Toro Rosso launched its STR8 a single evening before the start of winter testing, and upon its unveiling immediately drew attention to the host of changes that were put on the car. The team even noted that the steering wheel is the single part that was carried over from the STR7.
First of all, Toro Rosso has maintained its nose cone philosophy that it introduced at last year's Jerez test by using a long nose cone that extend quite a bit ahead of the front wing. It is also still a very flat and sharp cone, even though a vanity panel now covers the step at the front bulkhead. In fact, Toro Rosso appears to be the only team yet to have its vanity panel attached by screws. Other teams chose for a lighter solution by bonding or glueing the panel on the structural nose cone. Having seen what other teams are doing, it would not be much of a surprise to see a new nose on the STR8 soon, lacking the screws to fix the vanity panel.
The monocoque itself meanwhile is still designed with the front bulkhead at its maximum height, attempting to catch more air underneath the nose to divert it to the car's floor and diffuser. Just like in 2012 this again seems to be the most popular solution among all teams.
As with Sauber, a team that Toro Rosso aims to compete with, a lot of effort was put in the development of the sidepods. The team's chief designer Luca Furbatto noted that the major undercut sidepods had reached their maximum potential and were very hard to develop further. Indeed, the team first intruduced this sidepod concept in 2010 on the Toro Rosso STR6 and aimed to provide a clean stream of air underneath the sidepods and straight onto the diffuser.
While this concept was revised on the STR7 with a minor reduction of the undercut, the new STR8 does away with it almost entirely, allowing the radiators to be mounted much lower than was previously the case. This will substantially lower the centre of gravity of the car as many other components, like the ECU and electronics can also be positioned much lower to the car's floor. In addition to that, the wetter surface of the sidepods is reduced, thereby lowering the surface drag, partially offsetting the increase in drag that is caused by increasing the frontal surface of the sidepods.
The lower position of the car's components however allow the sidepod to be tapered downward much faster towards the rear, resulting in lower exhausts and therefore possibly making it easier to get the exhaust gases down towards the diffuser.
The above image also shows that the airbox is similar but has been given a more round inlet aperture. The smaller inlet underneath, in between both roll hoop support pillars is still there, but has become smaller, a change that was likely possible because the main sidepod air inlets have slightly increased in size.
The rear suspension is also brand new, as Furbatto pointed out: "We have a revised rear suspension, with the emphasis on making it more aerodynamic, in order to generate more downforce. When designing the chassis, again, providing a platform for aerodynamic development was an important consideration. In terms of suspension layout, kinematics and internals those are again brand new. The STR7 was very limited in terms of set-up possibilities and with STR8 we opened up this aspect substantially, adding devices and features not present on previous STR cars. This should allow race engineers and drivers to perfect the handling and ride behaviour of the new car."
Finally, a marker was put on the rear wing, which now features a different curve of the main plane. It has to be said however that the current wing is very similar to the rear wing design most used during the 2012 season. The monkey seat is also new, along with the central tail funnel. It is expected that most teams will retain the monkey seat at almost every race as they find it increasingly difficult to add downforce in different ways.