Prodrive has confirmed Liam Doran will drive its Mini John Cooper Works RX for the first time at next month's X Games in Barcelona.
The Mini RX was driven non-competitively at the British Rallycross Championship meeting in Lydden Hill last month with a World Rally Car engine fitted.
The second X Games event of the year will mark its first race with full rallycross power.
Doran, who will test the car at Prodrive's Warwick venue early next month, said: "When I drove the Mini WRC at Lydden, you could immediately feel how good the chassis was.
"While it didn't have the power I am used to, you could see that, with some engine modifications, it would make a great rallycross car.
"It will be great to be the first person to drive a properly works-engineered Mini RX and, I think, as such an iconic global brand, it will very quickly become a favourite of the fans on both sides on the Atlantic."
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After converting the shell and chassis from a World Rally Car into a lighter-weight Mini RX, Prodrive worked on the engine, retaining the WRC's 1600cc powerplant, but with significant mapping and intercooler revisions.
The first phase of this engine development has netted an extra 60bhp, with the second phase expected to deliver a similar figure, giving the Mini more than 400bhp.
Prodrive engineer Paul Eastman said: "We know it is already not that far off the pace of the rallycross entries.
"With the initial extra power it should be a match for the two litre cars on the short stadium tracks for the X Games in Barcelona and Munich and then there is more to come in time for the longer US events."
Doran will contest all three remaining X Games events in the Mini, as well as the Bristol and Atlanta Global RallyCross series races in America.