THUNDER MOUNTAIN SPEEDWAY

BONE STOCK MINI RULES

Updated:  Wednesday March 10, 2010

(Clarifications in red)

The rules set forth herein are designed to provide fair parameters for competition and a high level of safety. NO expressed or implied warranty of safety shall result from publications of or compliance with these rules and regulations, they are intended as a guide for the conduct of sport and are no way a guarantee against injury or death to a participant, spectator or official. Driver/ Car owner is legally responsible for all crew signed in under car.

It is the Driver/ Car owners' responsibility to ensure his or her car is legal, if there is a question about the rules, email or phone tech committee before you show up, non conforming cars will not be allowed to run except for minor variations. Tires and Safety rules are only subjected to review by Tech only.

Refer to the safety rules for the basic building rules (Roll cage, Bumpers, Fuel cell, Approved clothing, etc.)

The emphasis is on keeping this class of cars inexpensive to build as well as providing for the safety and fun of the participants.  All cars will be extensively inspected for both safety and STOCK COMPONENTS.  Failure to follow the intent of the rules or class will result in disqualification of a car and or driver from the class.  Cars must be stock in every aspect with the following exceptions.  When the word “stock” is used it means as it came from the factory for the particular year and model in question.  This also includes replacement parts by part number.  Any question on parts need to be directed to the Board of Directors.

BODY SPECIFICATIONS

1.    Any four-passenger sedan produced with a 2.5 litre engine or smaller.  No sport cars.

2.    Body shape must remain stock.

3.    Lexan rear windows or quarter windows allowed.

4.    No four wheel drive vehicles.

SUSPENSION:

1.    All suspension components must remain stock to make and model of car.

2.    All pivot points and mounting points must remain in stock location.

3.    Springs must remain stock, no spacers allowed, no aftermarket springs or shocks allowed.

4.    Shock must remain in stock location

5.    May modify mounting point on upper right front strut tower ONLY for camber adjustment.  Maximum 2” negative camber allowed.  NO REAR CAMBER ALLOWED. 

IGNITION:

1.    Must have stock points or stock electronic ignition only.

2.    No aftermarket or high performance coils allowed including any spark enhancers.

3.    Single kill switch required to both disable the ignition and electric fuel pumps on fuel-injected cars. All switches to be clearly marked.

4.    Ignition and fuel pump also to be connected to fuel pressure reduced sending switch mount on rail or in fuel line (inertia switch for roll over in Fords may be accepted).

EXHAUST:

1.    Stock exhaust manifolds only.  Exhaust maximum 2” OD tube.

2.    Exhaust to exit behind driver.

3.    Muffler required.

TRANSMISSION:

1.    Any stock auto or standard transmission for make and model of car.

2.    Only stock flywheel and clutch to be used for make and model of car.

3.    Only stock torque converters allowed, transmission coolers allowed but must be mounted away from drivers compartment.

BODY STRIPPING RULES:

No metal to be removed inside car.

1.    Front doors may be gutted for three bar clearance into the doors.

FUEL TANK OR CELL:

1.    Approved gas tank (fuel cell recommended).

2.    Fuel tank mounted in truck, fuel cell to be above trunk floor but may be mounted in spare tire well.

3.    Stock fuel tanks may remain in car with the following conditions:

                                                  i.    Tank is plastic and situated in front of rear axle.

                                                 ii.    Aluminum skid plate to be mounted underneath and cover entire fuel tank.

                                                iii.    Gas caps to be tethered and marked with car number.

REAR END RULES:

1.    Any gear ratio allowed.

2.    Rear end and transaxle must remain stock to make and model of car.

3.    No positrack or welded rear ends allowed.

BRAKES:

1.    All brakes must be in working order.

2.    No aftermarket brake bias allowed.

3.    All brakes must be stock to make and model of car.

TIRES:

1.    Only 65 series or larger street legal tires allowed, no NuTreads or any other racing tires allowed.

2.    Maximum of 7” rim width.  Stock rims only.

3.    All tires to be either 13” or 14”, no mixing of tires.

4.    Wheels and tires not to protrude past fenders.

ENGINE RULES:

1.    Must be make to make, no Rotary engines.

2.    Fuel injection allowed (STOCK ONLY).

3.    Any push rod or single overhead cam type engine allowed.

4.    All engine components must remain stock – only OEM replacement parts allowed.

5.    Stock camshaft only, stock rods only for engine (no aftermarket rods allowed).

6.    Must use stock crank for that engine.

7.    No mixing or matching of parts to achieve any non-stock configuration.

8.    No decking of block.

CARBURETOR:

1.    Any stock make-to-make carburetor.

2.    Only single carburetors allowed.

3.    No performance carburetors allowed.

4.    No air boxes allowed.

INTAKE MANIFOLD:

1.    Must be stock intake, no machining or grinding allowed, no adapters or spacer plates allowed.