Championship leader Mark Winterbottom says he needs more speed from his FG X, after his Prodrive teammates led the way on Sunday at the SKYCITY Triple Crown.
While 'Frosty' still recorded commendable results across the three races - cominghome second, seventh and fifth over the weekend - he believed he let his Prodrive team down after failing to make the podium in Sunday's 200km race, which saw David Reynolds and Chaz Mostert score a 1-2 finish, with Brad Jones Racing's Fabian Coulthard home third.
"I was trying to stay out of trouble for a good result but I need to find some pace," he told v8supercars.com.au.
"Clearly the cars can do it because both the other guys did a good job, and their engineers. So we'll just work on what I need and try and get it better.
"But I just feel like I let the team down a bit not being on the step with them because three cars would be pretty cool. Fifth is still a good result but we're not quick enough."
Winterbottom is hopeful upgrades that ran on Reynolds' and Mostert's cars will help at the upcoming July 10-12 Castrol EDGE Townsville 400. Car #5 did not receive the upgrades because of the risk factor -but Winterbottom emphasised that the team needed to continue developing the cars to avoid getting swamped by the opposition.
"There [were] new parts on #55 and #6 this weekend, so I'll get that for the next round," Winterbottom said.
"It's a bit of a risk, and [we] don't want to risk it but ... there's always different upgrades and you need them because people jump you and you do what we did last year and just fade away. So [we must] keep the speed, that's what's going to win."
He added that it wasn't just those upgrades that helped Reynolds particularly to the front, which for the Bottle-O racer broke a drought that stretched back to 2013.
"It's not just that - but everything helps. His car and the way he drove was good."
The gap from Winterbottom to Red Bull's Craig Lowndes is 95 points, with 300 the maximum a driver can earnover a race weekend.
"I've got the lead and that's good, but I need pace - it's way too early to be relying on [having the lead]," he said.
And while Lowndes -and right-hand man Grant McPherson, who was Winterbottom's race engineer in 2014 - isthe one righton his tail, Frosty has his eyes on other competitors, particularly third placed Fabian Coulthard who suffered incredibly bad luck on Saturday in Darwin, failing to make it past the first corner after incidents that weren't his fault.
"Coulthard's the one who this weekend really should've dominated, he probably got away without a few points there - two weren't his fault and even he could've been leading as well."
Winterbottom's other rival Jamie Whincup - who he has been battling on the track since karting days - is down in eighth position and 286 points away from the lead. But the Prodrive racer knows not to write off the six and all-time champ despite the team's recent rough patch.
"Lowndes is doing a good job, and Shippy [McPherson] is doing a good job as well.
"I don't know about Jamie but he's the sort of guy that is down then he goes and dominates... he's won six Championships because he can come back...
"There's a lot of quick guys but we've proven we've got quick cars."
Catch Winterbottom on tonight's episode of Inside Supercars at 7.30pm EST on FOX SPORTS 506.