Queensland's recent wet weather and the unforgiving concrete walls of the Surfers Paradise street circuit are an ominous mix for Supercars championship challenger Jamie Whincup.

The Holden ace starts this weekend's Gold Coast 600 trailing Ford's Fabian Coulthard by 91 points, as the championship's endurance season reaches its climax.

Three other drivers, Ford pair Scott McLaughlin and Chaz Mostert and Whincup's teammate Shane Van Gisbergen are also firmly in the title race in one of the most open Supercars seasons in years.

Heavy rain has lashed the Gold Coast for most of the week and more wet weather is forecast for the weekend, particularly on Saturday.

With the 2.96km Gold Coast circuit offering little sympathy for drivers who come unstuck, Whincup knows only too well he or one of his title rivals could find themselves jeopardising their championship hopes with a mistake.

"It's already a concrete canyon of a circuit," Whincup said.

"Throwing in wet weather conditions means whoever is standing on the podium is going to have worked hard for it."

No one has won more than Whincup's eight race victories on the Gold Coast. while he has six pole positions at Surfers - also a record tally.

Championship leader Coulthard isn't too concerned about the potential for disaster on a slippery circuit.

"Add water to it, yeah; it's going to be different; the risks become greater but it's the same for everybody," the DJR Team Penske driver told AAP.

The Gold Coast 600 starts on Friday with three 30-minute practice sessions.