The quickest and fastest naturally-aspirated passenger cars, and some of the closest side-by-side drag racing you will ever see!


Purse for this class is $17,000/event and broken down as follows:

Winner: $6,000

Runner Up: $2,000

Semi: $1,000

Quarter: $750

Qualifier: $500


DESIGNATION: XPS or Xtreme Pro Stock followed by the car number. Numbers must be a 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: 2425 LBS with driver at completion of run.


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

BELLY PAN: Required. Must extend beyond leading edge of engine and accessories to the midplate and incorporate a 2 “ minimum lip on the edge of all units.

BODY: Must be 2003 or later model year factory produced 2 door coupes and sedans. Sports cars, sedan deliveries and trucks prohibited. Original OEM body shell or X-DRL accepted composite replacement required. Chopping, channeling, sectioning, or other alterations to contour, length or width are prohibited. All composite replacement parts must be X-DRL accepted and exact duplicates of OEM components and may not be modified.  The front end may be lengthened in the cowl area to facilitate body relocation and wheelbase modifications. The maximum front-end overhang on all entries is 45 “.

BUMPERS: Stock or composite duplicates required front and rear, may be molded into body. Must be original size and shape.

DOORS: Must be functional from inside and outside.  Exact duplicates in fiberglass or carbon fiber permitted. All entries must incorporate a metal deflector between the fenders and the leading edge of the doors.

FIREWALL: Moving stock firewall rearward for engine installation permitted. Replacing stock unit with one of .024” steel or .032” aluminum allowed; Magnesium prohibited.

FLOOR: Replacing stock floors with .024” steel or .032” aluminum allowed.  Replaced floors must be stock in appearance and location.  Driver’s side floor pan must be minimum .024” steel and must extend from firewall to rear of driver’s seat and must be welded in place. Chassis, frame and driveline must be below floor.  Rear floor may not be higher than 8” above door sill. Belly pan mandatory between the center frame rails extending from the rear to the front cross member or to the bell housing.  All pans must be designed to facilitate fluid retention.

GRILLE: Must retain OEM appearance as visible from front. May have covering over back of grille to prevent air passage. Any factory accessory package must be accepted by X-DRL, i.e., spoilers, air dams etc…

HOOD & HOOD SCOOP: One opening only.  The highest point of the hood scoop may not exceed 15” in overall height above the original hood surface, measured from the leading edge of the scoop. Must be finished and painted to follow body paint scheme. Hood must be stock size with no bubbles.  Cowl section may be molded to hood.  A minimum of four fasteners must be used on the leading edge of all lift-off hoods.  Sensors, lines, or wires, etc. are prohibited from being in hood scoop.

STREET EQUIPMENT: Complete stock seal beam head light lenses or accepted replica and stock tail light lenses in original factory location required.  Any other street equipment which does not affect external appearance may be removed. Side marker lights optional.  Minimum 1 tail light required to be operational and controlled from the driver’s compartment.

SPOILERS: Rear spoilers must measure between 14” to 17”, measured from the body line at spoiler transition point to the tip and may have no less than 0 degrees from horizontal.  May not be molded into deck lid.  All spoilers to be painted to match paint scheme.  Rear of chute pack cannot be forward of rear tip of spoiler.  Roof-mounted spoilers prohibited.  Air foils prohibited.  Any front spoiler used must have been factory available for body used.  Spoiler outside of deck lid opening may not exceed 8” wide. Spill plates may be not more than 6” high and 26” long. Spill plate may not be molded to the quarter panel.  A straight edge will be placed on the spoiler, perpendicular to the centerline of the car and level to the ground.  Distance between level and lowest part of spoiler can be no more than 2”. A wickerbill must be attached across the entire trailing edge of the spoiler.  It must be constructed and attached in a way that will prevent air from passing under or through the unit.  It must be 90 degrees from the top of horizontal plane and a minimum of ¼” tall from spoiler surface and a maximum of ¾” tall from spoiler surface.

WHEEL WELLS: Rear, must be 4 independent wheel wells, 1 for each tire.

WINDSHIELD, WINDOWS: Full windows required, .125” minimum polycarbonate materials, such as Lexan MR 4000 or equivalent required. Must match original contour and shape, and mount in stock location.  No bubbles in side windows for tire clearance. Windows must be closed, need not be operative.  Cutting and/or notching windshield permitted if covered by hood scoop.


BATTERY: Maximum 2 batteries.  Must be securely fastened using metal fasteners. Must have external master mechanical electrical disconnect at rear of vehicle marked “push-off”.

BALLAST: 250 LBS maximum.  Shot bags must be contained in weight box. Ballast attached on or in front of the forward cross member is limited to 60 lbs. maximum, including bracket.  Any bracket may not exceed 12” in length that is attached by bolting, measured from the cross member, attached with a minimum of (4) ½” bolts.  The maximum distance from the front of any weight ballast bracket to the front of the motorplate is 36”. Any car found with unsecured or illegal ballast following a run will have the run disqualified and possible disqualification from the event at discretion of Technical Department.

BRAKES: Four wheel brakes mandatory with dual master cylinder mounted above frame rails on all entries.  Steel brake lines mandatory.

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

DRIVER: Must be in stock conventional left hand drive location.  Driver’s seat to be no less than 24” from center of rear axle to seat back measured where shoulder harness passes through.

ENGINE SETBACK: Maximum setback is 80.125” as measured from the center of the rear axle to the back of the engine blocks bell housing mounting surface. Modifications to the block or bell housing mounting surface to gain additional setback are prohibited.

FUEL SYSTEM: One SFI Spec. 28.1 fuel cell mandatory, with pressure cap be vented outside of body.  Trunk mounted fuel system prohibited.  All fuel cells must be mounted in front of engine between frame rails and protected by a minimum of 1-1/4” x .065 chrome-moly tubing. Fuel cell must be grounded between filler ring and chassis.

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

RADIATOR: Full size automotive radiator located in front of engine with one water pump mandatory.  Remote mounted water pump permitted between engine and radiator.

STEERING: Stock-type steering in conventional location required. Minimum steering wheel outside diameter is 12”. Disconnect meeting SFI Spec. 42.1 required.

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. The use of positive suspension stops to control ride height during a run prohibited.

WHEELS/TIRES: Slicks permitted.  Must be automotive type designed for racing.  All tires must have manufacturer, model and or part number and size information clearly and permanently designated on sidewall.  Clearance from outside of front tire to inside of fender at widest point not to exceed 4”.  Rear clearance 3” from outside of tire to inset of fender at widest point.  Inner liners accepted. SFI Spec. 15.1 bead-lock rear wheels required.  Maximum rear wheel width 16” measured between the inner and outer tire mounting surfaces.

WHEEL BASE: Minimum 100”, Maximum 105”. Maximum variation is 1” side to side.

WHEELIE BARS: Required. Wheels on wheelie bars must be non-metallic.  Maximum length of wheelie bar 80” from center of rear axle housing to center of wheelie bar wheel. 


CLUTCH: SFI Spec. 1.1 or 1.2.  Clutch release and bearing engagement/disengagement must be manually operated by driver’s foot.  The use of electronics, pneumatics, hydraulics or any other device is prohibited from affecting clutch operation.  Lock up or multi-stage units prohibited.  All levers in the clutch assembly must be attached to the pressure ring.  Any diameter 2-disc clutch or minimum 7.5 “, maximum 8 “ 3-disc clutch assembly may be used in SFI Spec 6.1 or 6.3 bell housing.  Measurement is obtained from clutch disc outside diameter.

DRIVELINE: Full 360 degree drive shaft tube required over yoke, extended from transmission tail shaft. Minimum length of 12 “ required from transmission tail shaft.  Minimum thickness of tube housing is .050” chrome-moly or titanium.  Two piece accepted with minimum of 6 points using 3/8” grade 8 bolts and nuts to join upper and lower half.

FLYWHEEL SHIELD: SFI Spec. 6.1 or 6.3 with current certification.  See SFI Spec 6.1 or 6.3 for motorplate requirements. www.sfifoundation.com

REAR END: Automotive type required.  After market axles required with 5/8” stud bolts and axle retention device.  Welded spider gear prohibited.  Full floating or live axle assembly is optional.

TRANSMISSION: Planetary type transmission required.  All entries must utilize a one piece transmission shield meting SFI Spec 4.1.  Automated shifters and electronic timed shifters are prohibited.  Multi-functional single button shifters prohibited.  If a pneumatic shifter is used, each shift must be activated by its own individual control button.  Routing of pneumatic shifter lines must be X-DRL accepted prior to competition.  All pneumatic shifter lines act independently and not a result of or activate other air systems.  Torque convertor equipped automatic transmissions allowed.  SFI Spec 6.3 bellhousing and SFI Spec 29.2 flexplate required on all torque converter equipped entries.


CARBURETION: Limited to any two 4-bbl.  American automotive carburetors available to the general public with any internal modifications. Carburetors may be split.

ELECTRONIC FUEL INJECTION: Allowed.  Maximum 16 injectors placed in any location above the cylinder head.  Controller must operate in “Open Loop” configuration with no connection to O2 sensor or EGT sensor.  Controller Manufacturer, Model, Software and Firmware must be approved for use by X-DRL before use in competition.

EFI Controller is stand alone “Fuel Only” with rpm signal provided from crank and or distributor trigger separate from the ignition trigger.  EFI Controller can have output to data logger only.  EFI Controller must be commercially available before use in competition.  Wiring harness cannot contain provisions for oxygen sensors, must have specific Part Number approved by the Technical Services Department. EFI Controller can only “send” data to data logger not receive.  EFI Controller may not monitor any performance criteria of the vehicle: i.e., wheel speed, drive shaft, acceleration, track position, etc.  The only sensors to be utilized and or monitored with the EFI controller are as follows:  TPS (Throttle Position Sensor), MAP (Manifold Air Pressure), IAT (Inlet Air Temp.), Fuel Pressure, and Coolant Temp.

May utilize either 2-4 blade or 4-2 blade throttle bodies, must be installed with throttle blades in a horizontal location.  No forward facing throttle bodies.  Throttle bodies must be production units commercially available to all competitors.  Intake manifold must be of conventional design with no active components, i.e., runners.  Inlet air must be drawn from a single opening forward facing hood scoop of conventional design.  New non-conventional hood scoops may be submitted for approval but must be approved by X-DRL Technical Services Department before use in competition.

EFI and Carburation cannot be combined on an intake manifold.

If an evident competition advantage exists, rules may be adjusted to compensate by the X-DRL Technical Services Department.

CYLINDER HEADS: Cylinder heads must be configured after OEM or X-DRL accepted configuration, must contain OEM or aftermarket factory casting number and logo, and must be available to the general public.  Heads must be cast aluminum.  No billet materials, magnesium or other materials allowed.  Maximum 2 valves and one spark plug per cylinder. New Cylinder Head configurations, designs, processes and or materials may be submitted to X-DRL Technical Services Department for review and possible approvals.

ENGINE: Internal combustion, reciprocating, naturally aspirated, single camshaft, 90 degree V-8 automotive-type mandatory. Crankshaft centerline must intersect cylinder bore centerlines and be symmetrical.  Limited to 830ci hemi and 840 ci on wedge entries, without tolerance.  Blocks may be aluminum or cast iron. No magnesium or other materials allowed.  One distributor maximum.  Bore Space Maximum 5.000”.  Serial number assigned by the engine builder must be clearly and permanently marked externally and clearly accessible on the Block and Cylinder Heads.  All moving engine components must be accepted prior to utilization.  Additionally, the use of beryllium, carbon fiber/kevlar, ceramic, or composites are prohibited from use on these components.  The rod and main bearing assemblies must be of conventional sleeve design.

OIL LINES: All oil pressure lines must pass a minimum pressure test and be clearly labeled as passing the testing process.

EXHAUST SYSTEM: Open conventional style headers mandatory.  Side exit exhaust systems prohibited.

FUEL: All entries must utilize VP Racing’s Q16 or C23 Fuels.  The use of propylene oxide, nitrous oxide, methanol, nitromethane, or any other additive is prohibited. Any modification of fuel chemistry or use of additives will result in disqualification

IGNITION: Digital ignition Systems of the following part numbers are approved for use: MSD 7730/7720, 7530, 7530T, and 75301, all external wires that have the ability to activate retard functions must be clearly disconnected. (ex. MSD 7530, 7530T and 75301 (pink, tan, violet and white wires), MSD 7730/7720 (pink, violet, tan, light green and green). MSD 7730 power grid system allowed provided the MSD 7720 (Ignition Module), MSD 7740 (4 connector CAN-Bus Hub) and/or MSD 7751 (Launch Control Module) are the only products used to complete the ignition system.   Any electronic traction control and or slew device, internal or external is prohibited.


DATA/ELECTRONICS ACQUISITION: Allowed for the monitoring and recording of data 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.  Posted pit speeds must be obeyed at all times. If pit speed is not posted, maximum pit speed will be 10mph.


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

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

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

FIRE SYSTEM: SFI Spec 17.1 system required.  System must contain a minimum of 5 lbs. 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.

HEAD AND NECK RESTRAINT: SFI Spec 38.1 required.

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

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

PARACHUTES: Dual parachutes required.  Separate shroud-line mounting points with ½” sleeved grade 8 bolts required.

PROTECTIVE CLOTHING: A driver’s suit meeting SFI Spec. 3.2A/15, gloves meeting SFI Spec. 3.3/5 and shoes meeting SFI Spec. 3.3/5.

RF SHUTDOWN RECEIVER: Properly functioning Electrimotion shutoff device (PN: RF001PS) required.

ROLL BAR PADDING: SFI Spec. 45.1 required.

UPHOLSTERY: All seats must have minimum 24 “ high seat backs.  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 permanent part of the chassis.  Lateral helmet supports required. Dash board exterior appearance must be retained: replicas of original allowed.  Head liner optional: area must be painted if headliner is not used.

WINDOW NET: SFI Spec. 27.1 REQUIRED. All rules subject to change at the sole discretion of the X-DRL Technical Services Department.