Macon Speedway will use the UMP DIRTcar Pro Modified rules located at http://www.dirtcarump.com/rules/dirtcar-ump-pro-modified-rules/ with the following amendments.
G.) This means that no aftermarket parks are allowed, i.e.: Crane, Comp, etc. GM HEI Distrubutors only on crate engines.
H.) 2. Chevrolet limited to 350 stock OEM block. No 400 blocks.
4. In 2015, roller rocker arms will be allowed.
No Holley 4412 HP carburetors allowed
No Tri-Y Headers allowed.
E.) All cars must weigh 2400 lbs at all times with driver.
15.5 Fuel Cells and Fuel
E.) E-85 will also be permitted.
B.) Quick change rear ends will be permitted. Only magnetic steel tubes will be permitted. Drivers with quick change rear ends must declare gear ratio when signing in. Subject to inspection at anytime. Drivers found to have a different gear than what they declared will be disqualified.
15.7.1 Rear Suspension
B.) Springs may be mounted on either side of rearend.
H.) Coilover shocks on the front suspension will not be permitted. Chains, cables and/or tethers to limit or control movement will be permitted.
J.) Steel shocks only. No schrader valves or other type of adjustable shocks permitted. No aluminum tops or bottoms on shocks (all steel). Entire shock must be the same diameter.
15.8 – Wheels and Tires
B.) The DIRTcar approved tire is the Hoosier A-40, A-40S or H-40 26.5/8.0/15 or 27.5/8.0/15. The maximum width of the tire will be 9” inches.
C.) Siping will be permitted. Recapping of an approved tire is not permitted. Grooving is not permitted (2015 burn off as announced). Burn off is as follows: Grooved tires allowed on rear thru May 31st. Grooved tires allowed on front thru the end of the 2015 racing season.