THUNDER MOUNTAIN SPEEDWAY

STREET STOCK RULES: 2012

Updated: March  2012

(New changes in red)

1. BODY
A.  Any North American built, stock production car through the current year. No full size trucks. Body, motor and chassis must be of the same manufacturer (altered with penalty).

B.  Minimum wheelbase 108 inches. Wheelbase must remain stock to the year and model with a maximum variation of one inch from the right side to the left side. The wheelbase must remain original to frame.
C.  Newer style body, skin only, may be used on older style chassis. You may swap a 1984 Monte Carlo body skin onto a 1969 Chevelle chassis or vice versa. Donor bodies to conform to minimum 108” wheelbase rule. Fenders extend, not the frame. The installation must be done safely and neatly. Complete shell may only be used if stock firewall mounts fit. Body must be complete and remain neat in the  stock location. Stock appearing aftermarket steel bodies allowed.  No aluminum or fiberglass panels allowed unless the panel being replaced came that way stock from the factory (altered with penalty- composite bodies  add 100lbs and  lose 1% of left side weight allowed).Late model nose and tailpieces permitted. Front valance/spoiler to be a maximum of 6-inches in height as measured from the track surface to conform with the 6-inch ride height rule. There will be no variance allowed. If damaged during racing the valance/spoiler must be returned to the specified 6-inch measurement.
D.  Must retain stock sills, floors, firewalls, cowlings and doorposts.
E.  Inner bracing may be removed from stock hood and trunk panels. Lids must be securely fastened. Doors must be strapped or welded shut.
F.  Sharp objects must be removed. Fold over or duct tape any sharp or rough edges. Roll fender well edges under not out
G.  Cars must have bumpers and they must be strapped to the fenders and  quarter panels to prevent hooking. Bumpers must be attached to the fenders or quarter panels within the bodylines of the car. May be modified for safety.
H.  Spoilers must have radiused corners and be a max. of 6 inches high.
I.   All glass must be removed.
J.   No push bumpers.   NO RUB RAILS ALLOWED!!
K.  No soft tops, station wagons or front wheel drives.
L.  A damaged car will only be permitted to race that day before being repaired. All cars must be maintained so as to present a neat appearance.   Cars must be brightly painted. Color and number must be of high contrast. Drivers name must be on one side of the car.

2.INTERIOR
A.  The interior of the car must be stripped of all flammable material.
B.  The interior sheet metal may only be removed for ease of roll cage installation.
C.  No transmission coolers, transmission lines or fuel lines in the drivers’ compartment.
D.  Holes in floor and firewall must be sealed with minimum 20- gauge steel.

3. WINDSHIELD

A.  A full windshield, with minimum two straps or tubes inside.
B.  Outside, four strong tabs if glass windshield. If Lexan, mount with 3/16 inch rivets, 6 inch spacing max.
C.  Sealed to cowl at least is mandatory.

4. WEIGHT

A.  Weight will be a minimum 3200 lbs., including driver, coming off the track after main event. No allowance for fuel loss.
B.  Left weight rule is 55% with driver belted in.
C. 47% rear maximum.
D.  Lead ballast is allowed but must be securely fastened above the bottom of the frame. Ballast must be painted white and have the car number on it. Minimum two, ½ inch bolts.

FRAME AND SUSPENSIONS

1.  FRAME

A.  Minimum 6-inch ground clearance to bottom of frame rail.  Camaros measured at door sill.
B.  No shortening of the frame horns allowed. If rusted or damaged they may be replaced but they must be the same length and location and of equal gauge metal or greater. No alterations to the K member.
C.  Uni-body must have sub frames tied together with minimum 2 inch x 3 inch, .120 inch steel tubing.

2. SHOCKS

A.  One stock type shock absorber bolted in the stock location per wheel.
B.  No air adjustable or coil over shocks. QA-1’s allowed.

C. Shocks must have stock type bushings on both ends.

3. FRONT SUSPENSIONS

A.  Stock control arms and mounts, both upper and lower, must remain in stock location to year and model of frame. Rated springs may be used.
B.  No Heim joints. No jacking bolts allowed. No tall joints.
C.  No cutting, welding or bending of “A” arms.
D.  Cars must have a skid plate, minimum 2 ½ inches wide, under the right front lower control arm.
E.  The upper control arm shaft called the Problem Solver is allowed to attain camber on G.M. cars.
F.  O.E.M. or jobber cloned parts only.
G.  Stock front steering components, i.e. idler arms, steering box, tie rods, drag link, etc.!!!
H.  All part numbers must remain intact. Alteration or removal of part numbers will make that part illegal and the car subject to disqualification.

4. REAR SUSPENSIONS

A.  Stock upper trailing arms. Mounts may be re-drilled to allow for lengthening or shortening. All mountings subject to Tech. approval.
B.  No adjustable spring shackles or jacking bolts.
C.  Only a secured full circle rubber spacer on top and/or secured full circle metal spacer(s) at the bottom of coil springs.
D.  Lowering blocks allowed on leaf springs.

DRIVETRAIN

A.  Ford 9” rear end conversions are allowed, but the rear end must be centered in the stock frame. Shock angles to remain stock for the chassis, control arm angles must be stock. Altering of the mounting bracket length and location not allowed on installed rear end. All mountings subject to Technical approval.
B    Locked rear ends allowed. No Detroit Lockers or Gold Trac. No clutch or ratchet driven carriers.
C.  Drive shafts must have at least one U shaped retaining bracket installed near the front of the drive shaft.
D.  Drive shafts must be painted white or bright color.
E.  Any O.E.M. manual or automatic transmission is allowed but all must have a working reverse.
F.  Automatic transmissions must have a working torque converter.
G.  Cars with manual transmissions must have a 360-degree scatter shield that is racing approved.

WHEELS, TIRES AND BRAKES

A.  A heavy-duty steel wheel up to a maximum 8-inch rim width will be permitted.
B. Wheel weights must be stick on type installed on the inside of the rim with tape over them. No pound on weights allowed.
C.  The tire and wheel shall not be exposed more than 2 inches from the outside of the body as measured from the tire sidewall to the body.  No flaring allowed.
D.  American Racer G60 or P265 race tires allowed. Cars running the S.O.B. Street Series with new Goodyear tires are subject to a 100 lb. weight penalty (Agassiz only). Used Goodyears can run with no weight penalty (Agassiz only) if the tread depth is less than 5/32 of an inch.  No compound changes allowed, i.e. no tire softeners.
E.  Cars must have four stock wheel brakes in good working order.
F.  Brake pedal assembly must be in stock location. No aftermarket brake pedals. One, rear brake only, brake bias valve allowed. Must not be mounted within reach of the driver. No bleeders.
G.  No rear discs.

ENGINE – Introducing GM 602 Crate engine for 2010.  Western Speedwaycrate engine rules will apply for 2012. 
1.GENERAL
A.   Small block engines only. Maximum overbore is .060-inch
B.  G.M.            350 max. cid
C.  Chrysler       360 max. cid
D.  Ford             351 max. cid

E.  The engine and chassis must be of the same manufacturer (altered with penalty).
F.  The engine must be stock two-barrel specs. No Vortec.
G.  Cars must have a working starter.
H.  The engine must be in the stock forward location without altering the frame, with stock mounts in the stock location.
I.   Cast flat top pistons only. No forged pistons. G.M. must have 4 valve reliefs that are factory machined unless they have no valve relief such  as Chrysler 318, 360.
J.  No fuel injection. No big blocks. No Chrysler 340 cid. No G.M. 400 cid.
K.  No stroking allowed by matching crankshaft from one engine size to another, i.e. do not put a 350 Chev. Crank in a 400 block or vice versa.
L.  Any flat tappet, hydraulic or solid camshaft allowed as long as the 1.5  rocker ratio remains. No mushroom or roller cams.

2. CARBURETOR

A.  Any stock two-barrel carb on stock cast iron intake manifold. Removal of choke assembly is allowed. The choke horn stays.
B.  Air filter with metal lid is mandatory.
C.  One 4-inch diameter air duct is allowed.

3. HEADS

A.  Absolutely no modifications to heads such as porting, polishing, port matching, roller rockers or angle milling.
B.  Maximum 1.94 inch intake, 1.50 inch exhaust.
C.  Chrysler 318 two-barrel heads allowed. Ford 289 and 302 two barrel heads allowed. 305 G.M. heads allowed.
D.  G.M. Camel Bump heads.
E.  3/8 screw in studs allowed. No guide plates.

4. EXHAUST

A.  You must have stock cast iron manifolds.
B.  No alterations to manifolds allowed.
C.  No 2.5 inch Corvette center dumps. 2 inch are okay.
D.  Must have a muffler(s), maximum 95db at Tower and in the pits.
E.  Two-2 inch diameter exhaust pipes. Minimum of 24-inches in length, (i.e. 24-inches of exhaust pipe from the manifold). Must extend past the driver and be within 12-inches of the rear tires.
F.  System must end within 12 inches of rear tire(s).
G.  The pipes must not pass through the drivers’ compartment.

SAFETY
1.GENERAL

A.  Coolers must be ahead of the front firewall or behind the rear firewall.
B.  Radiator must be in front of engine and must have minimum 4 liter catch can.
C.  Cars must have a working 2-½ lb. fire extinguisher within easy reach of the driver.
D.  One stock sized rear view mirror inside the bodyline, one outside mirror allowed.

2. BATTERY

A.  Battery kill switch mandatory. Must be identified and on the left side of the car within easy reach of the Safety Personnel.
B.  Battery must be securely mounted and sealed in a metal box with a lid.  Locate outside of fuel compartment.

3. ROLL CAGE

A.  Roll cage required, minimum 8 points to chassis. It must be minimum 1 ¾ inch x .095 inch steel tubing. All main joints must be gusseted.
B.  Offset cages to be allowed but may be subject to a weight penalty.
C.  There must be a minimum of four door tubes on the drivers’ side parallel to the ground.
D.  At least four passenger side door tubes are required. A stock door with beam counts as one bar.
E.  A windshield bar and padded center roof bar must be installed.
F.  Main hoop must be cross-braced. Front uprights must have dash bar.
G.  Two cage tubes will be placed from the upper rear corners of the main hoop at the top of the cage, rearwards, to the frame members behind the fuel cell.
H.  One bar may be installed for radiator protection but must not protrude past the bumper.
I.   Cages will have an ankle bar on the left  and a bay bar system which links roll cage from right front frame rail to left rear shock tower.
J.   Roll cage members adjacent to the driver must be padded.
K.  Head clearance must be minimum 2 inches. More is better.
L.  Mandatory anti intrusion plates on driver’s door bars, minimum 1/8-inch steel plate. See cage diagrams for details.

M. All cages subject to tech. approval.

***See below for diagram of rollcage****

4. SEAT, BELTS AND WINDOW NET

A.  Cars must have a safety approved aluminum bucket seat mounted securely to the roll cage with a minimum of four 5/16” bolts, subject  to Tech. approval.
B.  Seats will have headrests supported by cage.
C.  Cars must have an approved harness mounted to the roll cage.
D.  Shoulder belts must be fastened below shoulder height.
E.  Belt certification is 8 years maximum.
F.  Drivers window must have an approved safety net with a quick release catch at the top. Mount with minimum 3/8-inch diameter unthreaded steel rod, top and bottom.

5. FUEL CELL

A.  Fuel cells are mandatory. Cells must be equipped with foam.
B.  Fuel cells must be mounted between the frame rails and as far forward as possible and practical. Fuel cell must be in a metal case and have a minimum 8-inch ground clearance.
C.  If tank hangs below frame, a nerf bar must protect it.
D.  The overflow must extend below fuel cell.
E.  No electric fuel pumps. No alcohol racing fuel.
F.  A ground strap from the filler neck flange to the frame is mandatory.