Lotus Technical Director Nick Chester talks about preparations for 2015.

Nick, the development of the E22 was a massive undertaking with all the regulations changes. How big a project is the E23?
Indeed preparations for the E22 were massive - there were so many rule changes as well as a new power unit to take into consideration. Everything was different, it was a huge undertaking. The E23 project is somewhat reduced due to more stable regulations and although we have a new power unit the architectural changes are much less challenging than changing V8 to V6 turbo. There are still a few rule changes for 2015 like the front of chassis dimensions which also has a bearing on suspension installation and also a significant change to nose regulations. Overall the regulation changes aren't too vast. For us the big change is the power unit so it still is a sizeable project but not as far reaching as for the development of the E22.

Can you outline the development timeline?
We started working on the 2015 project in January this year. Each year, I define a development graphic according to our needs and to the regulation changes for the following year. At first we tend to have smaller groups of people working on next year's project. These groups then grow as the season goes by. We have various cut off dates throughout the year: when certain parts need to be released by the aero department to go to design and then from design to production. Our first chassis is being laminated now and we will gradually produce all the parts for the car. We will be starting to build the E23 in early January. The overall timeline is around a year turnaround. A more normal timeframe than the one we had for the E22 which we started developing over two years prior to the launch as there was a lot of prototype tests to complete.

How does the change from Renault to Mercedes impact on the programme?
There are a number of differences that we need to take into account like the packaging, the heat rejections, and the cooling requirements. At the same time, had we continued with Renault Sport F1, there would also have been modifications in the package for 2015. My feeling is that it won't represent significantly more work. It is more a matter of adapting to a new type of packaging and different requirements. In some ways, it will be relatively painless as Mercedes are quite fixed about what they need for their power unit installation. It means that there won't be too many iterations, at least less than when the V6 was introduced last year. It is a more defined programme.

How different from the E22 is the E23 likely to look?
The nose will look different as we could already see during the practice session test we did in Austin last week. I guess that it can be described as more conventional. The body work of the E23 will be a bit tighter: the engine cover and the rear wing will be different. The front wing should look quite different too by the first race. Really the whole car should look quite different and seeing it regularly in the wind tunnel, it looks quite nice!

Which areas in particular are we targeting for improvement?
We look at all areas when designing a new car. The big areas would be the aerodynamic performance where we obviously have struggled this year. There are certain areas where we want to improve the aero characteristics; the rest of it is around packaging the Mercedes power unit.

How much have we learnt from looking at the other teams' interpretations of the 2014 rules and regulations?
We always look at the other teams the same way as they do. There are a few interesting interpretations out there and it is interesting to look at the detail of the body work and at what they are trying to achieve with their cars. Everybody is always looking at each other to try and understand what the competition are aiming at. There are some different aerodynamic approaches which are interesting and we also look at how the cars are designed and manufactured.

We have almost a full season completed, how different has racing been in 2014 relative to 2013 and earlier?
Very different really. We are used to it now but at the start of the year there were huge changes to take in: from how you use your energy, to how to get the most of the car in qualifying and in the race. In terms of tyre performance it probably hasn't changed the way we operate that much. For the race engineers this year's changes meant a bigger workload in terms of car management. For example preparing the options on use of ERS energy for race and qualifying is an additional significant workload. There has been a significant increase in what they have to talk to the drivers about and in the ways to prepare the car to run.

If you could revert any outlawed aspect of car design from the past, what would it be?
That's an interesting question! A lot of the designs were interesting in their own era, like the sliding skirts, double diffusers and bigger engines. They probably wouldn't fit with the way the sport has developed for efficiency and safety if they came back! Because we are always focused on what makes our car go fast, we would revert to what helped us in the past like the mass dampers, suspension links etc. We don't tend to think about previous eras much since our focus is always to extract the best performance from the current regulations.

We've evaluated a 'conventional' nose for 2015 - was there any possibility to do anything unusual in the ilk of the E22's nose?
I don't think so. There are always different ways of interpreting the rules but I think that most teams will go down the route of conventional noses in 2015.

Will our 2015-spec steering wheel look radically different from the one used this year?
Yes it will, as I guess will be the case for most teams. We will test a steering wheel with a big display in the Abu Dhabi test.

Are the drivers involved in 2015 developments? Apart from free practice testing...
We gathered all the feedback that the drivers have given about the current car and made sure we understood where they feel the shortcomings are so we can rectify them in the new car. In the past that might have involved the steering feel or brake response. We take note of everything to feed it into the E23.

Does have driver line-up stability over a period of time help with the development too?
It does, yes, as you get better at interpreting the drivers' feedback.

What type of preparatory work is the team able to do in the simulator?
There is quite a lot that we can do and getting some assessments from the drivers in the simulator will help us with the E23 development. They will get their first taste of the Mercedes power unit and we will also look at our aero packages taking results from the wind tunnel to run them through the simulator.