Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
Australian Off Road Championship (AORC) is an off-road racing championship held annually in Australia, with the inaugural event held in 1981. AORC events are defined as ‘long course’ events that are conducted on a track of no less than 15 kilometres in length, but are usually between 75 and 100 kilometres. The courses and tracks used for the AORC vary greatly and can be narrow, twisting and tree-lined, undulating farmland tracks, sand dunes and creek crossings, often incorporating man-made jumps and other obstacles but usually have high average speeds.
Most events run over three days with Scrutineering (safety checks on vehicles), Prologue (short time trial to determine starting order for event proper) and racing over one to two days (usually split into Sections). Most events also feature a Top Ten Shootout (opportunity for the ten fastest prologue vehicles to prologue again) and a Dash for Cash where the fastest two vehicles in each class (not involved in the Top Ten Shootout) race each other to win prize money.
One or two seat buggy up to 6.0 litre naturally aspirated engine or up to 3.5 litre turbo engine.
Prolite buggy
101–199
One or two seat buggy up to 3.5 litre naturally aspirated engine.
Super 1650 buggy
201–299
Two seat buggy between 1.3 and 1.65 litre naturally aspirated engine.
Sportsman buggy
301–399
Two seat buggy up to 1.3 litre naturally aspirated engine. No longer recognised as a class at AORC level – these vehicles must run in Super 1650.
Extreme 2WD
401–499
One or two seat 'truck' up to 6.0 litre naturally aspirated engine or up to 3.5 litre turbo engine. Vehicle is otherwise unlimited in design and construction except it must somewhat resemble a registerable vehicle. Volkswagen Baja vehicles are included in this class.
Performance 2WD
501–599
Two seat vehicle based on a production vehicle with only moderate modifications permitted.
Superlite A
601–699
Two seat side by side recreational vehicle up to 1.2 litre naturally aspirated engine. Minor modifications only permitted.
Superlite B
601–699
Two seat side by side recreational vehicle up to 1.2 litre turbo engine. Minor modifications only permitted.
Production 4WD
701–799
Production 4WD permitting minor modifications only.
Extreme 4WD
801–899
Highly modified 4WD similar to Extreme 2WD
Sportslite
1001–1099
One or two seat buggy up to 2.5 litre naturally aspirated engine or 1.6 litre turbo engine. New class – not recognised at AORC level in 2017.