Home Run Hero

This LS1-powered Impala SS could take the world by storm, if only it gets the chance

By Chris Endres
GM High Tech Performance

Big, bold and brash.  It is these three adjectives which best summarize the Chevrolet Impala SS of the 1990s.  Such glowing praise was an abject about-face for a body style that had been universally mocked since its introduction in 1991.  So hideous and bulbous was the re-skin of the venerable Caprice Classic that black and white police versions were quickly dubbed Shamu.  They were that god-awful.

So to hear the collective gasp (followed by a thunderous roar of approval) from the automotive world when Jon Moss unveiled his Caprice-derived Impala SS concept car in January 1993 was unexpected.  Gone were the strange triangular C-pillar windows, droopy rear wheelwell openings and superfluous chrome.  In were a striking C-pillar redesign, big wheels and tires, gallons of black paint and, most importantly, a powerful new engine.  The Impala SS concept car was such an overwhelming hit that GM fast-tracked it to production, where it arrived as a 1994 model.  Sporting 17-inch aluminum wheels and a 260-horsepower iron-headed version of the hot LT1 mill, it was a very capable performer.

The Impalas built over that glorious three-year production run were not the fastest or most luxurious or best handling cars of their time. But they had that certain savoir faire that spoke to enthusiasts. Chevy had truly turned lemons into lemonade. Alas, the radiant Impy lasted just three model years, as its Arlington, Texas assembly plant was re-tooled for truck production. Essentially, they got it right and almost immediately, unceremoniously killed it. Ladies and gentlemen, I present to you the pitfalls of brand mismanagement.

Fast-forward a handful of years to the re-introduction of the front-wheel drive 2000 Impala.  In spite of its unmitigated sale success among the general public, B-body loyalists howled in protest at the emasculation of their once-proud four-hooved mammal.  The new Impala was the polar opposite of its forerunner.  Small, practical and underpowered had seemingly become the new catchphrases for GM passenger cars, particularly where the Impala was concerned.  Let's face it: even the optional 200-horse 3800 V6 doesn't have the oats to push the 3,400-pound car to inspire full-throttle awe.  [It does, however, have the muscle to out-accelerate, out-handle and out-brake Ford's full-sized Crown Victoria, but we're also dealing with the popularly perceived benefit of rear-wheel drive and V8 power.--Ed.]

It doesn't take much imagination to picture our knee-jerk reaction to this Impala SS nestled among the dreamy hot rods at the 2002 GM Toys Test.  "Gee-whiz," we thought, "someone must have really knocked themselves out bolting lowering springs and new wheels to a ho-hum Impy."  Unimpressed, we sauntered over for a closer inspection anyway.  Boy, were we surprised to find an honest-to-Pete LS1 nestled discretely between the shock towers!  Jon Moss had once again pulled the proverbial rabbit out of the hat.

The Impy's engine started as a production Corvette item that was modified to fit in the chassis and work with the FWD running gear.  The rear face of the block was machined to accept an adapter plate that meshes with the 4T65-E four-speed transaxle.  The rear of the crankshaft was then shaved 4mm and a one-off stainless steel pilot bushing was created to allow torque converter installation.  The Corvette's gull wing oil pan was far too wide for the installation, so a new structural aluminum pan was cast.  Likewise, the OEM water pump was another source of interference, so a billet aluminum pump was carved out to perform the duty.

A stock intake manifold with an F-body cable-actuated throttle body was installed backwards, allowing the induction system to be placed comfortably in the front driver's side corner of the engine room.  An airbox from a 3800-powered Monte Carlo was sliced and diced in an attempt to provide sufficient airflow for the voracious LS1.  Though the right (rear) bank header is a custom stainless piece, the left (front) bank is a production F-body unit.  Bottom side, they are mated by a custom y-pipe that leads to stainless muffs and 2.75-inch tailpipes.

Besides the fairly extensive cooling system mods, surprisingly few additional mods were required.  The engine runs on a tweaked Gen-III Powertrain Control Module, while the fuel system is standard-issue Impala.

Outwardly, the SS was kept low key.  A few low-profile emblems populate the sheetmetal and keep pace with the subtle blackout theme.  The 17-inch billet wheels add some flash while the BFGs try to keep up with the torquey V8.

Back indoors, there is standard LS-level leather buckets with some SS embroidery and a bit of racy carbon fiber trim.  Perhaps the most interesting addition to the interior is the inclusion of a Monte Carlo gauge cluster.  This six-gauge transplant provides all essential info to the driver, including a rev-counter whose importance cannot be overstated for the rev-happy LS1.  Nice touch.

Front-wheel drive V8 combinations are nothing new, even at GM. Oldsmobile was shoehorning its 455-inch monstrosity in the FWD Toronado in the mid-'60s.  Newsflash for you: V8 power in FWD configuration is just as outrageous an idea now as it was then.  Torque-steer and massive quantities of tire smoke might not appeal to some bluehairs, but if driving the front wheels is the only choice, we'll take it in spades.  Besides, with modern power management strategies, any negative downsides can be reduced and even eliminated, thanks to our friend the computer.  At any rate, the first thing we'd do with a production LS1 Impala SS is disable any anti-slip tomfoolery.

The bottom line is that low-volume niche markets are where it's at.  One needs to look no further than the success of Corvette, Viper, Lightning and even the re-born Thunderbird to see that cookie-cutters are out, niche is in.  We now know that GM has the capability of turning out front-wheel drive LS1 cars, so why not treat the Impala marque with the dignity it deserves?  If you're out there reading this, Mr. Moss, please, puh-leeez, figure out a way to make it happen.  Then the world can really see how front-wheel drive performance should be done!

CHEVROLET V-8 IMPALA SS VEHICLE SPECIFICATIONS
Configuration
Five Passenger, four-door sport sedan
Front Engine, Front Wheel Drive
110.5" Wheelbase
62.0" Front Track /61.1" Rear Track
3,381 lbs. Total Weight - 2,185 lbs. Front / 1,196 lbs. Rear
Drivetrain
Aluminum 5.7l LS1 16-Valve Pushrod Engine
4T65-E Four-Speed Automatic Transaxle
Chassis
Independent, McPhearson Strut Front Suspension
Independent, McPhearson Strut Rear Suspension
4-Wheel Disc Brakes With Abs
Rack & Pinion Power Assisted Steering
Body / Interior
PPG Crystal Black Exterior Paint
Ebony, Perforated Leather Trim Interior
Unique Badging/ Graphics
Impala "SS" Interior / Exterior Package
Engine
Displacement 5.7/ 346 Cu. In.
Bore And Stroke 99.00 X 92.00mm (3.898 X 3.622 in.)
Compression Ratio 10.0: 1
Torque @ rpm 382.2 lbs.-ft. @ 4600 Rpm
Horsepower @ rpm 371.9 bhp @ 5500 Rpm

This is a direct reprint from GM High Tech Performance.  Go to their site to see the photos.