2018 Four Cylinder Pro Stock Rules

FCPS continues to be an exciting division of Saturday night racing at Wiscasset Speedway!  The following rules are a continued effort by division participants working together for division growth with respect to providing an affordable level of racing with integrity and parity for which these cars were designed.  While we understand these rules may not perfect, we request they not be interpreted as opportunities to cheat and/or discover loopholes to gain an advantage.  We shall always welcome and work to accommodate all who respectfully meet the spirit of the rules and desire to race with us.  Be warned, this division is not for the faint-hearted, as the focus of improving oneself is often a formidable task.  Should you choose this division, we believe you will find plenty of speed, challenge, satisfaction and lots of fun racing at Wiscasset Speedway!

12/1/17 Rules Set.


 DRIVER SAFETY REQUIREMENTS – drivers must wear the following required items at all times while on the racing surface. 

  1. One or two piece long sleeve SFI approved fire resistant suit in good condition and free of rips, tears or holes.
  2. Fire resistant shoes and gloves.
  3. Helmet must meet or exceed the Snell 2010 standard.
  4. Face shield, glasses or goggles.

Highly Recommended & Encouraged not yet required but you know it’s coming 😊

  1. Head and neck support/restraint safety device.

Recommended not required

  1. Fire resistant underwear, socks, and head stocking.


  1. All bodies and body panels must remain stock.
  2. Panels must be attached at stock seams using pop rivets with a minimum diameter of three sixteenths (3/16) inch.
  3. Body fillers may be used for repair over any damaged areas of the body. No other fillers allowed.
  4. Body must be securely attached to frame with pop rivets with a minimum diameter of three sixteenths (3/16) inch.
  5. Nose piece must be attached to front bumper and tail piece must be attached to rear bumper.
  6. Front windshield must be attached to lower window bed using three sixteenths (3/16) inch pop rivets.
  7. Hood and trunk lid must be fastened with four (4) three eighths (3/8) inch diameter hood pins, each using steel clips to secure.
  8. Hood and trunk lid must fit firmly on to front and rear windows, with no gaps, openings or holes.
  9. The body can be no less than four and one eighth (4 1/8) inches from the ground without the driver unless otherwise noted herein.
  10. A seven (7) inch by one point five (1.5) inch notch can be made in the bottom center of the both door panels for jacking purposes. No other body modifications permitted.
  11. A one point five (1.5) inch aluminum strip with a maximum thickness of an eighth (1/8) inch thick may be attached to the lower portion of the front nose. The strip can be attached to the entire front portion of the nose up to the bottom front portion of the front fender. The Strip must be flush with the bottom of the front nose and fender and must have a minimum height clearance of two (2) inches from the bottom edge of the front nose to the ground.
  12. Panel braces will be permitted on designated areas of the body and must be welded to the frame.


  1. Roof Height – Measuring point shall be ten (10) inches back from top of front windshield seam in center of roof. Must be forty two and three quarter (42¾) inches, plus or minus one half (½)inch from the ground without driver.
  2. Nose Height – Must be a minimum of two and one quarter (2¼) inches from the bottom edge of the front nose to the ground without driver.
  3. Bottom of Tail – this piece must be a minimum of eleven point five (11.5) inches plus or minus one half (½) inch from the ground.
  4. Spoiler Size – must be three and three quarter (3¾) inches tall and forty eight (48) inches wide with a minimum thickness .060” and a maximum thickness of .080”. Material to be aluminum only.  Absolutely no spoiler braces forward or backward of any type are permitted on the spoiler.
  5. Spoiler Angle – must be between fifty five (55) and seventy (70) degrees and will be checked with an appropriate angle measuring device on the front side of the spoiler.


  1. All grill opening cut outs must be centered left to right – plus or minus one half (½) inch on nose.
  2. A single lower grill cut out with a minimum of twenty (20) inches wide and a maximum of twenty two (22) inches wide by a minimum of three (3) inches high and a maximum of six (6) inches high.
  3. The grill openings may use an aluminum border plate around the screen.
  4. Tape may be used over nose and grill opening cut out screen to regulate the amount of air entering into grill opening.


  1. Chassis – Must be a tube type chassis.
  2. Interior Sheet Metal – All interior sheet metal can be no less than .040 thick aluminum.
  3. Bumpers – Front and Rear bumpers must remain in stock material, wall thickness, dimensions and location. No reinforcements of any kind will be permitted.
  4. Frame Height – Bottom of main frame rails must maintain a minimum height of three and one half (3½) inches from ground with the driver.
  5. Track Width – Total width outside to outside of either the front tires or the rear tires shall not exceed sixty (60) inches.
  6. Wheel Base – May not exceed eighty and three sixteenths (80 3/16) inches on either side and may be no less than seventy nine and three quarters (79¾) inches on either side. Measurement from center of the front hub and be a go or no-go.


  1. Rear End – Only the stock Speedway Engineering midget six (6) spline quick change rear end with aluminum spool and 4.11 ring gear and pinion is permitted.
  2. Gears – Gears must remain stock. No polishing or machining of gear is permitted.
  3. Rear Hub/Axles Tubes/Axles – Axles must remain stock. No alterations or lightening permitted in any form. Allowable rear end components are:
    1. The Speedway Engineering 5310A-10 Rear Hub, 8103-2 Mod Lite/Mini Stock axle tube and 790-R28 Mini Stock axle.
    2. The Speedway Engineering 7803-10-1 Street Rod Axle Tube with the Currie Enterprise CE-1002 rear axles.
  4. Trailing Arm and Shock Mounts – Trailing arm and shock mounts may be welded to the axle tube or may be welded to two (2) inch wide tube clamps.
  5. Rear Brake Caliper Mount – The rear mounts may be welded to the axle tube or may be welded to one (1) inch tube clamps.
  6. Drive Shaft – Only the Fast Shaft steel drive shaft or comparable brand is allowed for competition. All drive shafts must be painted white.


  1. Rear End In Car – The center of the rear end can be no more than one eighth (1/8) inch off of the centerline of the tail section either way (side to side). Measurement shall be from inside of the right frame rail tube to the centerline of the rear end assembly.
  2. A-Frames – Lower control arms on front end may not be more than three sixteenths (3/16) inch different in length from the center of the rod end to the center of the ball joint on the front leg of the control arm.


  1. Front Suspension – Upper and lower control arms, steering arms, spindles must remain stock type construction. No modifications will be allowed.
  2. Ball Joints – Allowable ball joints are the K772 type ball joint or any similar racing type ball joint. No adjustable ball joints allowed.
  3. Front Hub – Only the Speedway Engineering 5307-2 Front hub with six (6) inch by five and one half (5½) inch. Brake rotor adapters are allowed.
  4. Shocks – Only non-adjustable stock steel SB64, SB63, SB62, SB624 and SB631 series Pro-Shocks or QA1 7564 accepted as alternative to Pro SB64. One shock only permitted per wheel. The only adjustable device allowed on the shock is the spring adjusting nut.
  5. Springs – Only one and seven eighths (1 7/8) inch inside diameter ten (10) inch long steel coil over springs permitted. The spring must be mounted in coil over form over the shock.
  6. Front Sway Bar Option – Note: Due to Wiscasset Speedway track condition, the front sway bar option was approved at 2014 drivers meeting as a safety measure with the Woodward Mini Pro Stock Sway Bar System as the only allowable sway bar system used for the 2018 season.


  1. Steering Box – The Stilleto rack & pinion spec steering box is the only steering box permitted. The steering rack must remain stock and in the stock location.
  2. Tie Rods/Rod Ends – Allowable tie rods must be swedged type aluminum or steel. Tie rods must use half (½) inch heims and can be steel or stainless steel heim joints.
  3. Steering Shaft – Only a three quarter (¾) inch steel shaft may be used. Steering shaft must remain between rack and firewall. Steering shaft may be raised, lowered, shortened or lengthened from firewall back but not changed in material.
  4. Quick Coupler/Steering Wheel – Steering coupler and wheel must be approved.


  1. All brakes must remain operational at all times.
  2. Master Cylinder – The Wilwood 260-10375 or any M32900 Ford type master cylinder may be used. The only modification allowed is removal of the residual pressure valve inside the M32900 master cylinder. The master cylinder must have a “T” fitting which connects both front brake calipers.
  3. Rear Brakes – Shall have a single line from the master cylinder to the rear of the race car with a “T” fitting for the left and right rear calipers.
  4. Brake Line Proportioning Valve – Is permitted between the front and rear brake calipers. It is not to be used for adjusting left to right braking on the calipers.
  5. Brake Bias Gauge – May be added but can only be installed on the front dash.
  6. Calipers – A one point seven five (1.75) inch piston three point seven five (3.75) inch mounted caliper is permitted. Allowable models will be: Outlaw model #1000 or Wilwood 120-4060 or Wilwood 120-9690.
  7. Caliper Location – Calipers must be mounted in the stock location. Calipers may be shimmed for pad clearance.
  8. Caliper Brackets – All brake caliper brackets must remain stock in material and form and in location.
  9. Brake Pads – All brake pads must be stock.
  10. Front Brake Rotors – Front brake rotor must be solid steel and have a nine and three quarter (9¾) inch outside diameter. Rotors can have a maximum thickness of three eighths (3/8) inch and a minimum thickness of 0.300″. Brake rotors may be modified to include drilling, cutting, grooving or grinding.
  11. Rear Brake Rotors – Rear brake rotors must be solid steel and remain stock. Rotors must have a ten and one half (10½) inch outside diameter and six and one quarter (6¼) inch inside diameter. The outer surface of the brake hat must have a six and five eighths (6 5/8) inch outside diameter and a two and five eighths (2 5/8) inch inside diameter. Rotors can have a maximum thickness of three eighths (3/8) inch and a minimum thickness of 0.300″. The distance from the outer surface of the brake hat to the center of the rotor must be two and one half (2½) inches. Rear brake rotors may not be modified to include drilling, cutting, grooving or grinding.
  12. Brake Duct – Only one (1) brake duct hose allowed per wheel. All duct hoses must be securely fastened in place on both ends. No blowers, fans or mechanical devices allowed to cool brakes. No manufactured, fabricated or any type of ducts allowed on opposite end of any hose from inlet. Brake hoses must be securely fastened on brake caliper end and pointed directly at brake rotor. Duct hoses may not exceed three (3) inches diameter.


  1. The engine assembly will consist of the engine long block and all components bolted to it including the intake manifold, carburetor and its adapters, distributor assembly, flywheel, clutch and pressure plate.
  2. The only engine package allowed is the Mazda B2200 Engine with a stock Mazda manual transmission.
  3. The engine serial number must be registered with Wiscasset Speedway.
  4. All engine parts and accessories, internal and external, must remain stock and in stock location. The engine and engine parts must remain sealed. Engine seals shall not be altered or tampered with in any way.


  1. Only the Weber 32/36 DGV5A carburetor is permitted.
  2. The carburetor, all parts of the carburetor, and the adapter plate must remain stock and in the stock location.
  3. The air jets, main fuel jets and low speed idle jets may be changed, but must be stock jets.
  4. No other changes or modifications are permitted to the carburetor.


  1. Only the Weber Part #99217331 air cleaner is permitted.
  2. The air cleaner base, element, and top must remain stock and must remain in stock location.
  3. Ducts, hoses, or other devices directed to or attached to air cleaner will not be permitted.


  1. All engine electrical components must remain stock, in the stock location, and must operate in stock manner at all times. No ignition or engine electrical component enhancing devices shall be permitted.
  2. Stock or aftermarket equivalent to stock replacement coil may be used.


  1. Exhaust system with a muffler is required and must extend past the drivers compartment turning down toward the ground with the end of exhaust system under the race car, not out the side or the rear of the race car. Engine exhaust system may be painted, coated, or wrapped with a high temperature coating.


  1. Only an aluminum type radiator is permitted.
  2. Radiator overflow hose is permitted and must be routed to a catch can or through the left front fender.
  3. A Radiator hold down must be used.
  4. A box type duct is permitted from the nose piece to the radiator.
  5. The duct can be no larger than the radiator its self where against the radiator and no wider than the outward bumper supports at nose piece.
  6. The only items that can be ducted through this box are the radiator, oil cooler (optional), or front brakes.
  7. This box will only consist of two sides and one top and one bottom. No other dividers, fins, air directing devices or anything else permitted inside of duct work.
  8. Duct work must be sealed to radiator.
  9. An engine oil cooler is optional and must be approved by Wiscasset Speedway Tech.
  10. A fan is optional with only one (1) twelve (12) volt electric fan permitted. The maximum diameter may not exceed the width of the radiator core and the fan must be securely fastened to the radiator core.


  1. Only the stock Mazda transmission is permitted.  All production transmission gears need to be intact and in working condition.
  2. The transmission and all parts of the transmission must remain stock and in the stock location.
  3. Polishing of the internal gears is not permitted.
  4. The only part in, on, or attached to the transmission that may be altered is the shift lever. No alterations of any other kind are permitted.
  5. All five forward gears & reverse must be operational at all times.
  6. Transmission cannot be offset in the chassis.


  1. Clutch, pressure plate, and flywheel must remain stock based on the engine package being run. No modifications to any part of the clutch except resurfacing of flywheel will be permitted. No light weight or aluminum flywheels are permitted.
  2. The Wilwood WIL260-1304 Clutch master cylinder or other similar type clutch master cylinder will be permitted.
  3. The clutch lines and slave cylinder must remain stock and in stock location based on engine package.


  1. Fuel Cell types – Any racing type fuel cell with a bladder and aluminum can with a fuel capacity minimum of four point five (4.5) gallons and a maximum of five point five (5.5) gallons will be allowed.
  2. Must use foam and roll-over and check valves.
  3. Fuel cell must have a minimum eighth (1/8) inch steel or three sixteenths (3/16) aluminum protection covering the complete front and rear surface of the cell can.
  4. All fuel cells must have two (2) straps in both directions, fully surrounding cell. Straps must be minimum one (1) inch by eighth (1/8) inch steel using minimum five sixteenths (5/16) grade 5 hardware.
  5. All cells must be top fill. No dry breaks.
  6. Car must have a minimum one and half (1½) inch by point zero six five (.065) wall fuel cell ‘hoop’ with two (2) braces to the frame.
  7. Square or rectangle cell and containers only. No U shape, horseshoe or any other configuration allowed.
  8. Fuel Line may be five sixteenths (5/16) inch Automotive or Aircraft grade 6 fuel line with a no larger than five sixteenths (5/16) inch inside diameter must be used.
  9. Any canister type fuel filter can be used. No glass filters permitted.
  10. Pickup and return line between fuel cell and fuel pump must pass through steel fuel line tube, which must be in stock location.


  1. Only an approved high back aluminum racing seat with a minimum thickness of .120 is permitted.
  2. Seat must have a full cover. Seat must be attached to frame with a minimum of four (4) steel grade 8 bolts that have a minimum diameter of three eighths (3/8) inch.
  3. Note: Manufacturer specifications shall take priority regarding all safety equipment.
  4. An approved five point safety harness with three (3) inch minimum wide belts equipped with a quick release buckle is mandatory in all cars.
  5. The driver must use the seat belt restraint system at all times on the race track, in accordance with the instructions and/or recommendations of the system supplier and/or manufacturer.
  6. The seat belt restraint system must be installed in accordance with the directions provided by the system supplier and/or manufacturer.
  7. The date of manufacture must remain visible on the belts at all times. Seat belt restraint systems must not be used beyond two (2) years after their date of manufacture or in accordance with manufacturer’s specifications


  1. Front, rear and quarter panel windows must be Lexan with a minimum of .093 thickness.
  2. Front, rear and quarter panel windows must remain stock and attached in stock location with three sixteenths (3/16) inch pop rivets at all times.
  3. Cars must have a minimum of three (3) braces for front window and a minimum of two (2) braces for rear window. Braces must be a minimum of one (1) inch by quarter (1/4) inch .063 aluminum.
  4. Only tinting allowed on any window is: front windshield top, full width five (5) inches down from top of windshield.
  5. No other decals can exceed five (5) inches from the top of the windshield.
  6. No decals are allowed on the back window.
  7. An approved full window net is mandatory.
  8. Window nets shall not be older than three years from the date on manufacture. All window nets must be dated.
  9. Minimum size is sixteen (16) inches by sixteen (16) inches The net must be securely fastened to the top left side door bar with a steel rod minimum diameter of three eighths (3/8) inch. It must have a quick release latch on top. The latch must be securely fastened during practice, qualifying, race events and or and any time the car is on a race track and in motion.


  1. Roll bars must be padded. The inside of the left door bars may be padded with a single piece of race car approved door padding.


  1. Any rear view mirror may be used with approval of Wiscasset Speedway Tech. The mirror must be mounted securely inside cockpit. No mirrors or parts of mirrors may extend past the outer body surface.


  1. The Stock Gauges will consist of a five (5) inch Tachometer, Oil Pressure and Water Temperature gauge. The only other additional gauges allowed will be that of a brake bias gauge and or and Oil Temperature gauge.
  2. Gauges may be affixed directly to the dash.
  3. No other gauges shall be permitted without prior approval from Wiscasset Speedway Tech.


  1. Only one ignition switch and one starter button per car is allowed.
  2. Ignition switches may be mounted on the right side interior roll bar for easy access.
  3. An operational on-off battery switch is mandatory and must be mounted on the dash panel.
  4. An on-off switch is permitted on the dash area or roll bar for the radiator fan.
  5. No additional wiring shall be permitted without prior approval from Wiscasset Speedway Tech.


  1. Battery must be a Group 26 12Volt automotive top post battery. Battery must remain in the designated battery location in the stock form. Battery hold down must be one (1) inch by one (1) inch by eighth (1/8) inch thick steel angle fastened with a minimum of two (2) five sixteenths (5/16) inch diameter steel rods and nuts.


  1. All pedals must be bolted in stock locations. 10/29/17 Driver Meeting allows a pedal modification for one driver only.  While pedals must be bolted in stock location, pedals may be lengthened to accommodate driver.  Modification remains until driver no longer registered with division.
  2. A heat shield may be affixed to the right side driver foot box and sheet metal area. The heat shield must be fastened securely and should not interfere with the operation of any part of the gas pedal.


  1. A fire extinguisher inside the car is mandatory. It must be a minimum two and one half (2½) pound system – charged and operational at all times.
  2. The fire extinguisher must be mounted in accordance to the manufactures specifications.
  3. Under no circumstances is the extinguisher allowed to be mounted along the left side of the race car between the door bars and the driver’s seat.
  4. The activation valve must be easily accessible for the driver. One nozzle is mandatory inside cockpit. Additional lines and nozzles may be used on fire extinguisher system.


  1. A seven (7) inch x one point five (1.5) inch notch can be made in the bottom center of the both door panels for jacking purposes.
  2. Duct Openings (Optional) – A maximum of one opening on each side of front nose piece is permitted; Left side opening may be no larger than a manufactured single duct for a hose with a maximum diameter of three (3) inches. Right side opening may be no larger than a manufactured double duct for hoses with a maximum diameter of three (3) inches. The only items that can be ducted through the nose piece are the front brakes or an oil cooler.
  3. Oil cooler hose must be securely attached to oil cooler. If no hose is attached to duct, duct opening for said hose must be sealed off.
  4. A maximum of one opening on each side quarter panel window, no larger than a standard manufactured Naqua type duct for a hose with a maximum diameter of three (3) inches is permitted. No duct hose may exceed three (3) inches diameter.


  1. Wheels – Only thirteen (13) inch diameter by seven (7) inch wide with three and one half (3½) inch offset and one standard valve stem are permitted. Wheels must remain stock and may not be altered or tampered with in any way.
  2. Wheel Spacers – A three eighths (3/8) inch thick six and one half (6½) inch outside diameter and two and one half (2½) inch inside diameter wheel spacer must be used when running Bassett wheels with three point five (3.5) inch back space. When running Diamond wheels with a double wall center flange, a one quarter (1/4) inch thick wheel spacer must be used. One wheel spacer is mandatory on each side.
  3. Tires – Wiscasset Speedway Official Track Tire = Wiscasset Speedway Official Track Tire = Hoosier 23.5/7.0/13 Rib Compound 800 and 23.0/7.0/13 Rib Compound 800.
  4. Wiscasset Speedway shall keep a registered inventory of tires for each FCPS team with all tires being registered to the car number. Pro Stock teams shall be responsible for their own tire management.  Wiscasset Speedway will not impound, manage or provide storage for team tires.
  5. From April 7th to May 4th, Four Cylinder Pro Stock teams shall have the option to purchase a maximum of six (6) new tires to begin their registered tire inventory for the 2018 racing season. Beginning May 5th, on actual Pro Stock racing events thereafter, teams shall have the option to purchase a maximum of one (1) new tire for their registered tire inventory.  Should the option of one (1) new tire purchase not be exercised, the option is forfeited.  All tires shall be registered to the car number.
  6. Pro Stock teams arriving to race after May 4th shall have the option to purchase a maximum of four (4) new tires to begin their registered tire inventory and on actual Pro Stock racing events thereafter, shall have the option of purchasing a maximum of one (1) new tire for their registered tire inventory. Should the option of one (1) new tire purchase not be exercised, the option shall be forfeited.  All tires shall be registered to the car number.
  7. Should a tire be damaged during the race event, it shall be the responsibility of the race team to present the damaged tire that day and within a timely manner to Tech for inspection. All tire replacements must have a written record with Tech regarding inspection and approval for replacement.  Only tires with 50% or more tread will be eligible for replacement.  Replacement of damaged tires will be limited to three (3) for the season. No Exceptions.
  8. All cars are subject to random testing at the discretion of Tech, durometer testing will be conducted On Track after heats and features of the top five (5) cars. Failure to meet the 2018 division preset number (Right Sides 50 and Left Sides 45 with No Allowances) will be subject to penalty as follows: Heats – illegal tire(s) held at Tech for the remainder of the race event and not allowed again until cleared by Tech; forfeiture of heat points and feature start is rear of the field.  Features – Full DQ with illegal tire(s) not allowed again until cleared by Tech.
  9. While division participants agree use of tire conditioning agents is difficult to police – all agree application of such will not be allowed at the track.
  10. Speedway management reserves the right to modify tire rules in conjunction with division needs & concerns.


  1. Cars are weighed race ready, full of fuel and with driver in the seat.
  2. Total Car Weight minimum is 1685 lbs.
  3. Left side percentage is 57% maximum.
  4. Weight may be placed inside the two (2) inch by two (2) inch outside main frame rails.
  5. Weights installed other than in the frame rails must be welded or bolted to the frame or roll cage, painted white and identified with car number.
  6. No driver adjustable weight.
  7. No lead shall be bolted to the seat, floor pan, seat belt, seat mounting bolts or brackets.
  8. Lead may be mounted behind the seat bolted or welded to the cross members.
  9. All lead must be mounted with a minimum three eighths (3/8) inch grade 8 bolts and nuts.


  1. All car numbers are assigned and registered by Wiscasset Speedway.
  2. Car numbers can be a maximum of two digits. No letters or symbols.
  3. When changing divisions, a new number will be assigned.
  4. Numbers shall be painted in contrasting colors to the car on both doors and the roof. Reflective chrome, gold or prism numbers will not be acceptable.
  5. Door numbers must be a minimum of nineteen (19) inches high and three (3) inches wide. Door numbers to be located between the front and rear door seams.
  6. Roof numbers must be a minimum of twenty one (21) inches high and face the grandstand side of the car.
  7. The car number must also appear on both the headlight & tail light panel located on right side of car.
  8. The car number must also appear in six (6) inch high numbers in both the front and rear windshield located on the right side of the car.


  1. Two way communications shall be allowed; however, Wiscasset Speedway Management will require frequency registration.
  2. RaceCeivers are mandatory equipment.

All race car components, including sealed engines, may be subject to teardown/dismantle inspection at any time.   Refer to General Rules – Tech Information Section.


Motorsports At All Levels Pose A Risk To Your Well Being. Following The Rules Set Forth By Wiscasset Speedway In No Way Guarantees Or Suggests Your Safety.

Wiscasset Speedway Reserves The Right To Modify This Document At Any Time.  Such Modifications Will Become Effective And Enforced On The Next Race Date.

Last Edit 12/1/17

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