2017 CRATEUSA MODZ RULES
01. Basic IMCA and Seca body rules. GM 602 engine. Rear of engine bell housing flange at least 72” forward from
the center of
rear axle. Engine offset within 2” of center line of front cross member. Minimum engine height 11” from
front center of crankshaft to ground. No rear spoiler.
02. Standard type roll cage not less than 1.5” outside diameter and wall thickness of at least .095.
04. Exhaust headers parallel to ground. No TriY or merge headers.
05. Factory production US car Frames complete in front of firewall.
06. Frames may not be widened or narrowed. Front cross member may be notched for radiator clearance.
Minimum frame & body height from ground is 4”.
07. Front O.E.M. suspension in stock location. Must be replaceable by stock part from same type suspension.
No aluminum suspension parts. Stock passenger car spindles only. No fabricated spindles. Bottom A-frames
may not be altered or moved. Control arms copies may be used that are approved. Bump Stops on right front only
08. Tubular type upper A-frame allowed and may be relocated.
09. Rear of frame may be altered to accept leaf or coil springs. Any coil springs must be at least 4 1/2” outside
diameter. No fiberglass springs. No fiberglass lift bars. No rear torsion bars
10. SHOCKS: One steel, nonadjustable, unaltered shock per wheel. All shocks must collapse completely. One
additional shock allowed in pull-bar area. No external or internal bumpers or stops. No threaded body, front
coil-over, air, or remote reservoir shocks. No Schrader or bladder type valve allowed. Front half may be
shielded. One or all shocks may be claimed per event for $100.00each. Claimer may choose which
shock(s) to be claimed.
11. No lay down shocks less than 12” from brake rotor.
12. Wheelbase: Minimum 108”, Maximum 112”. No front clips or tube type allowed.
No aluminum suspension or rear-end parts. No aluminum or fiberglass drive shafts. Steel only.
13. With a level, roof centerline must have no more than 2" clearance at rear and no more than 5" at front. Sail
panel from roof to body, maximum bow 4". Sail panel front to rear 1" maximum curve at center. Go to
www.IMCA.com for Modified body photo. No wings. No ground effects allowed inside or outside of car.
14. Engine compartment open. No side panels. Hood sides maximum 4” drop and enclosed at rear of hood.
Bodies may extend no further forward than back of block. allowed. Rear panel may be open from quarter
panel to quarter panel. No spoilers or spoiler sides.
15. No direct drives. Must be able to shift to forward/reverse with engine running. BERT type trans OK.
16. No adjustable shocks, hydraulic or pneumatic weight jacks, Trackers, M.S.D. boxes or similar adjustable
components of any kind inside cockpit of car. No traction control devices.
17. Front bumper (min. 1.5”) mounted frame end to frame end with bottom loop parallel to ground. Late model
type rear bumper OK. Must protect fuel cell. Center of bumpers (front and rear) 18” from ground.
(Tolerance 2”) rear bumper, nerf bars & bodies not past width of rear tires. No sharp edges.
18. Rear roof support not past front side of rear upright of roll bar.
19. Firewall solid from left side door to cockpit. No gaps. No holes.
20. One carburetor. 1 inch spacer. (No Tolerance). Spacer may not intrude into carb or intake. One gasket per
surface. 0.070" maximum each. No electric fuel pumps. No magnetos.
21. No high volume oil pumps.
22. Pump gas,E85,or Track fuel only. No alcohol, no nitrous oxide, nitrous methane, propylene oxide or any type
of additives are permitted. Fuel may be checked at any time.
23. Any passenger car type rear end may be used. No aluminum allowed, except lowering blocks, axle cap and
drive plate. Any truck rear end OK. Quick change OK, no weight penalty. (May require spec gear ratios).
24. O.E.M Steering box with original bolt pattern for type of frame used. No center steering. No rack/pinion.
25. Power steering belts must be mounted in front of engine.
26. No aluminum shells, hubs, “A” frames, spindles or any other aluminum suspension parts. No plastic or
carbon wheels. All calipers O.E.M. No machining or lightening of caliper.
27. Minimum weight with driver 2,400 lbs.25 lb weight break with approved Head, Neck Restraint system
28. Tires..HOOSIER G60 (IMCA OR OPEN) AND AMERICAN RACER KK704 ......Also the American racer HARD
(Available only at prankster racing products & Heintz performance ) No grooving,siping,or soaking Must stay
29. Steel racing wheels maximum 8”, bead lock right side only.
30. Maximum overall width (front or rear) 78” from outside of tread to outside of tread. wheel. Maximum 1”
steel or aluminum spacer allowed on front only.
Any protest items not specifically covered below are considered track protest items, track protest rules will apply
(this does include Claimable items).
1-Complete engine teardown: $1000 ($200 acceptance fee) - Engine will be impounded and checked by certified
builder. $200 to the builder, $200 to the track $800 to the winner of the protest.
Non Sealed (engines that have been unsealed, not resealed by certified builder) $700 ($300 acceptance fee)-
Engine will be impounded and checked by a certified builder ($200 to builder- $200 to the track $600 to winner of
the protest). Crankshaft, ,Clutch, Flywheel. Engine seal bolts not required but must meet all criteria as per GM specs
(check with Tech on exemptions). Seal bolts do not make an engine legal. Engine Claim $3,400.00
32. 602 replacement parts allowed other than GM:
Pistons; Federal Mogal/Sealed power/Speed Pro replacement piston H815ACP
Rings; Hastings 2M486 Hydraulic lifter; HT817
Valves; Manley stock replacement, no undercut stems, no stainless.
Bearings; mains,rods,cam: Clevite P series bearings or equivalent, no performance type, no H type,
no coated etc. Durabond cam bearings
GM gaskets, made by Victor Reinz, .028 head gasket thickness.
33. All drivers must fill out entry/license application & go through tech prior to competing.
34. Tech inspection and Tech decal does not imply or certify that the race car is safe or meets all of the rules.
Drivers, car owners and crew are responsible for the safety, operation and rule compliance of the race car
at all times. Tech inspection will not prevent death, serious injury or property damage. By entering the
premises, all participants (includes anyone in restricted area) have agreed to abide by all rules, regulations
and decisions by officials.
35. Read Track saftey rules that are applicable to division. Fire retardant driving suit & gloves are required.
36. No Mirrors. No Radios. RACEceivers & all Safety Equipment required any time you are on the track!
.$125 tire protest rule...
If caught altering a tire from untouched will result in .
1st time 2 RACE suspension & $500 fine,lose all points to date.
2nd time $2500 fine and suspension for 365 days
If you get caught cheating within the bolts/seals
All parts (illegal) will destroyed by (Crateusa officials)
Driver/car owner will be suspended for 365 days and $5000 fine before you will be allowed to compete in any
Caught cheating outside bolts/seals .
Lose all points to date, $250 fine 2 race suspension.