Rules: Pro Modified


Updated May 01, 2020, 2021 Update Coming Soon…


Car, driver, and up to four crew:   $350.00.
Additional crew members:  Track Crew pricing. Additional camping fees may be charged for additional camping units. Additional camping units may not be able to park with your race unit.
Please Note:  DoorWarz entry fees are handled by the organizers of the event.  Event entry will be announced when set by the tracks.

$200 annual membership.

Purse will be discounted the amount of Membership fee if unpaid before the end of the first race of the series.  

West Coast Pro Modified Rules

Pro Mod is designed for production vehicles and is the quickest and fastest door class. Entries have the option to run either a small block or big block engine combination. All entries are permitted the use of dual power adders.  All engine combinations are allowed to use gasoline or methanol fuel.  These Rules have been set to be liberal intentionally to allow all Pro Mod race cars to participate.
Note: This set of class rules is presented to all competitors under the assumption that any modifications not specifically written within these rules shall be deemed illegal, unless the competitor has the expressed written consent from the WCPM Director.

This class will be run on a min 8 car qualified heads-up field, NHRA Pro Style Ladder on a .400 Pro Tree.

Minimum Weights:

CombinationCubic InchNotesWeight
Naturally AspiratedUnlimited No Min.
NitrousUp to 865 2200
866-910 2300
911-960 2350
Roots SuperchargedSmall BlockUnlimited OD2200
Big Block Up to 460Unlimited OD2400
Big Block 461-526Unlimited OD2500
Screw BlowersSmall Block Up to 485C – Rotor Unlimited OD2450
Big Block Up to 526C – Rotor 92% OD2600
Big Block Up to 526C-Rotor Unlimited OD2700
Big Block Up to 526D Rotor up to 108% OD2600
Centrifugal SuperchargedSmall Block140mm max2300
Big Block Up to 526140mm max2500
Big Block Up to 565140mm max2550
Turbo on MethanolSmall BlockSingle 118mm2200
Small BlockTwin 88mm2350
Small BlockTwin 94mm2425
Big Block Up to 526Single 118mm2400
Big Block Up to 526Twin 88mm Wedge head2650
Big Block Up to 526Twin 88mm Hemi head2650
Big Block Up to 526Twin up to 94mm Wedge head2775
Big Block Up to 526Twin up to 94mm Hemi head2775
Big Block Up to 526Twin Up to 98mm2950
Big Block Up to 526Twin Up to 104mm3050
Turbo on GasolineSmall BlockSingle 118mm2125
Small BlockTwin 88mm2275
Small BlockTwin 94mm2350
Big Block Up to 526Single 118mm2325
Big Block Up to 526Twin 88mm Wedge head2575
Big Block Up to 526Twin 88mm Hemi head2575
Big Block Up to 526Twin up to 94mm Wedge head2700
Big Block Up to 526Twin Up to 98mm2875
Big Block Up to 526Twin Up to 104mm2975

*All boosted entries are permitted the use of dual power adders and must add 50lbs to their original 
base weight. Nitrous will always be considered the second power adder on boosted entries.

*Any entry with over cubic inches will be assessed a 100lb penalty. Race Officials must be informed prior to competition of any combination over 526ci.

Hi-helix/Roots and Screw-Type Supercharger entries using big block Chevy heads may deduct 50lbs from their original base weight.

1962 and older bodied entries may deduct 25lbs from their original base weight.

365c.i. and smaller, small block entries may deduct 100lbs from their original base weight.

All entries will be deemed to be following the rules listed for Engine/power adder weight breaks.  All cars must have weight posted on an area of the car that is visible to the scale Official.  At the discretion of the WCPM Director, any car at any time can be called to the scales.  During eliminations, all round winners will be scaled.  Number 1 Qualifier will be scaled.



MAX CUBIC INCH ENGINE DISPLACEMENT: 526ci for turbocharged entries. 565ci for pro charged entries, 526ci for screw and roots supercharged entries, & 960ci for nitrous. Unlimited cubic inch for NA entries.

MAX BORE SPACE: 5.0 on all boosted entries, 5.3 on all nitrous entries.

ENGINE Harmonic balancer meeting SFI Spec 18.1 mandatory.

EXHAUST Double-pipe or thermal-wrapped insulated headers mandatory on supercharged, methanol-burning bodied cars. Insulation must extend to start of bend in headers at bottom of body.

OIL-RETENTION DEVICE All vehicles must utilize an NHRA accepted lower engine oil-retention device; may use a belly pan in lieu of a device attached to the engine. The belly pan must extend from frame rail to frame rail and extend forward of the harmonic balancer and rearward to rear engine plate and must incorporate a minimum 2-inch-high lip on all sides. A non flammable, oil-absorbent liner mandatory inside of retention device. See NHRA General Regulations 1:8.

SUPERCHARGER Use of high-helix supercharger permitted. Screw-type superchargers permitted. Screw-type supercharger must meet SFI Spec 34.1 and be reinspected by the manufacturer every three years. Manifold burst panel meeting SFI Spec 23.1 (in addition to panel in supercharger) plus restraint system meeting SFI Spec 14.21 mandatory on all screw-type superchargers. All other superchargers, restraint system meeting SFI Spec 14.1 mandatory. Supercharger restraint straps must be covered with a fire-resistant material. The blower restraint straps and fuel lines must be installed such that when the restraint straps are fully extended no load is placed on any of the fuel lines. See NHRA General Regulations 1:10.


CLUTCH, FLYWHEEL, FLYWHEEL SHIELD Flywheel and clutch meeting SFI Spec 1.1, 1.2, 1.3, or 1.4 mandatory. Flywheel shield meeting SFI Spec 6.2 or 6.3 mandatory on all supercharged or turbocharged cars and all cars using nitrous oxide. Flywheel shield meeting SFI Spec 6.2 or 6.3 mandatory on all cars using SFI Spec 1.2 clutch with more than two discs or SFI Spec 1.3 or 1.4 clutches with two discs maximum. Flywheel shield meeting SFI Spec 6.2 mandatory on all cars using SFI 1.3 or 1.4 clutches with more than two discs. Cars with rotary engines must be equipped with a flywheel shield made of 1/4-inch-minimum thickness steel plate surrounding the bellhousing 360 degrees. Multi-disc clutch assembly for supercharged, nitrous-oxide injected, must meet SFI Spec 1.5. See NHRA General Regulations 2:3, 2:5, 2:6, 2:10.

DRIVELINE All full-bodied vehicles, where the OEM floor has been removed, each end of driveshaft must have round 360-degree driveshaft loops within 6 inches of U-joints. Additionally, driveshaft must be covered by 360-degree tube, covering the front U-joint and extending rearward a minimum 12 inches. Minimum thickness of tube is .050-inch chromoly or titanium. Driveshaft tube must utilize a minimum of four attachment points to the chassis, either bolted with minimum 5/16 SAE bolts or welded or 1/4-inch push/pull pins. See NHRA General Regulations 2:4.

REAR END Aftermarket axles and axle-retention devices mandatory. Welded spider gears prohibited. Wheel studs must be 5/8-inch minimum. Aftermarket full-floating or live axle assembly permitted. Independent rear suspension prohibited.

TRANSMISSION, Aftermarket Planetary Transmission shield meeting SFI Spec 4.1 mandatory. See NHRA General Regulations 2:12, 2:13.

TRANSMISSION, Automatic Transmission shield meeting SFI Spec 4.1 mandatory. Automatic transmission flexplate meeting SFI Spec 29.1 and flexplate shield meeting SFI Spec 30.1 mandatory. See NHRA General Regulations 2:12, 2:14.


BRAKES Four-wheel hydraulic brakes mandatory on any bodied car. See NHRA General Regulations 3:1. (Carbon fibre brakes are strongly recommended)

STEERING If removable steering wheel is used, commercially available quick-disconnect steering-wheel adapter meeting SFI Spec 42.1 mandatory. See NHRA General Regulations 3:3.


PARACHUTE Mandatory. See NHRA General Regulations 4:8.

ROLL CAGE The following SFI Chassis Specs are effective for all new chassis and for all current chassis at next recertification: full-bodied cars must meet SFI Spec 25.1E, 25.2, or 25.3; Chassis must be recertified every three years by NHRA/IHRA and have a serialized sticker affixed to cage before participation. Plating of chassis prohibited on any vehicle manufactured after Jan. 1, 1999; painting permitted. See NHRA General Regulations 4:1.

ROLL-CAGE PADDING Roll-cage padding meeting SFI Spec 45.1 mandatory anywhere driver’s helmet may come in contact with roll-cage components. See NHRA General Regulations 4:11.


UPHOLSTERY For all front-engine vehicles supercharged or turbocharged (gasoline- or methanol-burning), a flame-retardant material-covered seat is mandatory.

WINDOW NET An SFI 27.1 ribbon-type or mesh-type window net is mandatory on any full-bodied car running 6.00 (*3.66) to 7.49 (*4.49). SFI 27.1 window net, when required, must be updated at two-year intervals from the date of manufacture. See NHRA General Regulations 6:3.


AIRFOILS Non-OEM airfoils or wings permitted on stock bodied vehicles; must be permanently attached to frame or roll cage, non adjustable during run.


DATA RECORDERS Data recorders are permitted.

FIRE EXTINGUISHER SYSTEM Minimum 5-pound NHRA-accepted system mandatory on all cars.  Minimum 20-pound NHRA-accepted system mandatory on all supercharged methanol-burning cars. System must be divided with a minimum one nozzle directed into the driver compartment and minimum one nozzle directed into the engine compartment. See NHRA General Regulations 9:3 for NHRA accepted fire extinguishing agents.

TOW VEHICLES Permitted. See NHRA General Regulations 9:12.


CREDENTIALS Valid NHRA or IHRA competition license mandatory, Advanced ET.

DRIVER RESTRAINT SYSTEM Three-inch driver restraint system meeting SFI Spec 16.1 mandatory.  Restraint system must be updated at two year intervals from date of manufacture. See NHRA General Regulations 10:5.

HELMET For all closed-bodied cars, a full-face Snell M2005, M2010, K2005, SA2005, SA2010, SFI 31.2A, or 41.2A helmet mandatory; shield mandatory (goggles prohibited). See NHRA General Regulations 10:7.

NECK COLLAR/HEAD AND NECK RESTRAINT DEVICE/SYSTEM A head and neck restraint device/system meeting SFI 38.1 is mandatory and must display a valid SFI label. At all times that the driver is in the race vehicle, from the ready line until the vehicle is on the return road, driver must properly utilize an SFI 38.1 head and neck restraint device/system, including connecting the helmet as required for full functionality of the device. The SFI 38.1 head and neck restraint device/system, when connected, must conform to the manufacturer’s mounting instructions, and it must be configured, maintained, and used in accordance with the manufacturer’s instructions. See NHRA General Regulations 10:8.

PROTECTIVE CLOTHING Jacket and pants or suit meeting SFI Spec 3.2A/15, gloves meeting SFI Spec 3.3/5, and boots or shoes meeting SFI Spec 3.3/5 mandatory.Please Note:  Any NHRA Advanced ET/Pro Mod safety rules that conflict with the above safety rules will always circumvent the above rules.  NHRA rules are always considered the standard in safety.