Racecar Engineering – September 2019

(Joyce) #1

18 http://www.racecar-engineering.com SEPTEMBER 2019


FORMULA 1 – TORO ROSSO STR


everyteam;youinvesta lotoftimeandmoney
andyouwantit alltowork.’
Withthemethodologyofhowthe
racecarwouldbedeveloped,adjustedand
potentiallyimprovedset,attentionturnedto
thedesignitself,andthepreviouslymentioned
shortcomingsoftheSTR13.‘Wefeltthatthe
operatingwindowoflastyear’scarwasnot
bigenough,it wasdifficulttosetupandon
occasionit wasdifficulttodrive,’Egginton
says.‘WiththeSTR14wewantedtoopenthe
operatingwindowandgivetheengineers
morefreedom.Wewantedtoallowthemto
setthecarupwithoutsufferingthenegative
impactofanaeromapwhichwasperhapstoo
sensitiveorpeakyina highyawcondition,
or[ofhaving]a rearrideheightcharacteristic
thatperhapsmeantthatyouhadtorunthe
rearendstifferthanyouotherwisemighthave
wantedina smallrideheightrange.
‘Sothechallengewastoexpandallofthat,
whichcancostyouperformance.Weespecially
wantedtoimprovelowspeedperformanceas
well.Thenontopofthatwehadtheregulation
changesoactuallyonpaperallthethingswe
weretryingtodo,allthechangeswewere
making,werea littlebitscarybecausewewere
notsurehowwewouldrecoverthelossesfrom
thechangesinthefrontwing,forinstance.’

Aeroconcerns
The 2019 aerodynamicregulationchanges
meantworryfortheSTR14designersbecause
a keyobjectiveofthecar’sdesignwastomake
it asadaptableaspossible.‘Wedevelopedthe
conceptofthecartogiveusasmuchfreedom
aspossibletodevelopandaddperformance
withouthavingtomakebackground
architecturalchanges.Wehavea development
pathforourcarinthewindtunnel,butat

Chassis
Mouldedcompositemonocoque.
Engine
HondaRA619H(seepage26).
Transmission
RedBullTechnologies(2018specification)composite
casingwithXtracinternals;eightforwardgears,onereverse;
multi-platecarbonfibreclutch.
Suspension
Unequallengthcarbonfibredoublewishbone,withpushrod actuated
torsionbars(front),pullrodactuated(rear);Inboardfrontparts and all
rearcomponentssuppliedbyRedBullTechnology.
Brakes
Carbon-carbonwithBrembocalipersto ToroRossodesign.
Tyres
Pirelli.
Weight
743kgminimum(80kgdriverminimum).

TECH SPEC: Toro Rosso STR

‘The operatingwindow of last year’s car wasnot bigenough,


it was difficult to set up and on occasion it was tricky to drive’


a Renaultpowerunit,yettheToroRossois
Honda-powered.TheFrenchandJapanese
unitshavesignificantlydifferentshapes,with
thelatterusinga splitturbochargerlayout,
withthecompressoratthefrontoftheblock,
whiletheRenaulthasa conventionaldesign
withcompressorandturbineattherear.This

any given moment one change can lead to
something else and that can lead you down
a different avenue,’ Egginton says. ‘We are not
really in a position where we can bring complete
update packages to change our direction
and that means we have an evolutionary
development approach, rather than revolutions.’

Bull market
One way that Toro Rosso reduced the level of
uncertainty with certain areas of the STR
design was to revise its model of what is made
in house and what is bought in. For many years
the team has prided itself on having bespoke
transmissions, even when Toro Rosso used
Ferrari-engined versions of Adrian Newey’s Red
Bull Racing chassis it persisted with its own
gearboxes. That has all changed in 2019, with
many parts of the STR14 being supplied by Red
Bull Racing including the gearbox, making the
STR14 the first car in many years to come out of
the Faenza factory without a bespoke casing.
‘The rear end has been provided by Red Bull
Technology. We are taking a gearbox casing and
rear suspension although many of the internals
of the gearbox are similar to parts we have used
in the past,’ Egginton says. ‘It’s a bit of a mix of
parts, the rear end of the car, the gearbox casing
and the main suspension parts are from the
Red Bull RB14 [the 2018 car]. The time-scales
for using RB15 [the 2019 car] parts were not
really compliant with our timetable, our design
process and timing is different to them, as is our
car build. But the RB14 parts are fine, there is no
compromise there, it just made more sense to
use them. They are a known quantity.’
Using the Red Bull RB14 gearbox gives
the STR14 a composite casing, with internals
from Xtrac. However, a key issue with the
2018 ’box is that it was designed for use with

Red Bull RB14 gearbox was designed for use with a Renault engine, but it also fits the Honda in the STR


Rear suspension, brakes and uprights all come from the RB

Many RB14 front suspension parts are also used on the STR
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