Answering the question that...
Answering the question that nobody asked, we are proud to present our newest project vehicle, Project Killer Whale. Yes, it's a cop car. And yes, it has an LT1. Our baseline pass was a rather modest 15.251 at 91.11 mph. With 115,000 miles on the clock, it's really not that shabby.
Chevy's Caprices, Biscaynes, and Impalas embodied everything that was great about America. These cars offered full-sized American value with glamorous shapes designed by pens and emotion, not by committee. Big chrome bumpers and stadium-sized interiors rested on a rugged full frame to offer a sublime and assured ride that could handle any roadway that came across its cast-iron path.
In the early 1970s, full-size cars were still selling briskly despite the temperamental OPEC situation that often relegated larger cars to the used car lots and the bottom of resale value charts. To meet the demands of its customers, in 1977 Chevy introduced an allnew downsized Caprice/Impala set on a shorter 116-inch wheelbase. In a move to improve fuel economy and ef-ficiency, the new car was offered with a 305ci V-8 rated at 140 horsepower, choked by a Rochester two-barrel and a pellet-style catalytic converter. But as the Caprice and most every other GM car during the 1980s began to lose market share to the imported competition, GM felt the traditional Caprice of yesteryear needed a radical makeover.
In a rather bold maneuver, Chevy prewent for a completely new concept with its replacement and put a rounded silhouette onto its full-framed chassis from model year 1991-96. Gone were the chrome bumpers and traditional styling cues. In their place came urethane bumpers, higher-quality interiors, and later on, LT1 power. Sales went into the toilet. The jellybean shape never caught on with anyone except those responsible for taxi and law enforcement fleet sales. The conventional Caprice buyer no longer paid attention. By the mid-1990s, the damage was already done, and in 1996 the last of the great ones rolled off the assembly line.
Our first mod: An Edelbrock...
Our first mod: An Edelbrock cat-back exhaust system. While not something we would normally do trackside, we were fortunate enough to have the track rented for our testing exercise. But to our own chagrin our exuberance and enthusiasm were quickly tempered as we wasted the entire day dealing with rusty bolts and broken nuts (figuratively speaking, of course) to get the old exhaust out. Once the new Edelbrock exhaust was bolted into place, we lost out on the weather advantage as the temperature soared from 88 to 91 degrees Fahrenheit, but we did see a drop in time to 15.037 at 91.45, so we gained 0.217 seconds and .34 mph.
Still, these cars have their loyal, faithful fans. To find out what all the hoopla was about, we decided to pound the pavement in search of a "bubble" B-body for some real-world driving impressions and dragstrip thrashing. Our search soon steered us toward the police sedans equipped with the 9C1 police package.
After about a month of looking, we found a relatively clean '96 Caprice 9C1 from a friend who once roamed the Midwest with the Iowa State Highway Patrol. With 115K on the clock, it had faithfully served with no major issues, as the well-maintained example had no record of accidents or major failure, and was delivered to our office doors for $3,000 even. The seller even included the nifty spotlight on the driver-side door.
To Race A Caprice Is To Love A CapriceLooking at the spec sheet, the Caprice had a few things working against it for optimum dragstrip performance. The curb weight, at 4,085 pounds (with a half tank of fuel and the spare tire removed), was somewhat of a surprise. We figured that the stripped-down Copper would weigh less than 4,000 pounds, but we couldn't do anything about it and moved on. Based on previous experiences with these cars, we expected the factory 260hp LT1 to catapult this double-row sofa on four wheels into the mid-15s. But to our surprise, the first pass netted us 15.251 at 91.11 mph with a 2.22 short time. Certainly not bad for our 88-degree test day, but we knew there was more in it.
The first order of business was a trackside exhaust system upgrade. By replacing the factory cat-back and its four mufflers with a larger, freer-flowing Edelbrock system, we were able to benefit from the system's 2.5-inch mandrel-bent pipes all the way to the tailpipes. Also, the sound that we now had bellowing from the rear of our Caprice was more befitting of an American V-8 icon rather than a plebian civil service vehicle.
Back on the strip, the cat-back was worth .217 seconds, as our timeslips dipped to a 15.037 at 91.45 mph from our previous best of 15.251 at 91.11 mph.
 The stock torque converter...  The stock torque converter on the left is not the original piece. As Pat related, "It's a typical massproduced rebuilt converter. It was probably installed by the police fleet repair shop at one point or another, and if anything, it would have made your car slower than if you still had the factory torque converter in place." On the right, Level 10's 10.5-inch converter is not only lighter, but it also offers a street/strip-friendly stall speed of 2,400 rpm for stronger launches. |  Heading over to Level 10 Transmissions,...  Heading over to Level 10 Transmissions, we looked for some more e.t. by installing one of its high-performance torque converters into our Killer Whale. But when Mike Bonassisa removed our 4L60E, we noticed a lot of play on the input shaft and some wear on the stator support shaft. Level 10's proprietor, Pat Barrett, suspected there was more damage inside and recommended a complete internal upgrade. We took his advice, and once everything was apart, his hunch proved to be right. |  Typical of 4L60E transmissions,...  Typical of 4L60E transmissions, our reaction sun shell's hub had fractured from fatigue and abuse. Broken right at the base where it meets the main body, it was hard to believe our Killer Whale was still able to move forward with just 10 percent of its teeth still transferring torque. |
 Our tranny also suffered from...  Our tranny also suffered from a heavily worn coupling between the reverse input drum and the reaction sun shell. This is caused by putting the car into reverse before coming to a complete stop at engine speeds above idle. |  GM used conventional circumferential...  GM used conventional circumferential seals in many places to separate the apply and release circuits within a shaft. When new, they were probably fine, but Level 10 replaces them with high-performance scarf seals that can expand or shrink in any condition, improving performance and reducing the internal fluid hemorrhaging that would reduce shift quality. |  Using four-pinion planetary...  Using four-pinion planetary gearsets, 4L60E transmissions can handle a good amount of power and torque. But with the increased torque from our planned engine mods and the Caprice's portly weight, Pat recommended a 4L65E gearset, which incorporates five pinions in each assembly. This offers as much as a 25 percent greater torque capacity. |