90 2014 CHEVROLET RACING SPECIAL
AERO FOR GO, NOT SHOW
As well as removing hot air from the engine
compartment, the hood vents on the Z/28
reduce front-end lift. Overall, the Z/28 body
isn’t just designed to minimize lift – it actually
produces downforce at track speeds, thanks
to an aero package that includes a front
splitter and integrated under-engine panel,
extended rocker panels, a functioning rear
diffuser and a large rear spoiler.
GS IS “STREET STOCK”
Central to the Continental Tire SportsCar
Challenge is that the competing cars are
standard, volume-produced models available
for purchase in the U.S., with performance-specific modifications kept to a minimum.
The Grand Sport class features large-capacity
six-cylinder or eight-cylinder sports cars and
performance sedans, plus smaller capacity
four-cylinder models with forced induction.
Preparing the Z/28 for competition,
which long-time Chevrolet partner Pratt
& Miller Engineering was tasked with,
mostly involved tailoring the potent road
car base package to what the Continental
Tire SportsCar Challenge rulebook allows
or prohibits for the Grand Sport class.
“I would say 90 to 95 percent of the
changes we made were due to the rules,”
says Lisa Talarico. “Most of the production
systems worked really great and didn’t
need to be touched, but a lot of the things
that needed changing were done because
they didn’t fit within the regulations.
“The brakes are probably the most
significant item we had to adapt for GS.
The production car has carbon ceramic
brakes and the series doesn’t now allow
them, so we had to go in a different
direction with steel brakes for the racecar.
So, given that the production car comes
with better brakes than we’re allowed to
race with, that wouldn’t really fall into a
performance upgrade category.
“The Z/28 racecar gets a full roll cage,
racing seat and harness, plus the rest of
the safety enhancements outlined in the
rules, plus we’re allowed to use some
lighter body items, the racing shocks and
the change to the final drive…and there’s
just not a lot else to call out.”
When Pratt & Miller finished the first
example of the GS Z/28, testing and
comparing the car with its bone stock
brethren soon followed.
“We did our first real track test at Road
Atlanta in early November of 2013,”
Talarico explains. “And then we had two
more tests prior to the end of the year –
one at Savannah in Georgia, which was
for engine validation, and one at Daytona
in mid December, which was really about
developing and fine-tuning the racing
version of the car. We’re a much bigger
car than most of the cars we race against,
so we have more power to make up for it,
but we still need to see where the GS
Z/28 is at, relative to what we know
about the stock Z/28. Improving things
like top speed in order to be competitive
is part of the development process.”
For GS, the Z/28’s carbon ceramic brakes had to go...
PLAYING BY THE RULES