SOMEBODY CALL FOR MORE POWER?: CALLAWAY TURNS THE
IMPALA SS INTO A SUPERNATURAL HONKER by John P. Cortez (Autoweek,
Callaway Cars, as usual, has its own salvo to fire in the
Horsepower Wars. Its latest creation is the SuperNatural Impala
SS, a 404-hp, 383-cubic-inch version of Chevrolet's lame-duck
A Virginia Chevy dealer who recently bought one told a
Callaway marketing guy that the car could use more power. ''When
it comes to power, some is good, more is better and too much is
just right,'' he said. And so the SuperNatural is merely better.
It certainly does not have too much power for our tastes; either
404 horses aren't enough to hammer this beast all the way home,
or Callaway's number is optimistic. This car is fast, but much
more noticeably so at speed than from a standing start. Callaway
claims 0-60 mph in 5.5 seconds, and 14.2 seconds through the
quarter-mile; compare this to our track numbers for a stock
Impala SS: 7.5 seconds from 0-60 mph, and a 15.8-second quarter.
You feel the power more, and forget how big the car is,
cruising the interstate. This car will get you from 70 mph to 95
faster than just about anything else so huge (4218 pounds). Punch
the throttle on your favorite freeway and your posterior gets to
know the back of the seat intimately.
Power surges through GM's stock four-speed automatic
transmission, which will kick down into second with the least
provocation. But a manual tranny, as in Jon Moss' six-speed
310-hp Impala SS (AW, Oct. 31, 1994), would move the Callaway
closer to dream-car status. Because Chevy doesn't build them as
such, and Callaway can't afford to recertify the car for
emissions standards with a manual, no stick is available.
Callaway's Impala rides low and looks mean, at least in black.
An add-on tach sits unobtrusively on the dash to the right of the
steering wheel. The stock digital speedometer remains.
The SuperNatural engine, based on the 5.7-liter LT1 V8, is
also available for Roadmaster, Fleetwood and the rest of GM's
rear-drive sedans. It can be installed by Callaway, or any other
certified shop. The engine operates on the hot rodder's principle
that adding just the right amount of fuel to more air will result
in more power. Callaway's Honker SS intake system brings cooler
air to the manifold. The system's software measures the improved
airflow and provides the optimum air/fuel ratio, getting maximum
performance from cylinders that have been honed .03 inches over
stock to add an extra 33 cubes. As air leaves the free-flow
SuperNatural SS Exhaust system, you hear it in an exhaust
cacophony of NASCAR-like proportions.
The suspension package includes Koni shocks and Eibach springs
that lower the car a noticeable half-inch. The car handles truer
than the stock version, thanks to a stiffer setup that makes the
big ol' body less anxious to roll. The ride, on the other hand,
won't beat you up any more than the typical pony car's might. Fat
Goodrich 275/40ZR-17 Comp T/As make this Impala more sure-footed
than the stock version (315/35ZR-17s are optional at the rear).
When it's time to stop the beast, front 13.1-inch Brembo vented
discs answer your foot's call. Rear brakes are standard 12.1-inch
vented discs (the stock brakes are 12-inch, front and rear).
Callaway claims its Impala will stop from 60 mph in 115 feet, 11
feet better than the stock Impala SS.
All the improvements are available separately. The engine is
$14,878 installed, and the tires, brakes, suspension and tach
push the tab past $20,000. Add that to the price of a fresh
Impala SS, and the Callaway Impala reaches the mid-$40,000 range.
GRAPHIC: Callaway's SuperNatural system and a bit more
displacement make a whopping 404 hp in chevy's LT1 V8.