Pro 4 Wedge Car Rules


CHASSIS: Must be steel tube chassis with Ford Fox front clip only

  • No unibody cars

  • Spring pocket area can be modified to attach frame rails

  • Main frame rails 1,750 round or square .095 wall thickness minimum

  • Rear frame clip 1,500 diameter .095 wall thickness minimum

  • Main frame rail must run from the back of rollcage to centerline of the spring pocket minimum on front clip

  • Lower A frame to remain in stock location

  • Steering rack to remain in stock location

  • Wheel base minimum 98” maximum 102”

  • Maximum engine set back is 23” from back of the block to the center line of lower ball joint

  • Maximum engine offset is 2” right or left of frame center line

  • No front wheel or 4 wheel drive allowed


ROLLCAGE: Main rollcage, all left side door bars and uprights, right side upper door bar to be a minimum of  1.500 diameter .095 wall thickness round steel tube.

  • 3 door bars left side with 2 sets of uprights from frame to top roll bar. (Frame rail is not considered a door bar)

  • 2 door bars on right side with second bar 1.250 diameter .095 wall thickness minimum

  • Second door bar maybe run at an angle from top bar to frame rail

  • Left side door must be plated with minimum 18 gauge steel from top door bar to lowest door bar and from in front of seat to back of rollcage


ENGINE: 4 cylinder 2650cc maximum engine size

  • Single cam engines only

  • No aluminum or after market blocks

  • No titanium parts except for valve spring retainers

  • roller cams ARE OK.

  • Stock cast iron or aluminum heads only

  • Head must be stock for block its being used on

  • Head may be ported and have larger valves

  • After market crank, rods and pistons allowed

  • 2 or 4 barrel carburetors, and intake or adapter

  • No fuel injection

  • No dry sump system, oil cooler and remote filters ok

  • No rotary or air cooled, no super or turbo chargers



IGNITION: Distributor ignition only. No crank triggers

  • Can be MSD. No magnetos

  • No computer systems

  • No traction control of any kind

  • Ignition switch must be clearly marked for on/off position

  • Car must have starter and be able to start car at anytime


FUEL: 16 gal fuel cell maximum

  • Fuel cells only. No plain tanks. 8” minimum ground clearance

  • Fuel cell to be securely mounted to frame with minimum 2-2” wide 1/8” think straps completely around cell, or 1” square tube .095 wall completely around cell minimum

  • Must be bolted in at least 4 places with minimum 3/8” diameter bolts. Safer is Better

  • Racing fuel allowed. No alcohol based fuel or any performance enhancing additives. No nitrous oxide. No alcohol. GAS only.

  • Electric fuel pump allowed. Must have separate switch on/off and must operate only when ignition switch is in on position.


INTERIOR: Floor plan maybe steel or aluminum 18 gauge steel or 060 aluminum minimum

  • Drivers area must be sealed from engine compartment

  • Decking may be flat or dropped

  • No open holes in decking except for jack bolt access in rear. Max 2” diameter


BRAKES: Must have 4 working breaks on car

  • Any bias adjusting allowed

  • No single plate rotors. No scalloped rotors

  • Vented type steel only

  • Calipers must be small or large GM single piston style only. Stock or stock replacement steel or aluminum allowed


CLUTCH/TRANSMISSION: Stock transmission from engine being used only 3, 4 or 5 speed transmissions are ok.

  • Racing clutches allowed includes ram coupler

  • No internal clutch transmission

  • Fly wheel or flex plate allowed

  • Bell housing to have 1/4x2” min. 125° shield around fly wheel area

  • Steel drivelines only. Must have minimum 1 driveline hoop ¼’x2’ wide or 1” round .095 within 12” of back of transmission


TIRES/WHEELS: Steel wheels only max 10” wide 3”, 4”, 5” offset only

  • Tires are hoosier take offs slicks. 3025-3035

  • 3045 only. Can be purchased at Rapp Racing.


SHOCKS: Bilstein series SZ, SG, SM, or SL

  • AFCO Series 10, 12, 14

  • QA-1 series 50, 59

  • PRO series TA

  • Additional shock types must be approved and must retail for under $120.00 to be considered.


FRONT SUSPENSION: Stock lower A Arms only (fox clip)

  • Any style upper a-arm, mounting position optional

  • Any style ball joints upper and lower

  • Stock rack for fox clip only mounted in stock location

  • Steering quickners allowed

  • Spindles may be after market or fabricated

  • 5x5 or wide five only. 5/8 studs mandatory

  • 5” diameter springs only. No coil overs of any kind

  • Jack bolt and cup allowed

  • Tie rod maybe swedge tube with rod end

  • Aftermarket or stock sway bars allowed. Must be mounted in stock location.

  • No bump stops or bump stop type suspension of any kind


REAR SUSPENSION: No open or IRS type suspension

  • 5x5 floater 8” or 9” or quick changes 5x5 or wide 5 allowed. No non-floater hubs allowed (safety)

  • 3 link or stack leaf only. No combinations of the types

  • 5” diameter coil springs only

  • No fiberglass/ composite leafsprings

  • No bisguit bars, spring bars or floating mounts of any kind

  • Coil spring must be mounted to top of rear end housing within 5” of the centerline of spring and housing center line

  • Panhard/J-Bar minimum 15” long. Can be mounted in front or rear of housing

  • Rear sway bars allowed

  • No bump stops or stop type suspension allowed


BODIES: Complete bodies only. Car must have roof.

  • Max width or body – Front 84” Rear 72” measured at top of body

  • Max height of body – 38” minimum 32”

  • Roof size – minimum 44” wide 42” long. Maximum 50” wide 50” long

  • Roof height – Minimum 46” maximum 50”

  • Roof may have 1”fins. Right and left sides. Qty 1-2 only

  • Nose may be slope type or MD3 type

  • Maximum 2 ½” tall nose fins on slope nose. Must not pass front tire centerline

  • Nose must not extend more than 52” from front wheel centerline to tip of nose

  • Spoiler: Clear lexan if running over 5” spoiler. 10” maximum blade length. 1” top lip allowed at 90 degree angle to blade forward or back. Spoiler can be adjustable. Can have a maximum of 2 center supports no taller than 10” and no longer than 16”

  • Left side board: 12” tall max, with 1” top fold 90 degrees to the blade. Maximum length 48”

  • Right side board: 10” tall max, with 1” top fold 90 degrees to blade. Maximum length 24”

  • Side boards and center supports must be clear lexan

  • No window or windshield covers

  • No nerfbars on outside of body




SAFETY: All trackside rules must be followed

  • Must have full seat belt and harness assembly. In good condition. 3” belts only. No 2”except sub belt

  • Aluminum left turn or full containment seats only. Must be properly mounted to frame of car

  • Minimum 2 ½ pound fire extinguisher within reach of driver. Fire system recommended

  • Driver side window net required. Arm restraints are not a substitute for net

  • (3)  ½ inch diameter tubes in front of driver minimum

  • Battery must be outside of drivers box

  •  No lead in drivers box

  • All lead must be mounted with minimum 2 ½” bolts, painted white, and car number on it

  • No mirrors




Anyone driving in an overly aggressive manner will be black flagged or asked not to come back


These rules are to be followed by anyone racing with the Pro4 wedge class. If you have any questions about these rules please call Rapp Racing (541) 664-2235