18 HONDA 2015 RC/SO AERO KIT
Understanding how the 100-plus parts
that comprise Honda’s aero kit work in
unison isn’t the work of a moment. Tripped
like wing-shaped dominoes, items packed
onto the front wing influence every surface
that follows. And once the air leaves the
last piece of bodywork, that domino effect
continues as that turbulence is passed to
the next car in the train.
Working in concert with the base Dallara
DW12’s spec underwing, early aero kit
figures suggested the 2015 cars would
gain at least 1,500lbs of downforce over
the stock RC/SO kits used in 2014. With an
incredible 5,000lbs of maximum downforce
last year, drivers had struggled to turn their
mounts in the fastest corners. But with the
number leaping to 6,500lbs in initial aero
kit testing, the rest of the D W12 chassis –
notably the suspension – was encountering
stress and force levels that exceeded
design thresholds. Once driver safety was
called into question, IndyCar reacted.
“The performance potential is so great
with aero kits that it’s a delicate balance
to make sure you don’t cause other parts
of the car to have issues,” says HPD vice
president Steve Eriksen.
To bring peak downforce back to a
safer level, IndyCar made adjustments
requiring both manufacturers to remove
the same pieces from their spec floors.
Compared to the 2014 floor, the final ’ 15
specification surrenders around 1,000lbs
of downforce. So with most of their gains
wiped away, Honda and Chevrolet
responded by turning the topside of their
cars into a downforce lover’s dream.
“When IndyCar removed the strakes
and sidewalls from underneath the car,
we were determined to make up for that
elsewhere,” says HPD chief engineer Tom
Reichenbach. “And since we only had the
top surfaces of the car to modify, that’s
why it looks so aggressive with the big
number of wing elements to create
downforce – we were trying to get back to
and exceed where we were last year.”
Taking the effort that went into the
original aero kit, then combining it with a
near-total redesign late in 2014 to
accommodate IndyCar’s rule changes
required Honda to expend a sizeable
amount of time and resources to meet
THE DOMINO EFFECT
No part acts in isolation on Honda’s new-for-2015 RC/SO
aero kit. Like dominoes falling, each influences the next...
The aggressive look of Honda’s aero kit
isn’t for cosmetic reasons. The quest for
downforce defines every component.
TOM REICHENBACH, HPD
“YOU ONLY GET ONE SHOT AT
TAKING ON THIS CHALLENGE.
YOU HAVE TO GET IT RIGHT
THE FIRST TIME”
the challenge. But word is, the 2015
downforce figure for the RC/SO kit is at
least 5-600lbs up on the ’ 14 baseline.
“We started a year and a half ago with
preliminary analysis, moved into CFD,
then built the wind tunnel parts and went
there to sort the good ideas from the
bad,” Reichenbach explains. “Then it was
track testing to verify the wind tunnel
data, and then onto full production. With
the changes, a lot of that was repeated.
“We’ve doubled the size of our chassis
department because you only get one
shot at taking on this challenge. You
have to get it right the first time.”