Tandy and team-mate Mathieu Jaminet won two races in the new GTP category this year and had a third taken away following a technical infraction found in post-race scrutineering at Watkins Glen.
Porsche has identified the longer-distance races as where it needs to focus its efforts and has made a number of updates aimed at improving reliability with its 963 prototype.
“There’s been lots going on with the car and at [Porsche’s development center in] Weissach,” Tandy told Motorsport.com. “It’s mostly based around reliability.
“We’re trying to iron out the flaws that we’ve found in both software and hardware. Looking back at last year at the four longer endurance races, including Daytona and Le Mans, we weren’t that great, were we?
“This is the first thing, we need to finish these long races, so that’s been the main focus. We’re obviously better prepared from a reliability point of view. Of course, everyone is still going to have some issues, all the cars are still pretty new, but it’s definitely a better feeling now.”
After a planned test at Daytona last month had to be scrapped due to resurfacing work near the Bus Stop chicane, the two days of running last week were the only chance to test the upgrades ahead of next month’s Roar test, qualifying and the season-opening Rolex 24 Hours itself.
“It’s the first time we’ve run the car back here since the race, so we’ve got a season’s experience and learnings to put into it,” said Tandy. “The second car [the #7] was purely putting mileage to validate stuff, carrying on from what we ran at a private Sebring test [last month], but it’s not just updated parts it’s putting everything through the whole process again.
“We’re not prepping for a sprint race, so this is the perfect time for reliability testing, and our car [the #6] was more focused on performance, such as tire testing and general stuff.
“We had a couple of issues, which were kinda Daytona specific. Here you run high RPMs for a long time, so that’s here and Le Mans-specific, and you’re also on the banking here for a long duration. The high lateral load on the car is unlike anywhere else we go, so that’s fluid surge and high suspension loads, steering and tires.
“So, there are Daytona-specific test points that we need to learn.”
Tandy revealed that the problems were “nothing we haven’t experienced before” and the car returned to the track each time after remedial work.
“We learn something new every day with this car at the track,” he added. “A couple of things we had to come back to garage for, which is not ideal, and it’s the sort of thing that will impact your race massively.
“We’re still not where we need to be, that’s clear, but we’re working to get there. This is the last point to make that decision about what gets prepped for race week at Daytona.
“So, no more messing around after this week – we get locked in on all our parts and software strategy that we’re going to come and race with.”