Page 35 - MotorTrend (March 2020)
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terrific limited-slip e-diff, a trick
learned from years of racing
the tail-heavy Porsche 911.
A limited-slip is a very strong
tuning device when on or off
throttle, as opposed to steady-
state cornering. Tighten it up,
and the car will want to go
straighter and will be more
predictable. I rather brashly
suggested that they increase
the lockup off throttle on that
limited-slip e-diff. Petrucci
countered that they wanted testers drive the same cars Randy Pobst is a
the car to point to the apex for hours every day, they learn two-time class
winner of the 24
midcorner. “Oh, it does, sir, too very well what it wants. But in a
Hours of Daytona
much,” I said. “It’s nervous. Your perfect car, it’s a natural thing, with more than 90
customers will spin it. Make it no adaptation needed. Isn’t professional race
wins. Numerous
more stable for when they do perfect the goal?
automakers
a sudden lift off the gas, which With more stability from have hired his
they will.” the action of the diff, Team diagnostic and
testing services
Petrucci, a still-waters- Corvette can reduce the
as a dynamics
run-deep type, calmly and steady-state understeer simply consultant
quizzically replied, “I have by the book, with softer front during vehicle
never heard our drivers or stiffer rear springs and bars. development.
mention off-throttle oversteer.” And as for the 80-plus-mph
Well, it’s there, big as life. (I’m oversteer, hook the e-diff up Raceway, we have found some of that in
not at all sure I said that out longer on power, too, to reduce
the C8’s track personality. It really will
loud, but I sure thought it.) that tendency. This car is not
point to the apex entering a corner and
Keep in mind these Chevy powerful enough to be wheel-
sometimes overdo it and end up side-
testers have been driving the spinning at that speed, but a
ways, with the widely adjustable stability
twitchy C7 for years, which Z06 or ZR1 would be.
control switch fully off (thank you for
colors their impressions. Also, The capabilities of an
providing us with that choice, Chevy).
power immediately stabilizes electronically controlled limit-
But when you apply your American
this chassis, to its credit. Finish ed-slip differential may be the
V-8 torque, then you find the greatest
braking and go right to power, magic bullet for squeezing the
improvement in driving the American
and the issue mostly disap- very best from the Corvette C8
Sports Car: It puts ponies to pavement.
pears (doing so in the C7 made at the track. It’s a fine machine,
matters worse). And stability and these suggestions could The C8 hooks up. Chevy has taken
control covers it up. Also, there put an even finer point on it, advantage of placing the engine over the
may well be a forest-for-the- leaving no negatives at all on rear wheels, and that loading successfully
trees effect. When the same which to focus. Randy Pobst creates forward thrust far better than any
Corvette before. The new ’Vette launches
hard from a slow corner or a stoplight/
dragstrip. Check out that 0–60 time,
beating cars with far higher power ratings
and even some with all-wheel drive. That,
my friends, is traction.
In fact, the ’Vette transfers weight
rearward so well that it sometimes goes
into another kind of slide: understeer.
The front loses grip a bit prematurely as a
result of the light front loads. What to do?
Is it bad? No, but this is a brand-new baby,
and there’s still something to be learned.
We believe we will see the C8 Corvette
improve further as the Chevy team learns
more about this all-new mid-engine
phenomenon.
In street-tuned mode dashing around
VIR, the ’Vette revealed deliciously
instant steering response. It was quick
and stable as I carved into a corner, and
it revealed snappy trailing-throttle over-
steer when I released the brake. Both are
clearly influences of the mid-engine low
polar moment.
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