Ambrose will be at Symmons Plains this weekend working with his replacement Scott Pye, who has been charged with helping the team's technical direction.
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Having returned from nine years in NASCAR, Ambrose feels his own adjustment process is slowing the new DJR Team Penske alliance's development to an unacceptable degree.
“It was a combination of a lot of factors,” Ambrose told V8 Supercars' media partner News Ltd.
“It became obvious to me that returning to be the lead driver in this one-car team, and trying to improve the car — ultimately by race results and also by engineering the car — was harder than I had expected.
“So the duty on my shoulders, as a relative rookie in a series that has moved on, was to improve the racecar and the results.
“When it became obvious I couldn't do that … it became an untenable position on me personally.”
Stay tuned to Speedcafe.com for the full story on Ambrose's decision, including an extensive interview, to be published later this morning.