2012 X-Modified Rules and Regulations
Section I: General Requirements.
A. Any Engine Part, all frame and suspension components will be steel, unless noted. No titanium or drilled attachment components. 1960 or newer full passenger car frame, may be cut off 36” (inches) in front of center of rear axle.
B. Frames will maintain original dimensions and remain intact except notched for radiator placement, weight jack, spring clearance and mounting tabs. Maximum 2”x4” lower frame may join rear suspension. No portion will be less than 4” from ground except pan and front cross member.
C. 108” wheelbase minimum, with a maximum width of no more than 78” outside tires.
D. Continuous roll cage, halo, and halo support will be of a minimum of 1.501”x .095” steel tubing. Must have one cross bar in halo. This configuration will be attached to main frame in 6 places. Drivers head will be below the halo while seated, three inches recommended.
E. Three door bars will be 1.5” x .095, welded to front and rear uprights, with vertical supports. Must have at least one 1.25” right side cage bar angled or horizontal. Recommend door plates .049” drivers side from top door bar to bottom door bar, Rear post to 5” in front of seat.
F. Rub rail, vertical bar, or rear engine support will be added for foot protection.
G. Must have .250” x 2” plate or 1” x .095” tubing drive shaft hoop, welded 6” behind front of drive shaft.
H. No cage bars will protrude thru hood. Main cage will be behind rear of engine.
I. Will have a minimum of three .250” window bars in front of driver.
J. Two bar front bumpers 1.25x.065 minimum required. Front bumper should be mounted from frame-end to frame-end with the bottom loop parallel to ground. Lower bar will be no lower than lowest part of front frame horn and no wider than 1.5” on each side. Upper bar directly above lower bar.
K. Nerf irons will not be wider than outside of rear tires, may not contain any sharp edges.
L. Rear bumpers can be strait, looped or turned forward. Forward turned bumpers can be no wider than 2” outside the rear tires, must be made of continuous hoops. All bumpers must protect fuel cell and line up with front bumpers. Strait bumpers must be no wider than 5” wider than outside rear frame rails. A looped bumper can extend to the body panels.
M. The centers of front and rear bumpers will be 18” high + or – 2”.
N. 32 gallon fuel cell maximum with roll over valve. Must be mounted between rear frame rails and behind rear axle. Dimensions of 6” above ground, 4” in front of bumper. Must be mounted securely, in steel box, with 2” straps encircling entire cell. No bottom fuel pickups. One fuel filter maximum. Lower portion of rear bumper will protect full cell. Gasoline only.
O. All ballast will be mounted with two ½” inch diameter bolts, outside driver box, and painted white. All cars will weigh 2300 lbs minimum.
Section II: Engine, Transmission, Drive Shaft.
A. 360 cubic inch displacement or less. Compression of 9.5 or less. 1% error.
B. Stock type, stamped rocker arms only. No roller tip rocker arms.
C. Screw-in rocker arm studs are ok. 3/8 studs only with guide plates. No stud girdles of any kind.
D. Polly locks are okay.
E. Must have cast iron two-barrel intake. No acid dipping, no pressure porting, The depth of the plenum will be measured. Deep side- 3.950” max, Short side- 2.030”. We expect to see an unmodified runner to the back of the divider, with ribs that stand up .150”. We will use a caliper to measure bores and depth. If your manifold measures noticeably large, you must show us more than one manifold that is the same. An unaltered marine cast iron two-barrel intake will be allowed with Vortec heads. You can be disqualified or asked to race with a different manifold. USA Raceway reserves the right to exchange intake manifolds after a competitors or vehicles second main event win in a single point season. (See Section VI, Rule F)
F. If intake found to be illegal will loose all prize money for that night and points for that season.
G. Flat tappet camshafts only. No roller lifters.
H. Aluminum water pumps & pulleys are allowed.
I. After-market power steering pumps are allowed.
J. Must have cast iron cylinder heads, original valve angle and location.
K. HEI ignition systems only. Must have the large cap with coil in cap. All X-Mods will be required to use a MSD Soft Touch rev limiter with a 7,000 rpm chip. MSD makes soft touch for Chevy, Ford and Mopar. Chip must be out of reach of driver.
L. Valve springs: 1.250 maximum diameter, .195” wire, steel retainers, 5 full coils.
M. Crankshafts cannot weigh less than 49lbs. Must install a 1” diameter pipe plug to inspect crankshaft, or remove pan.
N. No titanium anywhere.
O. Tachometer may be claimed for $300 by promoter and lead lap drivers.
P. Exhaust system must be mounted in such a way as to direct spent gasses away from cockpit of vehicle and away from areas of possible fuel spillage. No Tri-Y headers allowed. All exhaust must go through headers. Mufflers are mandatory. 95 db max.
A. All cars must run an OEM two barrel Rochester carburetor. Must maintain the integrity and intent of original manufacturing. (Example: modifying carburetor to allow use of Holley jets is allowed, modifying carburetor in order to add additional jets is not allowed) No Holley carburetors or adapter plates allowed, no four-barrel manifolds allowed, no spacer plate, 1 stock OEM carburetor gasket no more than ¼” thick under throttle plates. Throttle bore can be no larger than 1-11/16”. Throttle butterfly size will be no more than 1.725” and it must have sharp corner at the bottom of the bores, no modification at this point. USA Raceway reserves the right to exchange Carburetor after a competitors or vehicles third main event win single point season. (See Section VI, Rule F)
A. Car must move forward and back with engine running. Will not allow quick change gearing or close ratio transmissions. Bert or Brinn okay. No magnesium
B. Scatter proof bell housing required on cars with light weight flex plates, single clutch disc and full pressure plates.
C. Single ratio passenger car or pickup rear axles. Recommend floated hubs. Aluminum lowering blocks, drive plates, and axle caps allowed. One inch inspection hole in rear axle gear cover recommended. Locked rear axles only. No C-Clip rearends allowed
D. No electronic engine adjustment devices. No wheel speed engine interface, no traction control. No brake engine electronics.
Section III: Suspension, Wheels & Tires
A. Unaltered OEM front spindle, lower A-arm, Drag link, inner tie rod ends, steering box, idler arm and pitman arm, sway bar. Steering box must remain in original bolt circle position. No rack and pinion systems. May weld shock mount on lower control arm. Weight jack will be centered in A-arm spring location.
B. May use fabricated upper A-arm with heim joint pivots, steel or aluminum cross shaft. Outer tie rod and tie rod sleeve can be replaced with .625” rod ends and sleeve tubing. May use bump steer spacer on outside of rod ends.
C. Steering and driver position will be on the left side of the driveline.
D. Any steel shock that retails for $140 or less. Coil or leaf spring allowed. Coil springs will be at least 4.5” outer diameter and unaltered from the original manufactured purpose (No cutting, welding, heating, ect.). No torsion bars, air bags, or pressurized springs. One spring and 1 shock absorber per wheel. Four shock absorbers total. No adjustable or canister shocks allowed.
E. No wheelbase or weight jacking devices allowed in driver’s compartment.
F. Three link or leaf springs, or factory four link, with two upper arms only. All links will be solid, heim rods. Lower arms will be the same length no shorter than 16”. The panhard bar will be a minimum of 19”. Must be solid pull bar with heims, no biscuits or springs. Brake floaters are not allowed.
G. Four wheel brakes at all times. Adjustable from front to rear only.
H. Ford, Chevy, Chrysler parts can be mixed and mounted for use. Brake calipers must be 100% unaltered.
I. No solid, drilled, scalloped, or lightened rotors.
Wheels & Tires
A. All wheels will be 8” wide, measured on the outside of the mounted tire bead. One bead lock and mud plug allowed on right rear position. No inner mud shields.
B. Tires: American Racer KK704 or Hoosier G60 Stamped or Unstamped Allowed.(Hoosier DCM400 allowed until June 1, 2011) Tire can be de-glazed with sanding pads or grinding discs. Re-grooving and siping ok.
Section IV – Safety
A. Helmets will be SA 2000 or newer.
B. Drivers will have SFI approved, fireproof: gloves, shoes, and double layer suit.
C. Window net or arm restraints required.
D. A five point seat belt system, properly mounted to cage. 3 years old max.
E. Halo and other interior tubing will be padded.
F. Raceceiver Radios are mandatory; we reserve the right to penalize drivers that don’t run a Raceceiver. No two way radios will be allowed. No other communication devices allowed.
Section V – Bodies
A. .125” aluminum or.060 steel floor recommended.
Fully enclosed cockpit, with cowling the same width can not extend past steering wheel.
B. Bodies can be made of steel or aluminum. Fiberglass roofs ok.
C. Front, rear, and side windows will resemble OEM production.
D. No mirrors allowed.
E. Nose piece can be no wider than front stub and stop at radiator.
F. May run side panels on nose piece. 2” above nose plate and to bottom of front stub.
G. Hood can be no wider that front stub, have a maximum slope of 3”. No dish or reverse rake hoods.
H. Air filter protector can be no taller than 6”
I. Deck will be 66” wide and 120” long maximum, parallel with frame, and maximum slope of 6” front to rear. Half way uses up 50% of available slope.
J. Deck can extend 46” past center of rear axle. Rear of deck will be a maximum of 38” from ground.
K. May slope deck for driver escape. Must be parallel with deck and use 90 degree turns if sloped more than 2”.
L. Roof may slope down at the front 5”. May be lower at the rear 2” maximum, and be 52” wide and 56” long maximum.
M. Roof may be turned down a maximum of ½” for support at the rear.
N. Side window height will be 12” to 18” in height on both sides.
O. Front roof supports can be no longer than 20” and go no farther forward than front of door.
P. Rear roof sail panels must slope gradually to 5” maximum at rear and the same on both sides.
Q. Fins, wings, or spoilers are not allowed.
R. Top of door must be 72” from center of rear axle to motor plate. It can slope forward 8” at the bottom forward portion. The height will be a minimum of 22” tall to 30” max.
S. May use a maximum of 6” plastic at the bottom of doors. Must maintain 3” height above ground.
T. One rear tire must be visible looking down on the car
U. Cars will have a 20” tall and 4” wide numbers on the top and both sides. A number on the right side, rear panel is required.
Section VI – Protest Rules
A. If track officials request random tear down of engine, racer will remove valve covers, intake, and heads for inspection at the time of request. If engine is determined LEGAL racer will be supplied with stock gaskets to reassemble engine. If engine is ILLEGAL racer will loose all monies and all points for that night.
B. A protest fee of $125.00 dollars will be collected by track officials before a protest is official. If racer is ILLEGAL see rule “A”, funds will be deposited in point’s fund. Protest must be filed within 15 minutes of the posted finish of that division’s main event.
C. ENGINE CAN BE TORN DOWN AT ANYTIME. You will remove valve covers, intake manifold, exhaust manifold and heads; you will keep tools to perform this task. No grace race on cubic inches (max 360 ci).
D. Failure to comply will result in but not limited to disqualification, loss of monies, points for the night, loss of points accumulated to that point. If you are found legal, the track will provide gaskets to reassemble.
E. If these rules do not clearly say you can, assume that you cannot.
F. In the instance of a multiple day event certain exceptions may be made or delayed, including but not limited to, certain protests, routine engine tear down and/or part exchange procedures.