Racecar Engineering – September 2019

SEPTEMBER 2019 http://www.racecar-engineering.com 91

andprovidesa verygoodexampleofhowyou
lookatthesimulateddata.
Thelastthingthatwaslookedatwaswhere
togowiththedamping.Thebasespecdamping
providedontheracecarwasreasonableand
a quickscanofthedamperdatadidn’tshow
anyparticularproblems.However,I figured
I mightaswellthrowsomemudatthewall
andseewhathappens.SoI useda simpledual
ratedampermodelandthenusedtheshaker
rigtoolboxtoseewhatdirectiontogoin.The
resultsareshowninFigure 5.
DuetoconfidentialityI’mnotatlibertyto
disclosethedirectionI wentwiththedamping.
WhatI cantellyouis thatthebaselineis black
andthesuggesteddampingis red.Theinputis a
constantvelocityheaveinputandthefirsttrace
is theheaveresponseandthesecondis thecross
pitchmoderesponse.Thestand-outresultis the

Figure 5: Standard vs suggested damper specs

lower CPL value at the front and the lower cross

pitch mode response in heave. If I see something

like this, and if I have time, I put that on the

racecar. Unfortunately, at this stage of the game

at Le Mans I was running out of time.

Summing up

There were a number of things to note about

what transpired at Le Mans. Firstly, the time

requirements were not excessive, everything

that was done here was done in two sessions.

There was a two- to three-hour time session

to dial the model in. The set-up sensitivity was

completed in four hours, and this was with me

running off to see other customers, too.

Secondly, this was a great example of how

you should look at a model and the simulated

data to get a set-up direction. We didn’t do

anything fancy here, we just looked at the

aeromap and tuned the set-up to get the

simulated ride heights where they needed

to be throughout the turn-in to mid-corner

condition. That was it. I just kept it simple. It’s

just evaluating the data as you would for the

race, but using a slightly different lens.

In summing up I usually give a quick recap of

what we did and why we did it. But this month

let me take a different tack and tell you about

the results. The purpose of all this was to make

sure the car qualified midfield, and that was

the case. The car had good race pace, which

was unfortunately spoilt by gearbox issues in

the race. But let me leave you with the words of

Roberto Hernandez Garcia, the race engineer

for the car. ‘ChassisSim was just the final push

we needed at Le Mans. We start to go from baby

steps to real step in our performance. Many

thanks for your help and for your tools.’

The time requirements for all this were not really excessive,

everything that was done here was done in two sessions