44 F1 RACING AUGUST 2019
PRO
RACING04 Engineering:Trickle-downtechnology
“So the challenges start there – wheredo you actually put
three additional motors? You have twoMGU-Hs and one
MGU-K, so three motors, not two like in F1, as well as the
batteries and inverters, so the problem is to find a place to
fit all these parts. TheMGU-H has to be connected to the
turbo system, but then thecar is very busy atthe f ront, so we
decided to put the MGU-K at the rear. The car is rear-wheel
drive so it makes sense to have the MGU-K there, but we
mounted it to thedifferential because we didn’t want to add
the extra torque to the propshaft and have tochange the
gearbox as a consequence.
“All the decisions came one after the other andeach
presented all sortsof challenges in terms ofweight and
engineering solutions. To accommodate the MGU-K we had
to cut intothe body ofthe car, so then we hadto make it
stiff again, adding metal around it. Then we had the issue of
where toput the batteries and the inverters, so we decided
to get rid of the rear seats. And of course, keeping all these
elementscool is a big issue. If you compare this car with the
normal Q60 it has many more air intakes.”
The detailing of the Project Black S haschanged during
its journey from design concept to working prototype,
based largely on the cooling demands of the powertrain.
Renault F1’s Enstone and Viry-Chatillon facilities have been
intimately involved, not only in the finessing of the hybrid
components but also in supplying aerodynamic expertise.
Naoki Tokunaga, deputy technical director of the F1 team to
James Allison during Enstone’slast periodunder Renault
ownership, has overseen the architecture and integration
of the hybrid systems.
While the Q60 donor car has a turbocharged V6
powertrain, the internal combustion engine has little
in common with an F1 car’s, apart from the number of
cylinders. Since it’s a twin-turbo design there was no optionto run an F1-style system in whichthe blower is split across
either end of the engine block withthe shaft and MGU-H
running within the ‘vee’. That also meant two MGU-Hs–
arguably the most troublesomeelement of an F1 powertrain
in development terms – rather than one. It’s also beena
challenge to integrate the operations of the hybridsystem
and the brake-by-wirewith the gearbox, which is an off-the-
shelf unitwith its ownpropr ietary control electronics.
“Apart from the power delivery,” says Volpe, “which is the
first objective because you want to have a more performing
car, the other thing wewanted to replicatefrom theF1
expe rience is the complexity and sophistication of the
system in the way youcan managethe energy.”
The vision for the driving modes is to offer separate
power managementstrategies: a ‘street’ setting that offersa
sustainable power boost for normal use, a ‘race’ setting that
delivers extra power over a shorter duration – five or six
laps in the context of track use – and ‘quali’ mode that goes
all-in on power for a single lap. Two further modes prioritise
cooling and recharging, barelytapp ing into the 160bhp of
extra boost available from the hybrid system.
The outer shell of the Black S is similar to the design
study but very different in detail. To cope with the cooling
demands of the MGU-K, the exhausts have been relocated
from the centre to the outer edges ofthe rear valance; an
additional radiator above the diffuser outputs directly intoa
low-pressure zone behind the car.
“Within the [Renault-Nissan] Alliancethis is known asa
‘square vee’ project, which means completely from scratch
from the platform up,” says Weaver. “So, knowing it [the
platform] was the Q60 Red S, wewent from the beginning
and sketched as if it were a concept. We wanted topush the
identity as far as we could. And this was before we started
to develop with the guys at Enstone, incorporating theirThe rear wing was developed from aRenault Sport F1 Monza
chord. Even though it was a low-drag wing, it was producingtoo
much downforce so the angle was substantially relaxed