Scott McLaughlin has sold the helmet he wore during the latter half of the 2017 Supercars season for $46,200 with the money to go towards bushfire relief.
The New Zealander, who will today sample a Team Penske IndyCar at Sebring, will match the sum, taking his contribution to $92,400.
Added to the auction was a race worn race suit from the same campaign, contributed by DJR Team Penske boss Ryan Story.
From a starting price of $1,000, bids had exceeded $44,000 within an hour.
That figure continued to climb with the winning bid coming in early on Saturday morning.
McLaughlin is one of a number of leading figures within the motorsport community who have chipped in to the fund raising effort.
Formula 1 world champion Lewis Hamilton contributed $500,000 while Daniel Ricciardo, Toby Price, Molly Taylor and others have also offered items up with proceeds to go to charity.