Racecar Engineering – September 2019

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

F3 REGIONAL – TATUUS T-318 / LIGIER JS F3R

the FIA to standardise the interface of the

components,’ says Casiraghi. ‘It makes it easier

for the life of the design of the car, because

we don’t have to design specific bodywork for

each of the engines. It’s the same for the engine

pick-up points; it is a standardised pattern on

the chassis and the engine suppliers follow

the pattern that is in the FIA regulation. Similar

things apply to the wiring loom. The wiring

loom has a common standardised interface

between the chassis and the engine, which

again makes it possible to keep most of the

same electronics when we go, for example, from

an Alfa engine unit to a Renault engine unit, so

this is a very efficient way to work on the design.’

‘The engine bay is quite large and the

bodywork is quite large, because these are for

production engines,’ Crawford adds. ‘[Also], you

have a lot of options on the back of the tub for

the mounting of the engine.’

Engine ancillaries

For Tatuus the process of assessing each engine

fit begins once info from the manufacturer is

obtained, allowing it to calibrate surrounding

systems such as cooling. ‘The main job is

working on the systems that are engine-related;

every engine has its own cooling system,’

Casiraghi says, adding that in the case of the

Alfa Romeo and Renault, the former had an

exhaust on the left side, while Renault’s exhaust

emerged from the right. ‘We had to redesign the

exhaust system and the cooling system for the

different architecture of the two engines.’

Ligier also had to work hard to optimise

cooling solutions, mainly to counteract high

temperatures in certain areas of the United

States during the summer. ‘In the States, we

struggle with temperatures,’ Crawford says. ‘It’s

not unusual for us to run on 100degF [38degC]

days, so we spent a particular amount of time

with CFD and track testing with the radiators.

We also built a mule car, and we experimented

with the radiators and the intercoolers, so we

now have a huge window for cooling, and little

in the way of issues with cooling.’

The throttle is a fly-by-wire system and

the brakes hydraulics with sensors, with

safety cut-offs built-in to allow for engine

shut off should the system believe the driver

is applying significant pressure to the pedals

simultaneously. ‘In this case, in the ECU, they

have to shut down the engine,’ Casiraghi says.

‘If the driver is pushing the throttle and brake

while crashing, the engine shuts down. This is

something that is required by the FIA and only

possible if we have the fly-by-wire system.’

The suspension for the T-318 is a relatively

traditional layout with double wishbone and

pushrods for both front and rear, with dampers

arranged on top of the monocoque. At Ligier,

it was built in-house as aluminium machine

billet uprights. It is double wishbone, pushrod,

rockers and runs with JRI shocks. ‘It’s just a

conventional pushrod rocker system, all aero

tube,’ Crawford says. ‘The dampers are on top of

the monocoque for ease of change. Any spring

changes and adjustments are just a matter of

removing the damper cover and doing that.’

As it stands, Formula 3 Regional uses 13in

profile wheels, but the door is open to move

to larger wheels. ‘We expect this to happen

sooner or later and it will happen for sure when

Formula 1 moves to them,’ says Casiraghi.

Creating a car that is technically astute,

powerful, reliable, bolsters safety, but also

comes under a tight cost cap has proven a

challenge for manufacturers and one that

becomes greater still when spare parts are

also capped. At €80,000, the cost cap leaves

little room for manoeuvre, and Casiraghi

acknowledges this. ‘It is difficult, there is not

really one magic part that can help you; rather

it is very detailed work on every little part of the

racecar to save costs,’ he says.

Early success

For both Tatuus and Ligier these are still

relatively early days in Formula 3 Regional,

but so far it’s all been largely positive. ‘At the

moment, we are very satisfied, because mainly

what we have seen is that we started less than

one year ago and we have four series racing the

car and a fifth one ready to go,’ says Casiraghi.

‘We have now four championships with more

than 80 cars racing. We have the car for the

Toyota Racing Series, which will start racing next

winter. In one year to have something like 120

cars makes this project successful for us.’

Crawford also believes that the Ligier JS F3R

has proved its worth. ‘Cost containment is one

of Ligier’s main objectives and when drivers and

teams thank us for keeping costs low, it’s a huge

win not only for Ligier but the series as well.

‘We are also seeing the progression of

race drivers from karting and even through

into prototypes,’ Crawford adds. ‘These Ligier

open wheel racecars are great platforms for

development. Seeing our drivers progress into

higher profile pro racing already defines the

Ligier JS F3R as a successful car.’

The W Series is currently using the Tatuus T-318 F3R

racecar while New Zealand’s Toyota Racing Series is

to switch to this chassis for the start of its 2020 season

‘We built a mule car and experimented with the radiators and the

intercoolers and now we have very few issues with the cooling’