GM pours on the power

GM has entered into professional front-wheel-drive drag racing via the modified Chevrolet Cavalier (top) and Pontiac Sunfire.

A four-cylinder aluminum block engine on a front-wheel-drive Chevrolet Cavalier provides enough power to reach 272 km/h (169 mph) in 8.8 s during a quarter-mile sprint. Welcome to the latest motorsports competition craze.

"Front-wheel drive is new to drag racing," said Don Taylor, Group Manager of GM Racing. General Motors Corp. has entered the professional front-wheel-drive drag racing foray via two modified production cars: the Chevrolet Cavalier and the Pontiac Sunfire. Both racing cars employ modified versions of GM's production 2.2-L Ecotec engine.

For the 2002 race season, the Cavalier (driven by Stephanie Reaves) competes in the National Hot Rod Association (NHRA) Modified class and the Import Drag Racing Circuit (IDRC) Outlaw class, while the Sunfire (driven by Marty Ladwig) competes in the NHRA Hot Rod class and the IDRC Quick class. "Right now, we're the only true factory team participating in front-wheel-drive drag racing," said Russ O'Blenes, GM Racing Project Engineer, noting other manufacturers (such as Toyota, Honda, Mitsubishi, and Ford) provide team support in the form of parts and money.

According to Josh Peterson, Manager of Drag Racing Programs for GM Racing, "We're thrilled to campaign these cars across North America to show drag racing enthusiasts and consumers alike that front-wheel-drive cars don't have to sacrifice their production roots to be both exciting and competitive at the drag strip."

Cutaway of the production 2.2-L Ecotec engine, a 16-valve, four-cylinder engine available in a variety of GM vehicles.

The production Ecotec—available in the Chevrolet Cavalier, Pontiac Sunfire, Pontiac Grand Am, Oldsmobile Alero, Saturn L-Series and VUE in North America, as well as Opel and Saab models in Europe—is a 2.2-L, 16-valve, four-cylinder DOHC engine. As part of GM's global four-cylinder family, the production engine was developed by an international team that included engineers from Opel's International Technical Development Center in Russelsheim, Germany; GM Powertrain in Pontiac, MI; and Saab in Trollhaten, Sweden. The production Ecotec—depending on vehicle application—produces between 100 and 107 kW (135 and 143 hp) with a torque between 193 and 206 N•m (142 and 152 lb•ft).

"We're currently at the 800-hp level after starting with about 140 hp with the production engine as installed in a production car," said O'Blenes. "We were able to make between 370 and 400 hp with billet rods and forged pistons with everything else stock."

The production engine underwent various alterations, including the aluminum block (modified with stainless steel O-rings and copper head gaskets to withstand cylinder pressure resulting from the turbocharger); cylinder heads (ported and outfitted with dual-coil valve springs and titanium retainers—support was added for the numbers 1 and 4 combustion chamber); camshaft drive gears (slotted to allow adjustments in camshaft phasing); and camshaft drive (stock timing chain, guides, and hydraulic tensioner). "We were able to start with a really good base engine package," said O'Blenes.

In addition to retaining stock components whenever possible, goals of the racing engine program centered on producing more than 447 kW (600 hp) for the Sunfire application (which uses no intercooler) and more than 522 kW (700 hp) for the Cavalier application (which allows an intercooler). The desired power band was targeted from 5500 to 9200 rpm. GM Racing also wanted the durability to make 25 full power sprints between engine rebuilds. The program exceeded on all counts.

Early in the race season, the power band was ranging between 5500 and 9700 rpm, while engine durability was allowing between 35 and 55 full passes between rebuilds. To reach over 578 kW (775 hp), three primary aspects were key to the power supply. "The heart of it is in the cylinder heads—machining the ports to increase the airflow; the camshaft profiles—more lift and more duration; and the turbo," said O'Blenes.

Race version of Ecotec engine for the Cavalier, which underwent a variety of alterations before hitting the circuit.

The Ecotec engine used in the Pontiac Sunfire racing car is mated to a Hydra-Matic 4T65E electronically controlled four-speed automatic transmission that features a high-performance torque converter. An X-Trac six-speed sequential manual transmission is mated to the Ecotec engine powering the Chevrolet Cavalier racing car.

In addition to British-based X-Trac, other support partners include Bates Engineering of Torrance, CA (providing parts such as camshaft gears, O-rings, axle shafts, cylinder sleeves, and flywheels); Shaver Specialties of Torrance, CA (engine assembly); and Innovative Turbo Systems of Simi Valley, CA (turbochargers and turbocharger controllers).

- Kami Buchholz

Mercedes' direct-injection-gasoline engine

Mercedes-Benz' new supercharged 1.8-L gasoline four-cylinder direct-injection engine will be more powerful than the 2.0-L engine that it will replace.

On the eve of the Geneva Motor Show, Mercedes-Benz revealed that it is planning to introduce a 1.8-L four-cylinder, supercharged direct-injection-gasoline engine with balancer shafts. With 125-kW (168-hp) output, it is more powerful than the 2.0-L engine it will replace, but is said to be 19% more fuel efficient, returning a combined consumption of 7.8 L/100 km in the C-Class. The model will be designated CGI. Initially, though, the engine will be available with conventional fuel injection with a power spread from 105 to 141 kW (140 to 189 hp). All versions of the engine will be supercharged and fitted at first to the C-Class but later will go into other Mercedes-Benz model ranges. As well as a supercharger, each engine will have an intercooler, four valves per cylinder, variable valve timing, balancer shafts, and an adaptive drive system—all under the heading of Twinpulse.

The move to direct injection is not wholly new to Mercedes. The 300SL Gullwing built from the early 1950s was the first series-produced car to use a four-stroke gasoline direct-injection engine. According to the company, the CGI engine has two separate intake ports that ensure optimum swirl in the mixture, thus making combustion fast and as complete as possible. Each port has an adjustable fuel flap. A high-pressure fuel pump is driven by the intake shaft. A pressure regulator controlled by the engine computer regulates the pressure in the fuel rail, which is directly connected to the injectors. The engine, which has exhaust gas recirculation and secondary air injection, meets EU-4 emissions requirements. Up to 35% of the exhaust gas can be recirculated. The engine has a linear oxygen sensor that becomes active immediately on cold engine startup. A newly developed NOx sensor with digital control is used.

The three conventionally fuel-injected versions of the new engine in the C-Class will be produced as the C 180 Kompressor, C 200 Kompressor, and C 230 Kompressor, all with 1.8-L capacity. Each shows a significant fuel consumption improvement compared to equivalent previous units. Mercedes-Benz says that reducing the engine displacement of the smallest version from the previous 2.0 to 1.8 L cuts friction losses and improves thermodynamics to the benefit of economy. For its new application, the supercharger has been "re-engineered" to enhance bottom end torque with clearance between the rotors and the supercharger housing reduced.

The engine goes into production later this year.

- Stuart Birch