Eleven people have so far been arrested at the Bathurst 1000 for drug, offensive conduct and driving offences.
Police allege one person had a small quantity of cannabis hidden in the fuse box of his car.
About 600 police officers will be deployed at Mount Panorama this weekend as part of Operation Mountaineer to curb illegal activity during the V8 motorcar event.
"We will be searching cars as they enter and any dangerous or illegal items will be seized by police, and, where appropriate, those in possession of illegal items, drugs or weapons will be charged," Assistant Commissioner Lee Shearer said in a statement.
Police will also enforce the one case of beer per person per day rule, he said.
The restriction equates to one case of full-strength beer, 36 cans of light or mid-strength beer, one case of pre-mixed drinks or up to four litres of wine.
More than 160 people were arrested at last year's Bathurst 1000 for offences including supplying or possessing prohibited drugs, possessing weapons and fireworks, malicious damage, offensive behaviour, drink driving and speeding.
Police have urged those travelling to the event this weekend to take care and expect delays as vehicles are searched before entering the mountain.