Red Bull Chief Designer Adrian Newey believes the major reason behind the Constructors' Champions' struggles at the first official pre-season test at Jerez last month was a lack of time.
The Milton Keynes outfit completed only 21 laps at the Andalucian track, less than any other team present in Jerez.
Previously, the majority of the blame for Red Bull's struggles in testing was laid at engine provider Renault's door, Newey admitted that they should take a lot of the blame themselves.
"What stopped us at Jerez - on our side as opposed to Renault - was a problem where the bodywork local to the exhaust was catching fire," Newey told BT Sport at the RAC Annual Motoring Dinner.
"It was really a lack of time [that caused the problem]. It was something we could have proved out on the dyno if we had managed to get everything together earlier. But Renault have been up against it in terms of their use of the dyno; [and] we have been up against it making the parts in time. So had we been a couple of weeks further ahead then that could all have been done in private on the dyno. But unfortunately it was done in public. Hands up on our side.
"The Renault seems to have a particularly large cooling requirement.
"It is certainly a challenge to package everything in. The radiator area we need to cool the charge air from the turbo and additionally all of the extra cooling we need for the electrical side of things - the batteries, motor generator unit, control box - is roughly double last year's car with the V8. So trying to package that in without compromising the aerodynamics too heavily is a very big challenge."