Racecar Engineering – September 2019

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

side-wallofthesurvivalcellfromthebulkhead

behindthedriver,downtothefrontofthe

chassisandalsoacrossthebottomofthe

chassis,wrappingunderneaththedriver’slegs.

Onthis,LigierandTatuusdivergedsomewhat,

withtheformerchoosingZylonpanels,while

Tatuusoptedforreinforcedfibreglass,which

performslikeZylon,butis lessexpensive.

‘Tostaywithinthepricecapandthebudget

forthiscar,wehadtogoforthismaterialrather

thantheZylon,whichis slightlythinnerand

lighter,butis alsofarmoreexpensivethan

reinforced[fibre]glass,’Casiraghisays.

Inaddition,eachwheelhasanextratether

designedtoholdthewheelclosetothecarin

caseofanaccident,witheachtetherdesigned

towithstand6kJofenergy.

Helloto Halo

Asmentionedabove,aswithallnewFIAsingle-

seaters,F3Rhasincorporateda Halointoits

design.‘Wewerethefirsttohomologatea steel

Halo,forthesamereasonsasthesideintrusion

panels,’Casiraghiexplains.‘TheexistingHalo

[designs]wereonlytitanium,whichis lighter

butveryexpensive.Justtogiveyoua number,

thetitaniumHalois somethinglike€15,000

minimum,andwehaveanoverallcostforthe

chassisof€80,000,sothetitaniumHalowould

havejustbeenunaffordable.Wehadtodesign

a steelversionoftheHaloandestablishand

testthedesignofthisattheFIAlaboratoryat

Cranfield.It is somethingthatwesellallaround

theworldtoothermanufacturers.’

Allofthesesafetyadvanceshaveresulted

inextraweight,bringingthemassofthe

Tatuus,withoutdriver,to670kg,whiletheLigier

weighsinatjust630kg.‘TheLigierJSF3Ris

verybalancedandtheweightdistributionis

verygood,’saysCrawford.‘Theadditionalsafety

parametersactuallyhelpedthebalancewith

theextraweightonthefront.’Casiraghiis also

keentonotethatdespitetheextraweightthe

T-318possessesgoodweightdistribution.

Passnotes

Bothofthesemachineswereconceivedwith

a focusontryingtoreduceaerodynamic

sensitivityforfollowingcars,inanefforttomake

overtakingeasier.Withthisinmindthefront

winghaditsmidprofiledefinedina similar

mannertocurrentFormula1 regulations,with

theaimofmakingtheturbulentairlesscritical.

Attherear,thediffusersizeis limited,withthe

aimofminimisingtheupwashthatcoulddisturb

followingcars.Crawfordsays:‘Youdogeta little

bitofaerowash,butit’sminimal.’

Althougheachchassisis spec,individual

championshippromotersareallowedtoopt

forwhateverengine,gearboxandelectronic

packagetheydesire,althoughbothCasiraghi

andCrawfordsaythishasnotpresentedthem

withtoomuchofa problem.‘Thishasbeen

mainlypartoftheworkwehavedonewith

The individual championship promoters are allowed to opt for

whatever engine, gearbox and electronics package they desire

F3 REGIONAL – TATUUS T-318 / LIGIER JS F3R

Photo:

Ligier

Automotive

Chassis

Carboncompositemonocoqueto FIAF3technical

regulations;full 2018 FIAsafetycompliance.

Bodywork

Composite.

Engine

Honda2-litre,4-cylinder16-valvewithturbocharger;power,303bhp

fortheF3AmericasChampionship.

Gearbox

6-speedsequential;pneumaticpaddleshift.

Suspension

Doublewishbone,frontandrear;pushrodadjustable

ridefrontandrear;JRi2-wayadjustabledampers;front

andrearadjustableanti-rollbars.

Steering

Rackandpinion;quickreleasesteeringwheel;

safetycollapsiblesteeringcolumn.

Electronics

LEDbacklitcolourdisplay;CANcontrolledpower

management;3-axisplusyawaccelerometer;damper

potentiometers;highspeed4GBLogger.

Brakes

Alcon4-pistonmonobloccalipers;PFCventedsteeldiscs;

Tiltonadjustablepedalmountingassembly.

Safety

Frontcrashstructure;rearcrashstructure;sideimpactstructures;

Halo;sideandfrontanti-intrusionpanels;6-pointharness;6kJwheel

tethers(twopercorner);on-boardfirecontrolsystem;headrest

compatiblewithHANS;extractableseat(all 2018 FIAcompliant).

Dimensions

Length,4895.5mm;width,1850mm;wheelbase,2920mm.

Weight

650kg.

TECH SPEC: Ligier JS F3R

(in F3 Americas configuration)

The Ligier JS F3R. Halos are mandatory while the design of the nose is tightly controlled for safety reasons. This means that all F3R racecars will look very similar from the front