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Driving Impressions:
Overall, the Cobalt’s driving
dynamics are impressive. On the
road, its suspension is
super-poised, with .90G
cornering capability, and a taut
but smooth and supple ride.
There’s no harshness for such a
competent car. Cornering is the
best I’ve experienced in a FWD
car, and I am seriously
considering autocrossing it as
well. Braking is also superb,
with front Brembo brakes and
well-balanced ABS.
Tuned at the Nurburgring, it’s
apparent that GM’s Performance
Division put extensive effort
into the handling dynamics of
the car, also setting a world
record with it at The Ring. This
immensely capable package is not
quite as well-suited to
dragstrip use, for the
low-profile tires and
significant low-end torque of
the car make it challenging to
launch hard. However, this is
not unusual, for no one
wheel/tire combination can do it
all, and great handling,
low-profile tires just can’t
create the footprint needed for
strong dragstrip launch
performance.
The direct-injected (DI) engine
is almost eerily smooth! At
lower RPM, where port-injected
engines can be a bit rough,
causing you to downshift, this
DI engine is just as content as
can be. It begs to be shifted
early in regular commuting,
which can only help fuel
economy. I also find myself not
remembering to upshift in
cruising mode, as the engine is
not buzzy when revved. Overall,
this is one smooth operator!
On to the Track!
The car does really fun 2nd gear
burnouts, as the videos will
show. Fact is, I was overdoing
the burnouts, but it was hard
not to...the car just boils the
tires once they get moving! Next
time I will take it easier, but
tonight was time to have some
fun with the new toy.
I first tried the stock launch
control, and quickly moved past
it. I don’t doubt that with more
track time, one could optimize
it more, but I was on a mission,
and I needed to get right to the
best launches I was capable of.
It seemed that the
aggressiveness of the launch
control system was more targeted
for street-style traction, not
the much harder bite of the
dragstrip.
Launching conventionally, with a
few whips of the throttle to
spool the turbo, netted me much
better results. I got to the 2.3
and 2.2 range of 60-foot times
immediately. But tirespin was
still evident, and I knew I’d
have to really tiptoe through
first gear to get the results I
craved.
13.60’s came quickly as I
continued to refine my launch
technique. I also experimented
with conventional shifting, then
with ‘no-lift’ shifting. While
the ‘no-lift’ shift seemed quite
foreign to me, after a few
passes trying both methods, I
realized it was the way to go.
Standard shifting, while
effective on the street, was
less effective at the track,
especially once I got
comfortable with ‘no-lift’. My
experience with drag racing my
11.9 second Solstice has taught
me that these ETC (Electronic
Throttle) cars are just not the
same as manual throttles for
fast upshifts. Data shows no
matter how quick you are, there
is a lag from throttle closing
to re-opening. Sure, it’s
fractions of a second, but in
drag-style upshifts of 0.3
seconds, a tenth is 33% longer,
2 tenths almost twice as long.
These longer throttle closed
times diminish turbo response as
the throttle opens in the next
gear. So, no-lift shift was the
way to go if I wanted the best
possible Elapsed Time (ET).
Fortunately, my PPC Tuner also
extended the redline in 1st and
2nd to 7000 RPM. This is
effective to keep the driver
from hitting the rev limiter
with the faster revving
additional power enables. The
3rd – 4th upshift came a bit
earlier, at 6200. Very little
time spent in 4th, but running
out 3rd with no upshift is not a
possibility with 105+ MPH trap
speeds.
The last two passes of the night
saw me really figure it out. I
skipped right past the 13.50’s
with a 13.45, and while there
was still a lot of tirespin in
1st, I knew I was closer than
ever to the sweet spot. I was
right! Next I skipped right past
the 13.30’s (and almost the
13.20’s!) with a solid 13.20 @
104.33 pass. The 2.09 60-foot
time was far and away the best
of the night, and the rest of
the pass was spot-on, with
perfect shift points. I tend to
save the best for last on these
nighttime tuning sessions!
What could stand improvement?
Well, even though these are
excellent numbers for a car with
just an exhaust and a tune, the
current package is not
optimized…yet. Weather was poor
for high power.
The tire combination can be
improved dramatically. As a
skilled FWD racer, it took me a
number of passes to coax out
that 2.09 60 foot. I’ve been as
quick as 1.79 on small drag
radials with my SRT-4. That
alone would take this car into
the 12.80’s easily, even in the
same weather. The still
relatively new engine may also
develop a bit more power as the
piston rings seat in fully.
Intake air temperature data was
collected and analyzed. The
temperatures, especially deep
into the run, can be improved
with a more efficient
intercooler. The stock piece,
while fairly good-sized, uses
the typical tube-and-fin type
core common to OEM applications.
It heats up more quickly with
the additional airflow and boost
we’re making now. We’ll apply an
intercooler very similar to what
we currently build for this LNF
turbo engine in Solstice and
Sky. These intercooler units are
massive, and not only improve
peak power and reduce heat
intake to the engine, they also
improve low-speed turbo
response.
And that’s what we will do next.
First improve traction, and then
upgrade the intercooler. We
should have more results later
this month!
What else are we working on
for SS/TC?
• Performance Intercooler
• Air Intake Upgrade
• Intercooler Tube Upgrade
• Blow-Off Valve Upgrade
• Downpipe / Cat Con Upgrade
• Turbocharger Upgrades (a
couple of flavors TBA)
All of these items will be
complimentary to one another, as
well as to our SS 3” Cat-Back
Exhaust and PPC Tuner. Using
them as a system will allow one
to avoid the problems we’ve seen
with mixing up items from
different vendors on Solstice
GXP and Sky Redline (other cars
we’re noted for that feature the
turbo LNF engine).
What should I get first for
my SS/TC?
Hahn/BSR PPC Tuner and Hahn 3”
SS exhaust. Without a doubt, as
we’ve proved in other turbo LNF
applications, this is the best
bang for your buck.
What are the goals of our SS/TC
development program?
We intend to meet, and then
surpass, the performance of our
SRT-4 program, which resulted in
11.8 second, 122 MPH runs with
true bolt-ons and street tires.
In doing so, the car must retain
100% daily driveability and fuel
economy, with no tradeoffs to
the new power level save for
excessive tire wear!
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