This class has it all, as supercharged, nitrous and turbocharged cars all compete in this action-packed legal weight class!


Purse for this class is $10,000/event and broken down as follows:

Winner: $5,000

Runner Up: $1,500

Semi: $750

Quarter: $500

DESIGNATION: PM or Pro Modified followed by car number. Numbers must be at least 4” tall and on both side windows, upper left of rear window and upper right of windshield.

FIELD: 16 car qualified field.

MINIMUM WEIGHT: 2475 pounds for Nitrous entries, 2600 pounds for Supercharged entries and 2650 pounds for Turbocharged entries.

MAXIMUM CUBIC INCH ENGINE DISPLACEMENT: 526 cubic inch maximum for Supercharged cars, 540 cubic inch maximum for Turbocharged  entries and unlimited cubic inches for Nitrous powered entries. All rules subject to change at the sole discretion of the X-DRL Technical Services Department.


BODY APPEARANCE: All vehicles must be professionally finished, painted, lettered, numbered and decaled.

BODY: Funny car or one piece bodies not allowed even if equipped with doors. Maximum front end overhang of 45” as measured from centerline of front spindles. An X-DRL accepted extension may be used to create 45” overhang if the front end overhang of the original body is less than 45”. All bodies must originate from a documented production vehicle. All new cars must be accepted by the X-DRL Technical Services Department prior to construction.

DOORS: Required. Doors must be functional and able to be opened from both the inside and outside of the vehicle. Doors may be fabricated from carbon fiber, fiberglass or metal. A metal deflector between the fenders and the leading edge of the doors is required.

FIREWALL: All firewalls must be made of steel or titanium (.024 minimum thickness). Magnesium, aluminum or composite not allowed.

FLOORS: Replacing stock floors with .024″ steel, .032″ aluminum allowed. Driver’s side floor pan must be .024″ steel and must extend from firewall to rear of drivers seat and be welded in.

HOOD SCOOP: Allowed. Must be finished and painted to follow the bodies paint scheme.

TAIL LIGHT: Functional rear tail light is required. Minimum of 1 tail light is required to be operational and controlled from the drivers compartment.

WHEEL WELLS: Rear wheel wells must be separate for each of 4 tires. Maximum height of rear wheel tubs from ground is 40 “.

WINDOWS AND WINDSHIELD: Required. May be replaced with .125 minimum polycarbonate material, such as Lexan MR 4000 or equivalent required. An opening with a 4″ diameter minimum is required on side windows adjacent to the driver.


BATTERY: Maximum of two batteries allowed. All batteries must be securely fastened using metal fasteners. Batteries  (including battery box) must weigh less than 100 lbs. Must have an external master mechanical electrical disconnect at the rear or vehicle marked “PUSH OFF”.

BALLAST: Permitted. Any ballast mounted on, or in front of, forward crossmember is limited to 60 pounds maximum, including bracket. Maximum length of bracket is 12 “, measured from the front of the crossmember. Maximum distance from front motor plate to front of bracket is 36 “. Bracket may be constructed of either minimum 1-1/4”  x .058” wall round chrome-moly tubing with minimum four (4) 3/8” diameter SAE Grade 8 bolts or welding for attachment, or of minimum ¼” 6061 T6 aluminum plate with minimum four (4) ½”  SAE Grade 8 bolts for attachment. Other designs for mounting weight forward of front crossmember must be X-DRL accepted prior to use. All other weight bars, pucks, etc. must use minimum 1/2-inch-diameter SAE Grade 8 bolts for attachment.

BRAKES: Four wheel brakes with dual master cylinder mounted above frame rails required. Application of brakes must be a function of the driver. Steel brake lines required and must be routed away from the flywheel and driveline area. One line-loc system with one activation source permitted on front wheels only.

CHASSIS: Must be SFI Spec. 25.1E or 25.2 with current NHRA certification tag prior to competition.

DRIVER LOCATION: Must be in conventional left hand drive location.

GROUND CLEARANCE: Minimum of 3” required from front of car to 12” behind front axle centerline, 2” minimum for remainder of car.

STEERING: Stock type steering in conventional location required. Disconnect meeting SFI Spec. 42.1  required with a minimum wheel diameter of 11”.

SUSPENSION: Race car type suspension required. Solid suspension prohibited. Shock absorbers required for all four wheels. Lockup shocks prohibited. Active suspension of any kind prohibited. Any ability to make on-track setting/rate changes based on “real time” data or input from any source is prohibited. Electrically or pneumatically controlled, hydraulic shocks and/or struts are permitted, provided all adjustment settings/changes are preset before the run. Only 1 three-wire shielded cable connection is permitted from the top of the shock/strut to the shock/strut controller. Electrical connections of any other kind to or from the shock/strut prohibited. Shock/strut travel sensors permitted, but may ONLY be connected to the vehicle data recorder. Shock/strut control boxes that have connections for travel sensors must have the pin removed from the connector. Connection to serial port on control box prohibited once car reaches the ready line. All wiring must be visible and easily traceable.

TIRES: Slicks permitted. Must be automotive type tires designed specifically for racing. Tires cannot be located outside of bodyline. All tires must have manufacturer, model and or part number and size information must be clearly and permanently designated on sidewall. Maximum height of front tire is 25”.

WHEEL BASE: Minimum 100″, Maximum 115″. S-10, Ranger, Dakota Maximum 125″. Full size trucks Maximum 140”. Maximum variation is 2” side to side.

WHEELIE BARS: Required, maximum 104” measured from rear end centerline to center of wheelie bar wheel. Nonmetallic wheels required.

WHEELS: Wheels meeting SFI Spec. 15.1 or 15.3 mandatory. Inner liners accepted.  Maximum rear wheel width 16” measured between the inner and outer tire mounting surfaces. Use of a liner mandatory on all non bead lock wheels.


CLUTCH/FLYWHEEL: Flywheel and clutch meeting SFI Spec. 1.3, 1.4, or 1.5 certification required. Three discs maximum with a maximum disc diameter of 11 “ or four discs maximum with a maximum disc diameter of 8 “. Flywheel shield meeting SFI Spec 6.2 or 6.3 required. Maximum depth of flywheel shield: 9.400 “. Clutch must be manually operated by driver’s foot: electronics, pneumatics, hydraulics, or any other device may in no way affect the clutch system. Throwout bearing must release all fingers, levers, stages, etc. simultaneously. Staged or variable release clutches of any description prohibited.

CYLINDER HEADS: Hemi, canted-valve, or wedge heads permitted. Billet heads permitted. Maximum one spark plug per cylinder. Maximum supercharged valve sizes: intake 2.400 “; exhaust 1.900 “.

ENGINE: Internal-combustion, reciprocating, single-camshaft, 90-degree V-8 automotive-type engine. Bore Spacing is set to a MAXIMUM of 5.300” for Nitrous Cars, 5.000” for turbo cars, 4.900” for Billet Hemi head supercharged vehicles and 5.000” for all other supercharged combinations.

DRIVELINE: A full 360 degree drive shaft tube is required over yoke, extended a minimum of 12” required from transmission tail shaft. Minimum thickness of tube housing is .050” chrome-moly or titanium. Two piece units accepted with a minimum of 6 attachment points using 3/8” grade 8 bolts. SFI Spec.  43.1 Driveshaft required.

ENGINE CONTAINMENT SYSTEM: SFI Spec.  7.1 lower engine containment system required. If a flexible 7.1 system is utilized, it must be supported by a belly pan made from carbon fiber or .032” aluminum with a minimum 2” verticle lip.

ENGINE SETBACK: Maximum of 10% of total vehicle wheel base as measured from the centerline of the forward front spindle to center of front spark plug hole.

EXHAUST: Open conventional style headers required. Exhaust gasses must be directed out of the body  and away from the driver and fuel system.

HARMONIC BALANCER: SFI Spec.  18.1 certification required.

FLYWHEEL SHIELD: SFI Spec. 6.2 or 6.3 certification required.

FUEL: Alcohol, gasoline and methanol allowed. The use of nitromethane and/or propylene oxide is strictly prohibited.

FUEL SYSTEM: Fuel cell must have pressure cap and be vented to outside of body. Fuel cell meeting SFI Spec 28.1 mounted in front of radiator permitted; must be mounted between framerails and enclosed in a round tube frame, minimum 1 ¼” O.D. x .065” chrome-moly tubing. Extra tank(s) prohibited. Artificial cooling or heating systems (i.e., cool cans, ice, Freon, etc.) prohibited. Circulating systems, not part of normal fuel-pump system, prohibited. Water injection permitted on Nitrous entries only, only water permitted in water injection system.

IGNITION: Maximum one magneto or distributor, maximum one spark plug per cylinder. Magneto systems are limited to a single 44-amp maximum output system. The use of MSD 8973 or MSD 7730 units are permitted on supercharged and turbocharged entries. The use of MSD 7531 unit is permitted on nitrous-assisted entries. Electronic starting line rpm limiters (two-steps) are permitted on all entries.

INDUCTION: Any induction system permitted on nitrous-assisted, supercharged and turbocharged entries. Electronic fuel injection must be closed, OEM-type system; i.e., may monitor only engine functions. Monitoring of vehicle performance criteria, wheel speed, driveshaft speed, vehicle acceleration, etc. by fuel-injection system prohibited.

INJECTOR SCOOP: Injector scoop may not extend more than 16 ” forward of the center of the forward engine cylinder, may not extend more than 10 “ behind the center of the rear engine cylinder. May be no more than 1 ½” above roofline.

INTAKE MANIFOLD: SFI Spec 23.1 or an X-DRL approved burst panel is required on all vehicles.

NITROUS OXIDE: Prohibited on Turbo and Supercharged entries. HOBB switch required. System must be activated by wide open throttle switch. Maximum of two bottles stamped with a DOT-1800 pound minimum rating.

OIL LINES: All pressurized flexible oil lines must pass a minimum 750 psi 30 second test and be tagged to indicate successful testing.

REAR END: Aftermarket axles with minimum 5/8-inch-diameter studs and axle-retention device mandatory. Full- floating or live axle units required. Maximum numeric rear-end gear ratio 4.57-to-1 for supercharged and turbocharged entries.

STARTER: Required. All entries must be self-starting. On board starter required. The use of remote-mounted battery packs permitted for starting purposes only. Remote battery may not be used for starting after the burnout has been started. No push starts allowed.

SUPERCHARGER: Screw-type supercharger prohibited. Hi-helix or standard helix Roots type supercharger only.  Manifold burst panel meeting SFI Spec 23.1 plus restraint system meeting SFI Spec 14.2, including injector restraint straps mandatory. Maximum supercharger overdrive limit is 14.55 percent on all combinations. Intercoolers, variable multi-speed supercharger devices prohibited. The top opening may not exceed 12 “ in length or 5 “ in width. The entire inlet opening must be on/in the upper surface only. The maximum length from the front of the supercharger drive pulley to the leading edge of the rotor is 15 “. Offset drive pulleys, spacers, modified cases, or attaching methods may not be used to add to the 15” maximum. The rotors must be driven from the front (both the external drive and the internal gearing. Any inlet/outlet cavity in front of the rotors is restricted to a maximum of 3.000 “ measuring from the face of the bearing plate to the front of the cavity. Roots Type: Maximum size: 14-71, 22 1/4-inch case length, 11- ¼” case width, 19” rotor length; maximum rotor diameter:5.840 “ including fixed stripping. The case must be one piece with removable front and rear bearing end plates; rotor must be contained within one-piece case. Roots-type high helix: Must adhere to same maximum case dimensions and maximum rotor cavity diameter as standard Roots. Rotor helix angle may not exceed 6.5 degrees per inch (123.5 degrees total over 19” maximum rotor length).

THROTTLE: Throttle control must be manually operated by driver’s foot. Electronics, pneumatics, or hydraulics is permitted for starting line/staging rpm limiters only.

TURBOCHARGER: Twin turbochargers limited to 88mm. All turbochargers must meet SFI Spec 61.1. Boost controller manufactured by Hyperactive Performance Solutions, part number PMBL mandatory. No other boost controller or form of boost control permitted. Must be installed per manufacturer’s instructions. Any modification or attempt to disable or defeat prohibited. Maximum boost may only be set by X-DRL Technical Services Department. Air-to-air or water-to-air intercoolers prohibited  on turbocharged all entries. Turbocharger size will be verified by measuring the housing bore at the leading edge of the impeller wheel. The maximum diameter of the housing bore at the leading edge of the wheel may not exceed 2mm more than the maximum allowable turbocharger size permitted.

TRANSMISSION: Aftermarket planetary, clutchless, or X-DRL accepted aftermarket automatic transmission permitted. All transmissions must be equipped with a one piece SFI. Spec 4.1 transmission shield. Supercharged entries limited to maximum of three forward speeds and reverse; all other entries limited to maximum of five forward speeds and reverse. When an aftermarket automatic transmission is utilized, an SFI Spec 6.3 flexplate shield and an SFI Spec 29.1 flexplate are required. Aftermarket converter drive units permitted. When an aftermarket converter drive is utilized, a 6.3 flywheel shield and an SFI Spec 29.1 flexplate are required (SFI Spec. 29.2 recommended). All entries utilizing a converter must be equipped with a neutral safety switch and a Reverse lock out. Transmission brake permitted on all converter equipped entries. Lockup converters and overdriveunits are prohibited. A 1-to-1 relationship is mandatory in high gear for all transmission types. Automated, electric,or pneumatic shifting devices permitted on all transmission types; must be controlled by preset engine rpm and/or time functions only.


CREDENTIALS: A valid X-DRL membership, X-DRL, NHRA, or IHRA Competition License is required to compete. Valid NHRA or IHRA competition licenses may be transferred when presented with a current physical.

COMPUTER / DATA ACQUISITION: Allowed, must be standalone and used for information gathering only.


TOW VEHICLES: Allowed. A valid driver’s license is required to operate any type of tow vehicle. All passengers must be seated inside of vehicle with all doors closed. Riding in open hatchback, trunk or cargo area not allowed. ATV’s are allowed with a maximum of one passenger who must be seated at all times. Golf carts are allowed with a maximum of three passengers who must be seated at all times. Posted pit speeds must be obeyed at all times. If pit speed is not posted, maximum pit speed will be 10 mph.


DRIVER RESTRAINT SYSTEM: SFI Spec.  16.1 certification required. 7 point system recommended

ENGINE CONTAINMENT SYSTEM: X-DRL accepted lower engine containment system required. The system must include the oil pump and related components and be a minimum of 3” above ground.

FIRE SYSTEM: SFI Spec.  17.1 system required. System must contain a minimum of 20 lbs of fluid or gas fire suppression agent. One nozzle required inside driver’s compartment must be directed at driver’s feet. Two or more nozzles must be directed at front of engine and fuel cell. All fire suppression must be released with a single actuation. (i.e. single handle, button or lever)

HEAD AND NECK RESTRAINT: SFI Spec. 38.1 required. An aluminum skid plate located above driver’s head is recommended.

HELMET: SN-2000 or newer of SFI Spec. 31.2 or 41.2 required. Use of open face helmet prohibited. EjectHelmet Removal System (Part # SDR 890-01-30) or equivalent recommended

MASTER ELECTRICAL CUTOFF: Required. Must be clearly labeled “PUSH OFF”.

PARACHUTES: Dual parachutes required. Separate shroud-line mounting points with 1/2” sleeved grade 8 bolts required.

PROTECTIVE CLOTHING: A driver’s suit meeting SFI Spec. 3.2A/15, gloves meeting SFI Spec.  3.3/15, shoes meeting SFI Spec. 3.3/15 required for Nitrous and Gasoline burning Turbocharged entries. A driver’s suit meeting SFI Spec. 3.2A/20, gloves meeting SFI 3.3/20, shoes meeting SFI Spec.  3.3/20 required for Supercharged and Methanol burning Turbocharged entries. A head sock meeting SFI Spec. 3.3 is required unless a helmet manufactured with a skirt meeting SFI Spec.  3.3 is used.

RF SHUTDOWN RECEIVER: Properly functioning Electrimotion shutoff device (PN: RF001PS or combination PN: SB001 and RF001) required.

ROLL BAR PADDING: SFI Spec. 45.1 required.

TRANSMISSION: All transmissions must be covered by a one piece SFI Spec. 4.1 restraint.

UPHOLSTERY: Driver’s seat foamed with energy absorbing material, formed for the driver and covered with flame retardant material is required. “Wrap Around” type seat or fiberglass/carbon fiber one-piece bucket accepted seat frame of chrome-moly tubing must be installed as a permanemt part of the chassis. Lateral Helmet supports required.

WINDOW NET: SFI Spec.27.1 required.