2015 Linda's Speedway 125 Rules
i) Car and driver weight at completion of race shall be 600 pounds or greater
i) Single cylinder engines only are allowed for all classes
ii) Maximum piston displacements shall be
(a) 8.24 cu.in. (or 135.00cc) for 125 cars
(b) 4-stroke 250 engine - Stock bore and stroke. Any work on heads and valves is allowed. The existing modified (4 Stroke 270 engines) engine owners may run with 125cc class; Fuel injection is permitted, if fuel injection is used, the motor must remain stock bore and stroke and have OEM throttle bodies.
iii) Titanium cranks are illegal. (Protest able only)
iv) To find cubic centimeters (cc) multiply Bore X Bore (mm) x3.14 x stroke (mm) divide by 4000.
i) Mufflers are required to provide a sound limit of 100 dba maximum
ii) 4-2stroke must provide muffler at sound limit of 104 dba maximum
i) No open drive shafts will be allowed.
ii) Chain guards must be installed on all cars where chains are exposed to the driver.
5) CAR DIMENSIONS
i) Wheelbase- 70 inches, maximum – 56 inches, minimum
ii) Width (at tire sidewalls) 60 inches maximum, 40 inches minimum.
iii) Roll cages
(a) Roll cages are mandatory
(b) There must be a minimum 12 inches opening between the top rails:
(c) The material must be a minimum of one inch O.D., .083-inch wall thickness: anything 1.25 inch O.D. and over .065.
6) WHEELS, TIRES AND BRAKES
i) Wheel diameter: 10 inch maximum
ii) All cars must be equipped with functional rear brakes. Front brakes are optional.
i) All cars must have complete bodies (normal sprint car). No extending panels on hood or tail.
Painting and numbering
(a) A 10 inch minimum car number is to be painted on both sides of the wing.
(b) Any letter as part of the number must be readable
(a) All cars must be equipped with a firewall between the driver and the engine compartment. Minimum thickness specs are: Steel 24 gauge (0.0239 inches), Aluminum 0.050 inches,
Fiberglass or plastic 0.095 inches.
iii) Floor pan
(a) The floor pan must come to a point just rear of the front axle or tie rod to the front edge of the driver’s seat.
i) All wings must be all metal or lexan construction externally B. All mounts and adjustments must be outside of roll cage C. Wings sizes:
(a) Wings cannot exceed 12 sq. ft. (1728 sq. in.) this will include all flat or tapered areas viewable from the top.
(b) Maximum length of wing panel is 54 inches.
(c) A front wing is optional, not to exceed 2.5 sq. ft. (360 sq. in.)