Chester: The Lotus E23 is a massive step forward

Lotus F1 Team Technical Director Nick Chester talks us through the E23 explaining why it is a massive step forward from its predecessor.

How would you describe the E23?

The E23 should represent a massive step forward for us. It’s no secret that we struggled with last year’s car so we’ve targeted every area that caused us an issue. We’ve made strong progress in the wind tunnel as well as in areas such as packaging and cooling. We expect the E23 to perform far, far better than its predecessor.

Which areas have been focused on in the E23’s development?

Obviously a massive change for us is working with Mercedes AMG HPP, our new power unit supplier. We made this change as it looked and looks to be the one area of the car which could bring us the greatest performance gain. It’s not just performance, but reliability and driveability as well as packaging and cooling too. The E22 did deliver good figures in the wind tunnel, even if it was difficult to unlock its potential, so we’ve paid more attention to making the characteristics of the car more adaptable. In terms of the suspension, we were delivered something of a blow last year when the front-rear interconnected suspension was outlawed mid-season. The E23’s suspension design is specific to the updated regulations so we’re not trying to update a system originally intended to work a different way. We learnt a lot in many areas of the car over the course of 2014 so there are many lessons which have been applied. We think we’ve made a good step. We won’t know how our car will fare in relative terms until we’re out in action at a Grand Prix, but we certainly expect to be much more competitive than last year.

Can you be more specific about some of the changes?

Obviously, the heart of the E23 is the Mercedes AMG HPP power unit and the packaging is significantly different to our 2014 unit. The 2015 power unit has some packaging advantages and it works well with our chassis layout. We have taken the opportunity to change our cooling system significantly to be much simpler and more elegant than last year. The different regulations have also introduced further changes, particularly with the front of the chassis having a gradient introduced which has required new front suspension, so we’ve had plenty to keep everyone at Enstone very busy in the off-season.

How straight-forward has the development progress been?

With the impact of a new power unit supplier there has been a lot of work and it’s only us and McLaren who have different suppliers in this area for 2015. There’s a lot to learn, not just in terms of the physical aspects of the engine and ERS installation, but also in terms of personnel, working practices, software and so on.

The E22 wasn’t the most reliable of cars, how has this been addressed for the E23?

With the massive regulation changes brought in for 2014, all of the teams faced a challenge to their previously strong reliability records which was a natural consequence of the changes and the new, emerging technology. We’re still very early in the life of these regulations so it’s perhaps optimistic to expect the reliability of any car to be back at the levels seen by the end of the previous generation of cars, but from our side we’ve painstakingly analysed every aspect of the E22 which caused us a headache and we expect much more consistent running from the car this year.

Can you give any further insight into areas addressed?

In 2014 we had a lot of problems related to exhausts or to the charge air system coming into the engine; either the cooling of the charge air or the associated pipework. The 2015 exhausts follow a different concept. We did get on top of last year’s concept, but it was certainly an area where we suffered at the beginning of the year. On the charge air side, the cooling is far simpler than last year’s and we’ve paid a lot of attention to the pipework to get away from some of the sealing issues we had on the E22.

The E22 was the first car of a new generation of F1 regulations so was it was a very different beast from its predecessors. How different an animal is the E23?

The E23 is quite a different beast from its predecessor. The change of nose at the front of the chassis leads to a different aero concept for the front of the car, which then affects the flow behind it. The packaging of the power unit meant we’ve changed the shape of the rear of the chassis a lot; partly for installing the power unit but also partly due to what we can do at the back of the chassis giving us some advantages in how we control the air flow there. The E23 is in many ways a far simpler car than then E22 and we think this will give us some advantages relating to our ability to evolve. The packaging is more compact, partly though the power unit installation and partly through what we’ve learnt with the associated ancillaries. All of this should reap benefits.

What do you expect the development curve of the E23 to look like?

Hopefully it should start pretty steeply and continue on an upward trajectory for quite some time! There’s a lot of potential and in some areas we’re still just scratching the surface. You always see a lot of aero progress through a season and the information coming from the wind tunnel looks very promising. We’ve also got a good programme for development with the suspension and the brakes which give us a reasonable spring in our step.

How much more work is involved with changing to a new Power Unit?

It’s a significant chunk of work. At the design phase, it’s a new package and system of integrating the power unit with the chassis, then there’s how the power unit manufacturer works – what information you’re given and in what format they share this information and the processes relating to working practices and the interaction. It’s a new relationship so there are naturally different ways of doing things. Having said that, Mercedes AMG HPP have been fantastic and what could have been a quite difficult transition to a new power unit has been very straightforward indeed.

What are the changes to Pirelli’s tyres for 2015 and what has the team done to better extract their performance potential?

The rear construction has changed to offer a little bit more grip. We’ve looked at different ways to assist us to generate tyre temperature and we should be assisted in this regard with the new power unit and how we can harness this. We’ve also targeting making the E23’s performance more easily accessible by the drivers so that Romain and Pastor can feel more confident and better able to extract the final tenths over the course of a lap and repeat this better over the course of a race. The E22 wasn’t the easiest car to feel confident in and push to the limit; the E23 should be far better in this regard.