Chapter (3) Suspension rules in SAE

3.1 GENERAL CHASSIS RULES

which demonstrate handling inappropriate for an autocross circuit. travel of at least

50.8 mm (2 inches), 25.4 mm (1 inch) jounce and The judges reserve the right to

disqualify cars which do not The car must be equipped with a fully operational

suspension System with shock absorbers, front and rear, with usable wheel

represent a serious attempt at an operational suspension system or Inspection,

either by direct view or by removing any covers. All suspension mounting points

must be visible at Technical 25.4 mm (1inch) rebound, with driver seated.

3.2 Wheelbase

The car must have a wheelbase of at least 1525 mm (60 inches). The

wheelbase is measured from the center of ground contact of the front

and rear tires with the wheels pointed straight ahead.

3.3 Vehicle Track

The smaller track of the vehicle (front or rear) must be no less than 75%

of the larger track.

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3.4 Ground Clearance

The ground clearance must be sufficient to prevent any portion of

the car (other than tires) from touching the ground during track

events, and with the driver aboard there must be a minimum of

25.4 mm (1 inch) of static ground clearance under the complete car

at all times.

3.5 Wheels

 The wheels of the car must be 203.2 mm (8.0 inches) or more in

diameter

 Any wheel mounting system that uses a single retaining nut must

incorporate a device to retain the nut and the wheel in the event that

the nut loosens

3.6 Tires

Vehicles may have two types of tires as follows:

3.6.1 Dry Tires

The tires on the vehicle when it is presented for technical

inspection are defined as its “Dry Tires”.

The dry tires may be any size or type. They may be slicks or

treaded.

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3.6.2 Rain Tires

Rain tires may be any size or type of treaded or grooved tire provided:

The tread pattern or grooves were molded in by the tire manufacturer, or

were cut by the tire manufacturer or his appointed agent. Any grooves

that have been cut must have documentary proof that it was done in

accordance with these rules. There is a minimum tread depth of 2.4 mms

(3/32 inch). Note: Hand cutting, grooving or modification of the tires by

the teams is specifically prohibited. Within each tire set, the tire

compound or size, or wheel type or size may not be changed after static

judging has begun. Tire warmers are not allowed. No traction enhancers

may be applied to the tires after the static judging has begun.

3.7 Rollover Stability

The track and center of gravity of the car must combine to provide

adequate rollover stability. Rollover stability will be evaluated on a tilt

table using a pass/fail test. The vehicle must not roll when tilted at an

angle of sixty degree (60°) to the horizontal in either direction,

corresponding to 1.7 G’s. The tilt test will be conducted with the tallest

driver in the normal driving position.

3.8 Securing Fasteners

All critical bolt, nuts, and other fasteners on the steering, braking,

driver’s harness, and suspension must be secured from unintentional

loosening by the use of positive locking mechanisms.

Positive locking mechanisms include:

• Correctly installed safety wiring

• Cotter pins

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• Nylon lock nuts

• Prevailing torque lock nuts

Note:

ock washers and thread locking compounds, e.g. Loctite®, DO NOT

meet the positive locking

3.9.1 requirement

There must be a minimum of two (2) full threads projecting from any

lock nut. All spherical rod ends and spherical bearings on the steering or

suspension must be in double shear or captured by having a screw/bolt

head or washer with an O.D. that is larger than spherical bearing housing

I.D