Mini Stock Rules
As of 1 March 2015
RULE BOOK DISCLAIMER: The rules and/or regulations set forth herein are designed to
provide for the orderly conduct of racing events and to establish minimum
acceptable requirements for such events. These rules shall govern the
condition of all events, and by participating in these events, all
participants are deemed to have complied with these rules. COASTAL
PLAINS RACEWAY TECH shall be empowered to permit any and all deviation
from any of the specifications herein or impose any further restrictions to
keep the competition close. Any interpretation or deviation of these rules
is left to the Discretion of the COASTAL PLAINS RACEWAY TECH
officials, their decision is final.
1. Minimum age for Mini Stock class is Fourteen (14 years old).
2. Must have CPR officialís approval.
3. Driverís must have parentís consent form filled out prior to on track.
4. Driverís will be able to participate in other CPR classes except for the
Young Guns class.
1. Any 1960 and later with a maximum wheelbase length of 102
2. Front or rear wheel drive car or truck. No all-wheel drive
3. NO 2 seaters or convertibles.
BODIES, ROLL CAGE and CHASSIS:
chassis must have come stock with a 4 cylinder engine of any version.
stock or aftermarket body, including straight sided dirt, made from fiberglass,
aluminum or steel allowed. Open wheel type must submit photos for approval
and will be allowed for one race maximum if approved.
windshield required. Side and rear glass optional. Sunroofs must be covered
with minimum 22 gauge steel. Roof escape flaps as required at Bowman Grey
4. All doors must be bolted, welded or riveted shut.
5. All hoods must be sealed to the fenders, cowl (or
windshield) with no more than 1inches gap. No hood scoops, holes in
hood or anything else funneling air to the carburetor.
6. At least four positive fasteners must be used to hold hood
and trunk, OEM hinges may account for two of these four total.
7. Must have full firewalls front and rear with no holes,
completely sealed, 22 gauge steel minimum for refabricated sections. No
combustible materials to fill holes.
8. Must have factory floor pan from front firewall vertical
section above transmission tunnel behind motor to front mount for back
9. Inner structures of fenders, wheel wells, strut towers and
trunk floor may be removed.
10. Rear spoilers will be a maximum of 5 inches tall and 54
inches wide. Highest point of rear spoiler must be at least 10 inches lower
than the highest point on roof. Rear spoilers may have to be shortened or
removed to meet the 10 inch minimum described.
11. Spoilers must be mounted at the back of the trunk area
12. Complete 6 point center section and rear down bars of roll
cages must be 1- 1/2inches minimum diameter and .090inches inch wall
thickness minimum. No muffler pipe or crimped muffler bends in main cage.
**The tech person
will have the power to disallow any car with compromised structural
integrity or protruding parts that may be dangerous to a competitor.**
13. Minimum of 4 door bars on driver side, with 1/8 inch metal
plate must be welded to the driverís side door bars so nothing can enter
the driver area. Minimum of 3 door bars on passengerís side.
14. All perimeter bars and bumper bars must be shaped with
safe and reasonably rounded ends to eliminate puncturing other driverís,
doors, tires, fuel cells, etc. No push bars outside of front bumper
15. All bars within driverís reach must be padded.
16. Steering quickner allowed.
17. Quick release steering wheel suggested.
18. Aftermarket pedals allowed, may be relocated.
19. All glass except windshield must be removed. No plexiglass
windshields. Lexan or glass windshields allowed. For glass windshields,
only safety- glass laminated allowed. Two vertical braces at least 1 inches
wide x 1/8 inch thick required on windshield.
Side view and rear view mirror allowed.
Side vents for driver cooling allowed.
Brake air ducts allowed.
Track Width maximum 63 inches front & rear, measured from center of
tire to center of tire.
use any size, type or arrangement of wheel spacers to make ride width
Wheelbase must be within +/- 1 inch of stock factory length for car
model claimed. Left and right sides of car must be within 1 inch of length
of each other.
weight & weight percentages are measured with driver & car in race
Advertised engine size in cc and left side weight percentage to be located
on the hood, so tech can read it when you roll on to the scales.
lbs of lead may be added to the center of fuel cell, or 5 gallons of fuel
added for post race weigh- in. Maximum of 35 lbs or 5 gallons
regardless of fuel cell size or number of laps run.
cars will weigh one pound per cc after race and a minimum of 2000 lbs.
weight and engine size specs must be written on hood.
Ford engines, minimum weight 2300 lbs. 1 lb. per cc above 2300cc.
Example 2500cc = 2500 lbs.
Toyota 20R block with 22R head must weigh 1 lb per cc.
2300 head on 2000 block must weigh 2300 lbs.
Pinto/Lima style engine with 1.50Ē intake and 1.75Ē exhaust valves may compete
at 2300 lbs.
Maximum left side weight is 55% of the total weight (see weight penalties
dislodged parts can be added back to the car after the feature race to make
lead must be in blocks and painted white with car #. All weight must be
securely bolted with nylocks or double nuts.
chassis design or car make that has an obvious advantage over any other may
be subject to weight percentage and weight additions for the sake of close
engines must use stock OEM parts with only the exceptions stated here. 4
cylinder piston engines only. No Rotary engines. You may interchange
engines and chassis within your manufacturer line but not across makes.
Example: Any Ford in a Ford but no Toyota in a Ford. No turbochargers or
Engine must be installed in stock location. For engines interchanged
between chassis of the same make, there is to be no less than 1 inch
between back section of cylinder head and vertical plane of stock firewall
Stock O.E.M. or solid motor mounts allowed.
be stock O.E.M. production only, no aftermarket blocks.
block is to be coated, polished or any machine work except what is listed
Minor machining to block for aftermarket rod clearance allowed.
Blocks can not be offset bored but may be sleeved with original bore
Stock O.E.M. type rod, camshaft and crankshaft bearings.
pulleys and waterpump allowed.
Crankcase evacuation system to header allowed.
Aftermarket oil pan allowed.
be stock O.E.M. cast or steel, no aftermarket such as Scat, Lunati, etc.
Stock O.E.M. stroke of crankshaft being used must be maintained within +/-
lightening or knife edging of throws or counterweights.
polish between #4 rod journal and #5 main journal surface areas for the
purpose identifying cracks more easily and eliminating surface stress
risers, not to lighten.
Engine balancing allowed, must be done in a standard production manner.
girdle kit allowed on main bearings.
Crankshafts may be interchanged among blocks within the same make with no
machining needed. Direct fit applications only.
on hood must reflect correct bore and stroke combination. Engines will be
P&G tested regularly.
2.5 crankshafts allowed in Fords.
steel aftermarket rods allowed.
length for Ford is 5.7 inches.
length for Toyota is 5.2 inches.
length for any other model is 5 inches.
polish stock OEM rods.
hollow aftermarket rods.
Toyotas may use H- beam rods.
Minimum 1.950Ē diameter rod journal diameter for Fords.
rod bolt allowed.
PISTONS and PISTON RINGS:
flat top piston with any number of ring glands allowed, must have zero deck
steel wristpin allowed, no titanium pins.
OEM dome piston engine may run any dome piston. The flat part of the dome
piston may extend 0.010 inches above deck height.
style piston rings allowed. Minimum 2 rings per piston.
engine bearings must be stock OEM type sleeve bearing, No roller bearings
titanium fasteners permitted, any other fastener type allowed.
and main bearing studs allowed.
brand allowed. No o-ring style sealing allowed in place of head gasket.
be stock OEM heads, No aftermarket heads allowed.
Heads may be interchanged on blocks within same make in direct fit
applications. Crossbreeding within same make is allowed. Ex: 2300 head
allowed on 2000 block.
Angle milling allowed.
valves per cylinder maximum.
Stainless Steel O.E.M. configuration valves and swirl type allowed.
Valve stems may not be smaller diameter than stock for head being used.
engine with valve stems smaller than stock diameter may compete with
maximum 53% left side weight.
Valves may be Back Cut 30 Degree Maximum.
Valve stems may not be canted in heads.
interior de- burring, polishing, extrude honing or acid porting allowed.
Ports must be stock as cast from OEM.
Lifter bore may be machined for solid adjusters.
or stainless aftermarket valves must retain stock head diameter.
steel or stainless steel retainer/keeper allowed. Valve job angles
valve spring combination or design.
valve diameter stock size for cylinder head used.
Ford Pinto/Lima style engine with 1.50Ē intake and 1.75Ē exhaust valves,
see weight section for requirements.
Reinforcement on cam boss allowed.
Late model stock style bowl cut allowed. 1 angle under the seat, 1 inch
maximum depth of cut but do not touch the valve guide. No blending of bowl
cut to ports or rounding edges that bowl cut creates.
roller cam followers allowed except on GM 151 engines.
type of valve job allowed. Ex: 3 angle
aftermarket hydraulic or solid cam allowed, any lift without weight
Adjustable cam gear allowed.
Stock OEM steel or double roller timing chain and gears with hex adjustment
Anti- pump up hydraulic lifters allowed.
lightweight push rod.
stock OEM rocker arms and lifters that came OEM in the head being used.
Lifter bore may be machined to allow for solid adjusters.
return screens allowed.
Lifter valley baffles are allowed.
Lifters must be stock sizes for head being used.
Roller rocker arms allowed on GM engine only.
valve spring retainer and shim allowed.
Stock OEM factory intakes with factory part number.
injection intakes allowed.
hi- performance aftermarket intake manifolds.
porting, polishing, coating, dipping, port matching, etc.
Intake may only be modified to accept carburetor, no other modifications
Carburetor adaptor plates must not protrude down into plenum.
parts must be mass produced items available as stock production over the
counter parts. No special test or marine type parts. Only North American
distributed intakes on domestic. Asian allowed on Japanese makes only.
CARBURETORS, SPACERS and
Holley 350 CFM # 0-7448, # 0-80787-1 or Holley 500 CFM # 0-4412, # 0-80583-
Choke hardware removal allowed.
vacuum ports must be plugged.
4. †2 Gaskets @ .065 max ALLOWED.
carburetor adapter or spacer, 1.5 inch thickness maximum.
circular holes, 1 oval hole, beveled and/or tapered allowed.
modification to carburetor for mounting.
CFM 30 cc Accelerator pump ONLY.
Carburetors will be checked per NASCAR Late Model Stock guidelines
polishing, grinding, or machine work.
base plate modification.
drilling of additional holes.
Boosters may be changed.
booster modification to size or shape.
Height and location of the boosters must remain per factory specs ONLY.
boosters must maintain OEM outside diameter ONLY.
venturi area to be altered or reshaped in any manner.
removal of casting ring.
modification to allow additional air to be picked up below the opening of
altered gaskets, base plates, or drilling holes into the carburetor.
butterflies to be thinned or tapered.
Idle holes may be drilled in butterflies.
Screw ends may be cut even with shaft, but screw heads must remain
shafts to be thinned or cut at all.
Accelerator pump discharge nozzle may be changed.
Power valve may be changed.
Jets may be changed.
outside air to be pulled through the carburetor other than through the
cars must have a metal air cleaner housing.
Aftermarket air cleaner up to 14inches diameter x 5inches tall max allowed.
Paper element or K & N type allowed.
funneling of any air to the air cleaner or carb.
of air cleaner must be below choke horn.
carb hats, baffles, etc.
and bottom of air cleaner housing must be the same size.
FUEL & FUEL SYSTEM:
Track fuel only.
fuel cooling devices.
Cell: 12 Gallons max.
cell must be mounted in a can made of at least 22 gauge metal.
cell must be mounted in center of trunk area between the frame rails. No
more than 2Ē deviation from center of rear treadwidth.
cell must be protected with a sufficient amount of structure, including a
bar below and to the rear of the can.
cell venting high and to the driverís side recommended.
Pump: HP mechanical or electrical allowed. Must have roll over valve/switch
Must be approved by tech person.
Fuel will be checked randomly.
Battery must be securely mounted and enclosed to guard the driver from
spills or explosions.
Batteries may be mounted in trunk or through floorboard but no lower than
12 volt electrical systems allowed.
Standard or electronic distributor may be modified for reliability only.
Stock type coils only.
ACCELL, MALLORY etc., internal parts, coils or modules are allowed, stock
multiple spark discharge boxes or systems allowed.
Point type allowed.
full aftermarket distributors.
adjustable timing controls.
traction control devices
wiring in car must be securely insulated and fastened.
spark plugs and spark plug wires allowed.
dual point distributors allowed.
Stock cooling system only in stock O.E.M. location
ANTIFREEZE - $100.00 FINE FOR 1ST OFFENSE** may use Water
Wetter type products.
Electric fans allowed.
Overflow hose must be routed to base of windshield on passenger side to
alert driver in case of overflow.
Fabricated mounting for radiator allowed, must be mounted between frame
stock or aftermarket exhaust manifold or header allowed.
into 1 and Tr- Y style allowed.
Exhaust pipes must route to behind the driverís seat, and must extend to
the outer edge of the car.
exposed pipes in driverís area.
Exhaust may run through the inside of the race car if totally boxed, sealed
and approved by tech person.
pipes turned down.
Crankcase to exhaust evacuation systems are permitted. Only quality check
valves will be permitted.
Stock type wet sump only.
External oil filter and coolers allowed, must remain under the hood with
steel braided hose and AN type fittings. No rubber hose or hose clamps
dry sump or accu- sump systems.
race type oil pan allowed.
Screen kits in oil return system allowed.
pan baffles preventing oil from flowing away from the oil pump pick- up
Windage trays allowed.
chassis suspension mounting points must be stock OEM. All left to right,
height and ďXĒ measurements must be within 3/4 inch.
Front lower control arms must be equal length left to right.
Rocker panels may be removed and replaced with square tubing.
frames must be stock, Unibody frames may be tied together end to end half
way max on frame rails.
Firewall, frame rails, floorboards and suspension mounts must remain intact
from center of front wheels to center of rear wheels in a way that proves
there have been no chassis mounting point, length or width modifications.
may patch floor pan if itís rusted or has holes. Do not cut out and replace
Entire floor of trunk may be removed.
pushbars extending outside of bumper covers.
Frame may be notched for oil filter and fuel pump clearance.
Adjustable rear shackles and slider blocks allowed on leaf springs.
Front eye of leaf spring must remain in stock location.
Adjustable coil spring spacers, wedge bolts, adjuster cups, spring rubbers,
weight jacks, lowering blocks allowed.
joints are allowed on sway bar and in place of tie rods for bump steer
Rear panhard bars allowed only on cars which came stock with them. May be
adjustable from under car only and with positive bolt pattern, no jack
Solid engine & transmission mounts allowed.
Aftermarket pedals allowed and may be relocated.
or double master cylinders allowed.
Brake adjusters, flow control and metering valves allowed but MUST BE OUT
OF DRIVERS REACH AND CAN NOT BE USED DURING RACE.
sway bar diameter is 33mm or 1 5/16.
TRANSMISSIONS, FLYWHEELS and
Automatic or manual allowed. All gears must be functional from driverís
transmissions: manual shift kits allowed. Reverse shift patterns
allowed. Internal modifications for durability only. No trick or
lightweight internal parts, O.E.M. factory only. Torque converter must be
stock O.E.M. size. Must be factory O.E.M. stall speed. No stall or hollow
converters. No aftermarket Hi- Pro converters. No valve or any mechanism to
transfer transmission pressure allowed. Neutral safety switch must be
functional at all times. Modified transmission oil pan allowed.
Transmission oil cooler size and placement is optional. Cooling lines must
have no more than 12inches of high- pressure rubber tubing. Aftermarket
flex plate allowed.
transmissions: All gears must be functional from driverís
compartment. Three (3), (4) or (5) speed transmissions.
aluminum flywheels permitted.
type flywheel and pressure plate combination with a minimum weight of 23
lbs. Weight will include flywheel, clutch disc, pressure plate and
aftermarket Hi- Pro clutch packs such as 10,000 RPM, RAM, Center Force,
Reinforcement in area of floorboard for safety is required.
aftermarket transmissions, must be factory standard production only.
lightening of internal rotating components in transmission.
Standard one (1) piece, minimum diameter 2 Ĺ inches. Steel only.
be painted white with car number on it.
Drive shaft safety loops front and rear mandatory.
car or truck rear end, interchanging allowed within make.
Mounts on interchanged rear ends must match stock rear end to exact OEM
measurements. A OEM stock rear end for your chassis may be required for
9Ē Ford rear ends are allowed.
differential: open, welded, full spool, mini spool, locker, limited slip or
helical gear types allowed.
quick change rear ends.
gear ratio allowed.
cambered rear ends, +/- 0.4 degrees maximum deviation.
lower trailing arms allowed must be OEM stock length.
heim joints on lower trailing arms.
aftermarket axle allowed.
Chassis rules above for panhard bar specs.
style third link or upper trailing arms may be aftermarket and/or
adjustable length. Mounting holes at chassis and rear end housing must be
stock OEM location.
Stock OEM style suspension that came on your chassis.
Stock style control arms only. No aftermarket a- arms.
Stock style upper a- arms may be shortened or lengthened for camber/caster
upper a- arms added in place of stock strut design.
Lower a- arms may be interchanged within same make. Must meet maximum ride
lengthen or shorten stock type lower a- arms on Toyotas only.
Strut rods on lower control arms (such as Pinto and Toyota) may be
adjustable in length but retain same mounting points.
Sway bars only, no splined type. 1 5/16 inch or 33mm max diameter. Mounting
optional. End link design optional. May be adjustable on both ends.
upper strut plate/connection may be used in place of strut tower.
Lemans bar between strut tower allowed.
camber and caster settings allowed.
Spindles, rotors and calipers must be OEM but may be interchanged within
different year models or versions of your same chassis.
Disc brakes may be interchanged with drum brakes within your same make.
Steering box and rack may be interchanged among same make.
aftermarket spindles. Spindles may be strengthened.
Steering arms may be modified for bump steer correction.
Aftermarket power steering pump allowed.
Brake air ducts allowed.
Brake hats allowed.
SHOCKS, SPRINGS and STRUTS:
steel bodied shock or strut per wheel, must be mounted in factory location.
Rubber grommet type shock mounting style may be replaced with heim joint.
Aftermarket racing shocks allowed. No aluminum bodied shocks.
re- valveable or Schrader valve type with external reservoir.
Strut type can be adjustable and/or replaceable cartridge- in- housing
aftermarket coil spring allowed. Rates optional. Spring dimensions are
least one end of springs and shocks must be in OEM location.
heights are measured with the driver in race trim.
Front spoiler minimum of 4 inches.
Center of the crankshaft bolt to the ground, minimum of ten (10) inches.
Frame height minimum of four (4) inches, measured at the frame rail.
Outer rocker panels minimum of (4) inches.
cell and or fuel cell frame: minimum eight (8) inches from lowest point.
pan minimum of four (4)inches.
WHEELS AND WHEEL SPACERS:
inch maximum width with minimum of 2 inch backspace.
Thirteen inch diameter only.
wheel stud diameter and length.
Offsets on all 4 wheels do not have to match.
pressure relief valves.
use any size, type or arrangement of wheel spacers to make ride width
1. TRACK TIRE ONLY.
2. Tires to be purchased from CPR or have CPR
branding to compete.
3. 13Ē Hoosier 790ís, 22.5 or 23.0 diameter only.
4. Dry Tire Rule ONLY.
5. NO tire treatment of
any kind permitted
6. NO Camber Cutting or
Grooving or any cutting.
7. May buy 4 tires to
start the season with before the 1st or 2nd race
only. 2 per race thereafter.
8.† You can only use
your tires in your database to compete with MANDATORY.
9. The driver is responsible for competing with the correct
10. If you compete on other than your
tires, your result will be a total DQ, loss of points, money and or fines
driver is responsible & must purchase the tires ONLY