News

Are you sitting comfortably?

August 2014

The way you sit in a car is central to how you experience it, MPVs and 4×4’s favour a high-up “command” driving position, Sports Saloons favour a lower slightly more stretched out feeling whilst most family cars opt for a halfway house between the two with the emphasis on comfort.

Sports cars are different.

As a general rule you want to sit as low as possible with your legs straight, and your body is stretched out. This gives a nice low centre of gravity, the steering wheel is moved closer to your body, and the low seat base adds to the feeling of speed when you are driving.

Our car is a even more different for a couple of very good reasons. Very early on in the design process (pretty near the start actually) John and Mark hit upon the idea of having an aerodynamic floor on the car. We are not just talking about a rear diffuser (lots of people do that) but a front one as well.

Air flows under the front of the moving car, is accelerated by pressure and flows out from just behind the front wheels so you get downforce on the front of the car as well as the back.

Of course, you have to have space for the front diffuser and if we had a designed a “normal” sports car that would be where your feet would be. John, Pete and Mark’s Formula One design experience kicked in here: obviously you can raise the foot position about 11cms upwards over the diffuser whist keeping the seat base as low as possible: a feet up driving position…just like a formula 1 car (and indeed a lot of Le Mans and GT cars too). A convenient space exists between the two front diffuser outlets that also house our fuel tank aiding weight distribution.

A big question for the feet up seating position was “how comfortable is that going to be?”

Coming from a Production car background I have to say I was a bit sceptical about this as I’m used to designing road cars with nice big comfy seats, lots of legroom etc. Is different going to be better?

Sketches and CAD layouts can look great but ideas always need testing for real so firstly, a wooden full scale mock-up of the tub was built and the seat position refined. Then the Alloy XP1 car (our first test and development vehicle) was constructed last year and everyone got to try out the car for real.

One of my colleagues always used to tell me “trust the technology”, and driving a car you have helped design is always the acid test. XP1 has validated a lot of the ideas that have gone into the carbon fibre XP2 car and the seating position is just one of these.

It works really well: you don’t feel cramped up or awkward while driving and for the (admittedly short) stints that we tested the car, all seems to be working as advertised.

The seat on XP2 has its proper fore/aft and height adjustment too so we should be able to further fine tune things.

Now we just need to find out what it’s like for a couple of hours of proper driving…

Meet the press Goodwood Festival of Speed