James Key’s latest competitor out of the Toro Rosso factory looks mighty competitive next to the rest of the grid. The STR11 isn’t revolutionary in design, but it does take the current trends to a new level of execution.
After preseason testing at Catalunya, the outlying elements that peak interest on the STR11 are as follows: S-duct fed by NACA inlets, blown front axle with an angled outlet from the wheel nuts, larger split airbox, tight rear end with floating gearbox, complex Monkey Seat and rear wing endplates.
The central inlet of the larger airbox feeds the compressor, while the flanking inlets on either side feed other heat exchangers. Moving more cooling to the airbox takes away from the sidepods, and while that may raise the center of gravity, coke-bottle zone aerodynamics are improved. Mercedes have followed suit as well in 2016 with this concept.
Unfortunately for the junior Red Bull team, the new chassis is hampered by last year’s Ferrari power unit. Toro Rosso will be stagnant in power as all the other teams will benefit from a 2016 power unit along with in-season updates. Scoring early in the season will by key for Toro Rosso
Most teams take in air for their S-duct with a thin slot running the width of the nose. James Key’s use of NACA ducts seem to exist so the under-chassis aerodynamics are disturbed as little as possible as the air makes its way around the turning vanes to the rear of the car.
An S-duct is helpful in this regulatory climate as it dumps a boundary layer of air on top of the chassis leading to the cockpit and helps the air running over top of the chassis stay attached; this is especially helpful to aerodynamicists as they try and keep their chassis height high, meet the low nose tip regulations, and build short noses to put the center front wing mainplane into play and increase under chassis airflow.
Without an S-duct the air would hit the top of the angled nose, follow it for a bit, and keep rising, detaching from the bodywork as the chassis leveled off.
The Toro Rosso monkey seat debuted in the second week of testing is the most complicated I’ve seen with four elements (the top split in two on either side) and open angled pressure-releasing endplates. The rear wing endplates also have these slots open to the airflow on the leading edge.
The STR11 incorporates, as every other team besides Renault, an inverse Mickey Mouse exhaust layout, the ears supplying the wastegate exit.
Pioneered last year, Toro Rosso have kept their swan-neck centerline rear wing support that passes through the main exhaust outlet; this acts as a flow conditioner for the exhaust plume and reduces drag compared to the inverted Y-lon solution that would otherwise take up space with supports snaking around the exhaust pipe.
Another area of note is to either side of the rear wing mainplane. The rear wing endplate regulations give a maximum width more than most teams need, so teams such as Toro Rosso have build in multi-element wings to the inboard side of the endplate and slats on the outboard side to increase downforce.