
  • There will be a two second penalty for each displaced pylon.
  • All drivers will attend a driver meeting and school if required.
  • All entrants will be tech inspected either by track personnel or by ISSCA staff.
  • Classification will be verified at time of inspection or registration.
  • Windows will be rolled down during runs. A/C will be turned off.
  • Hot-dogging, showing off or unsafe practice will earn a DNF.
  • Passengers will be allowed with proper helmet and seatbelt/harness if track rules permit.

Note: Two wheels off track will constitute a DNF. Off the track twice will be the end of your day!


Determined by the Point Assessment Schedule below.

Determine your class by adding all of the modifications outlined in the Modifications Points List.

New provisional class beginning in 2021: Extreme Modified

The purpose of the Extreme Modified class is to separate “race cars” and highly modified street cars. This proposal will group similarly prepared cars for BOI points distribution. The Extreme Modified class will only be used for the Autocross and Road Course events. Drag Race and Car Show classing we remain unchanged.

  • Vehicle must be licensed and insured, as well as fully “street legal” (working lights, etc.).
  • Interior and exterior must have a “finished” look
  • Exposed metal interior surfaces must be covered, painted, and/or coated. (No “race car” interiors, please.)
  • Any wheels are allowed
  • DOT tires with a UTQG Treadwear Grade of 200 or higher are permitted.

Any car with 18+ points will qualify for Extreme Modified, assuming they meet the listed allowances.  Cars not meeting these allowances will be placed into the Race class as defined.

Point Assessment Schedule

0 – 2Stock
3 – 7Prepared
8 – 17Modified
18+Extreme Modified
or Race

DIVISIONS will follow the above class breakdowns, and will be designated as:

1958 – 1964Division 1
1965 – 1990Division 2
1991 – 1996Division 3
2000 – presentDivision 4



Specialty compound tires3
Suspension bushing replacement, excluding sway bars & shock absorbers1
Sway bar revision: Front = 1; Rear = 11,1
Change of spring rate2
Brake conversion2
Conversion from drum to disk (front or back, each)3
Any rotor or drum of the same size as stock0
Brake cooling ducts0
Adjustable shocks3


Engine displacement change (per each 3% increase)1
Engine swap, except for exact replacement of original2
Removal of emission control device, per device1
Any air intake system change forward of the throttle body or above the carb1
Fuel injection or Carb revision on stock manifold2
Fuel injection or carb revision with non-stock manifold3
Camshaft change2
Valve size change and/or head modifications2
Ignition and/or computer module change (reprogrammed)2
Exhaust manifold change1
Exhaust system enhancements (cat back upgrade, larger diameter, etc.)1
Turbocharger or supercharger addition4
Intercooler addition4


Final gear ratio change less than 20% from stock2
Final gear ratio change more than 20% from stock3
Replacement of seats with racing seats as defined by the manufacturer1
Battery relocation to trunk1
Roll bars0
Nitrous Oxide bottle must be removed⚠️



  • Only standard production DOT tires (or available replicas) are allowed.
  • “Special construction” or “Special compound” tires are not allowed.
  • Tires can be of any size as fitted on stock size rims.
  • For 1958 to 1964, wheels can be up to 2” wider than stock.
  • For 1965 to 1990, wheels can be 1” wider than stock.


  • Only DOT labeled tires are allowed, including “special construction” or “special compound” tires.
  • These tires shall be 200 wear rating minimum.

MODIFIED: Any DOT labeled tire and any wheel is allowed.

EXTREME MODIFIED: Any wheels are allowed. DOT tires with a UTQG Treadwear Grade of 200 or higher are permitted.

RACE: Any tire and wheel is allowed.

BOI: Best of ISSCA

The system for scoring BOI at the ISSCA Nationals is designed, as much as possible, to allot equal points to all events in the competition.

** Note there are several changes/enhancements to the BOI point calculations that will better reward overall excellence. The changes are also intended to close in a few grey areas, minimize the possibility of a tie, reward the competitor for high performance, and add backup and tie breaker provisions.

The events to be included in BOI are:

  • Car Show
  • Sound-Off
  • Road Course
  • Autocross
  • Drag Racing

The ISSCA competing car that amasses the greatest number of points as an aggregate in these events will be deemed to be the Best Of ISSCA (BOI) – total possible points is 204. It is not necessary to enter all events to participate, but is unlikely that missing an event will allow a win. There will not be any places that will be awarded other than first place.

The points available to BOI entries will be based on performance and/or placement in each of the events. The placement will be among all entries in each event (i.e. a third place will be awarded third place points no matter how many of the entries finishing above are competing in BOI).

In each event, an entry will be awarded points as follows:

  • Car Show — Twenty (20) points for a completed judging sheet PLUS additional points based on placement (i.e. twenty (20) points for first place, nineteen (19) points for second place, eighteen (18) points for third place, etc. to a maximum of 20 places). Therefore, the first place entry will total forty (40) points, second will be thirty-nine (39) and so on to twentieth place which will be twenty-one (21) points. You must score a minimum of 100 points on the judging sheets to be eligible for a class position and points beyond the base 20.
  • Sound-Off — Twenty (20) points will be awarded for demonstrating a working system. Plus, additional points based on placement per class. There will be three classes for sound off. Maximum points for winning your class is 20 additional points. For both 1-600W and 601+ W classes, the competition will comprise of SPL measurements. Finishing positions will be in order of SPL measurement. Points will be awarded as 20 for the winner (40 total), 19(39 total) for second, 18 for third, and so on with a minimum of 20 points awarded for any vehicle competing.
    ** For stock class, we are still working on a method to allow stock head unit cars to equitably compete in BOI.
  • Road Course — Maximum possible points available for the Road Race is 40. The winner of each of the 4 classes will be awarded 40 points. Points for all other positions will be calculated comparing each competitor’s time in a given class to the class winner. There will be a minimum of 20 points awarded for each entry that successfully completes at least one lap without a DNF or black flag. The formula is:
Road Racing Points Calculation
  • Autocross — Maximum possible points available for Autocross is 40. The winner of each of the 4 classes will be awarded 40 points. Points for all other places will be calculated comparing each competitor’s time in a given class to the class winner. There will be a minimum of 20 points awarded for each entry that successfully completes at least one lap without a DNF or black flag. The formula is:
Auto Cross Points Calculation

Road Course and Autocross points example:

  • Driver C runs 42.429 seconds in his class. The winner of his class runs a 41.916 seconds.
    • 41.916 / 42.429 = 0.98791
    • 0.981725^3 = 0.9641644
    • 40 x 0.9641644 = 38.566 points toward BOI and a third-place finish
  • Drivers I and R will receive 20 points toward BOI and not the calculated values below 20.
  • Drag Race –- The scoring for BOI points will be conducted only for the Bracket racing – other classes like super pro and super natural do not count towards BOI points. All entrants who take the green in the first round (win or lose) will receive 20 points. Failure to do so will result in a DNF and 0 points for the event.  The winner of the event will receive 20 additional points for an event total of 40 points. Second place will receive 19 points for an event total of 39 points. The semifinal round losers’ round data will be analyzed to determine who was closest to their dial-in without breaking out; the entrant with the smallest margin of error will be awarded third place points. The other semifinal round loser will be awarded fourth place points. Thereafter, we will analyze the losers’ time/dial-in to determine placing and BOI points. Points for each position will be decrement by 1 from 40 down to 20.
    • Backup rule 1: in the event we don’t have per round data available from the track, round tiebreaker points will be awarded based on the initial qualifying bracket.
    • Backup rule 2: in the event that the initial bracket is lost as well, points will be awarded at MAX points available for all losers of that specific round.
  • BOI Bonus points — Bonus points can now be earned towards BOI total. If you win two (2) events you earn one (1) bonus BOI point.  If you win three (3) events you earn two (2) bonus BOI points, and so on, with a max possible of four (4) bonus points.
  • Tie Breaker Rules — In the extremely unlikely event that 2 participants are tied in overall BOI points, then the following tie breaker rules will apply:
    • 1: cumulative points for AX, RR, and DR.
    • 2: the best overall reaction time during the drag racing.
    • 3: if after all this there is still a tie, BOI is awarded as a tie.

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