At the halfway point of the season, Quintarelli and his teammate in the #23 NISMO GT-R Tsugio Matsuda are seventh in the standings and 18 points away from the leading Real Racing Honda pair of Bertrand Baguette and Koudai Tsukakoshi.
Quintarelli and Matsuda delivered Nissan's revised 2020-spec GT-R its first win at Suzuka, but this remains the only trip to the podium for one of the Yokohama marque's crews this year.
The #3 NDDP/B-Max Nissan of Katsumasa Chiyo and Kohei Hirate has not finished higher than sixth so far this year, while Kondo Racing has managed just a single point and Team Impul is the only GT500 crew that hasn't yet registered a top-10 finish.
#23 MOTUL AUTECH GT-R
On he and Matsuda's title hopes in general, the Italian added: "Suzuka [Round 6] is the last race with big handicap weight, so it’s the last chance for the cars behind in the championship to recover. My aim is at Fuji and Suzuka to close the gap as much as possible.
"If we are still more than 15 points when we get to Motegi with half handicap weights, it will become difficult to regain big points. We need to finish at least once more on the podium either here or Suzuka. This is the aim for us."
Impul driver Daiki Sasaki meanwhile is confident of a stronger showing at Fuji this weekend after the chance of a strong result disappeared at Motegi with a poor second stint.
#12 Calsonic IMPUL GT-R