At the rain-shortened end of Thursday's private MotoGP testing activities at Sepang, Crash.net and Italian colleagues GPone.com sat down for an interview with Ducati Corse general manager Gigi Dall'Igna.

The conversation covered a wide range of topics, but began with today's track activities, where Casey Stoner had been riding the GP17 for the first time, alongside Michele Pirro.

But the slow-drying new asphalt had taken until the early afternoon to dry, only for a rain storm to soak the circuit several hours later.

"At the moment this test is a waste of time, because the track remains wet for a lot of time, so it's really difficult to make proper test," Dall'Igna said. "We've had, I think, one hour [fully dry] in two days. It's nothing."

"With Casey we are working with and without the wings. For sure we have a lot of things to test, including some new chassis. We have to explore which is best [in the middle of the corner].

"With Michele we are working in a different area, more relating not to the [official] test with Lorenzo and Dovi next week. Some different concepts."

Stoner returns from latest track run, using a wingless bike with the new 'black box' by the top exhaust. @Official_CS27 @DucatiMotor #MotoGP pic.twitter.com/swqw8xPkHX-- Crash.net MotoGP (@crash_motogp) January 26, 2017

The main talking point of this week's private test so far has been the new box and re-routed exhaust at the back of all the GP17s present. Pirro joked on Wednesday, the box was "to put salad in, in case I get hungry".

Fortunately, Dall'Igna was willing to give a few clues, mainly aimed at playing down the significance of the design.

Asked about the new 'concept', the Italian replied: "This is not a concept, it is a shape of the fairing."

Is the box empty inside?

"No, it's not empty."

But there is no fuel inside?

"No."

You've modified the exhaust to fit around the box...

"We moved the exhaust 30mm, so not a huge modification!"

Are all the bikes here this week using it?

"At the moment, yes."

So is it definitive for this season?

"Nothing is definitive! It is something we have to test and do a [back-to-back] comparison with Michele, but we've not had enough track time to do this. "

There are reports that Ducati has patented a 'jet exhaust' valve and that maybe...

"I've seen the reports... Ducati have a lot of patents!"

But it is not for use in racing?

"No. You can see the [GP17] exhaust and it is not in the direction of the [patent] drawings."

Another area of technical interest for 2017 is how MotoGP aerodynamics will change following the ban on wings.

"We made a test with Casey, the first exit was with wings, and the rest without because we have to understand the difference and what we have to modify on the setup to avoid any problems," Dall'Igna said. "Because for sure without winglets, and Casey can confirm this, the bike is more dangerous."

The fairings seen on the Ducatis so far this week contain no obvious surprises and there is a simple explanation: "This is more or less the 2016 fairing without wings."

So this fairing won't be used for racing?

"It depends if we find something better, then for sure we will use the new solution. Otherwise we have to start the season with this fairing."

Do you have new things to test with the fairing here?

"No. They are not ready... Frankly speaking, the reason why we wait with the [2017] fairing is because we need time to make a proper fairing. So we are working on the aerodynamics and we still have to finalise the job."

Exacerbating the difficulty of fairing design is the new aerodynamic freeze, which means only one fairing and front fender update will be allowed during the 2017 season.

"The shape of the fairing is for sure a problem, also because we have to freeze the aerodynamics from the first race," Dall'Igna confirmed. "We have only one step after that. So it's a real big problem to finalise the starting fairing for the Qatar GP."

Could you decide to use one fairing optimised for fast tracks and the other for slow tracks?

"[Nods a 'yes']. Could be. Could be."

Although he won't be riding until next Monday, when the official test begins, new superstar signing Jorge Lorenzo was present at the track to watch today's test and work with his new team

Dall'Igna described the visit as "normal", but when it was put to him that most race riders do not come to watch test riders, he added: "Jorge is a different kind of rider and I think that he would like to understand what we want to do to improve the bike."

Dall'Igna said that Lorenzo had been involved in listening to the feedback from the riders, while team manager Davide Tardozzi stressed the Spaniard says he "already feels part of the family".

There had been some rumours last season suggesting Stoner might be a kind of coach for Lorenzo, a theory Dall'Igna ruled out. Instead, Stoner's 2017 schedule is likely to be: "More or less like last year; three or four tests during the season. But it depends because maybe we need something more."

Will you ask Casey if he wants to race, or is that discussion over?

"I think that is a closed book. If Casey asks us to make a race, for sure we are happy to give him the opportunity, but I don't think so."

The private Sepang test - attended by test teams from all six manufacturers - concludes on Friday, but the likes of Stoner and Pirro are expected to also ride at the official test.