1998 Rules

1998 Rules & Regulations

Basic Rules

Competitors may use the CD or cassette of their choice.
Adjustments to the sound system may be made during competition.
The program material must be reproduced using loudspeakers. Compressed air, explosive devices, etc. are expressly forbidden.
The contestant’s vehicle may be running as long as the following conditions apply:
1. Operation of the vehicle or sound system must not endanger the judge, competitor, or spectators.
2. The vehicle’s parking brake must be set.
3. The wheels must be chocked.
4. The hood must be closed.
5. The maximum idle speed must not exceed 2000 RPM.
6. A remote “kill switch” must be easily accessible from outside the vehicle for those competitors that are bolting (clamping, strapping, etc.) the doors of the vehicle closed during competition.
The contestant must be outside of the vehicle during judging and all doors, windows, and other openings to the vehicle must remain closed during this time.
Exception - Competitors may remain inside of the vehicle during competition provided:
1. They wear adequate hearing protection at all times. Removal of the hearing protection while inside of the vehicle will result in immediate disqualification.
2. The competitor’s maximum SPL never exceeds 140 dB. A measured SPL in excess of 140 dB will result in immediate disqualification.
After the judging starts, the contestants have 30 seconds to achieve their highest Sound Pressure Level (SPL).
Contestants may not open their vehicle during this time. If a contestant opens his or her vehicle during judging, their score will be disqualified at the sole discretion of the head judge.

Vehicle and Installation Guidelines

The passenger compartment and listening / measurement compartment shall be one and the same. (Intent: Measurements should be taken inside the passenger compartment.)
The passenger compartment must accommodate 2 average size adult passengers, sitting side by side, in a traditional seating arrangement. (Intent: The passenger compartment of the vehicle should approximate that of a typical vehicle.)
Additional Guidelines:
1. Competitor’s may remove their seats from the vehicle if they desire.
The windshield and front doors to the vehicle must function as an unobstructed boundary to the passenger compartment. (Intent: The listening environment should approximate that found in a typical vehicle, where the doors and the windshield act as “walls” to the listening environment.)
The windshield and/or windows to the vehicle may be replaced with another material as long as that material approximates the size, location, and function of the original equipment. (i.e. Plexiglas, bullet-proof glass, or another fully transparent material.)
Additional Guidelines:
1. The “slant” of the replacing material must approximate that of the OEM glass.
2. A maximum of 3 vertical braces may be used on the front windshield. The maximum width of each brace shall not exceed 2 inches. (Vehicles that participated in the 1997 IASCA or USAC Finals may be "granfathered" at the sole discretion of the dBDRA.)
3. Window tint shall not be permitted on the windshield of the vehicle. (Exception: A horizontal strip along the top of the windshield is permitted.)
4. The transparent area of the replacement material must be equal to at least 80% of the surface area of the OEM glass. (Vehicles that participated in the 1997 IASCA or USAC Finals may be "granfathered" at the sole discretion of the dBDRA.)
5. A secondary windshield and/or windows may be used in conjunction with the OEM glass as long as the maximum distance separating the two materials does not exceed ¼ inch.
No partitions or other barriers may divide or compartmentalize the passenger compartment. This includes foot-well panels. (Intent: The listening environment should approximate that found in a typical vehicle.)
Nothing must interfere with placement of the microphone jig.
All reflective surfaces, with the exception of the windshield and dashboard, must be located a minimum of 1 microphone jig length (13 inches) from the microphone capsule. (Intent: Reflective surfaces shall not interfere with the measurement equipment.
Sound producing devices must not interfere with the measurement equipment. This includes, but is not limited to; horns, waveguides, vents, or other devices that are deliberately placed in close proximity to the microphone capsule. (Intent: Nothing shall interfere with the measurement equipment.)
All loudspeaker enclosure, and/or baffle boards, with the exception of those mounted in the kick-panels or doors, shall be located behind an imaginary plane that stretches from the trailing edge of the driver’s door to the trailing edge of the passenger door.
Additional Guidelines:
Compliance with this rule may be verified by using the following test: Two judges position themselves on opposite sides of the vehicle. A string (or wire) is passed through the open doors of the vehicle. Both judges pull the string so that it is taught. Next, the judges move the string in unison so that the string slides along the trailing edge of each judge’s respective door jamb. If the string does not touch the enclosure (or loudspeakers), then the test passes.

Additional Rules for Competition at Regional, National, and Global Level Events

The following rules shall apply to all Regional, National, and Global Level events. The enforcement of these rules at the Local Level is at the discretion of the show promoter.

The Official dB Drag Racing CD (dB Jams Volume 1) must be used as the program material.
Power Classes

Amateur Power Classes:

0-5000 Watts
5001-10,000 Watts
10,001-50,000 Watts

Pro Power Classes:

0-5000 Watts
5001-10,000 Watts
10,001-50,000 Watts

Optional Extreme Power Class (includes competitors that meet any of the following criteria):

Commercial vehicles
Manufacturer’s vehicles
Vehicles with more than 50,000 Watts of power
Vehicles with homemade or non-commercial amplifiers or speakers. This also applies to equipment that was not originally designed for operation in a 12-volt automotive environment.

Rules Q & A

Can I use the same vehicle to compete in more than one dB Drag Racing power class at the same event?

No. Each vehicle may compete in one, and only one, power class at each event.

Can I modify the size of my doors?

No. The size and location of the doors must not be altered.

Do the windows in the doors need to be capable of rolling up and down?

No.

How many doors does the vehicle need to have?

As a minimum, the vehicle must have 2 doors. One for the driver and one for the passenger. Each of these doors must be located in the traditional locations for the driver and passenger. (i.e. Opposite sides of the vehicle.) Exception: Vehicles that were originally manufactured with only one door. (i.e. Mail delivery jeep.)

Can I pull a trailer full of batteries?

No. The sound system, electrical system, batteries, etc. must all reside inside the vehicle proper.

Can I use a generator to help power my system?

No. (It is okay to use a generator to recharge your batteries between rounds, however.)

Does the vehicle need to have an operational engine?

Yes. For clarification purposes, the engine is the motor that is used to propel the vehicle.

Does the engine need to provide power to the vehicle’s electrical system?

Yes. The vehicle’s engine must be the sole source of power to the vehicle’s electrical system and batteries.

Does the sound system need to be powered by the vehicle’s electrical system?

Yes.

What is the maximum voltage of the vehicle’s electrical system?

18 volts maximum – no load – at full output.

Can the size (air volume) of the passenger compartment change during competition?

No. For example: The subwoofer enclosure can not move forward. Etc., etc.

Can I pressurize the cabin of the vehicle?

No.

Can I use a signal generator instead of a cassette or CD?

No. The program material being played must originate from a conventional source unit.