Why an Olds Alero?" That's the most frequent response when I mention GM High-Tech's OSV project car. That is, unless the responder has spent some time behind the wheel of an Alero. In that case, the response is usually, "Neat. I drove one of those the other day. It's a great car-it should be a great project." Clearly, the response lines are divided between the people who have driven an Alero and those who haven't. And that is undoubtedly one of the causes of Oldsmobile's problems; not enough people realize that the division has a number of outstanding products, many of which are just waiting to deliver an impressive payback on performance modifications.
The prospect of building a hot rod Alero came about during a discussion with Vince Muniga, then a member of Oldsmobile's public relations department. Vince was a bit frustrated that so many Oldsmobile models were not receiving the recognition they deserved. "We've got some really great cars, but nobody seems to realize it," he lamented. Having recently driven most of the models in Oldsmobile's product line, I had to agree. And although the exhaust note and horsepower of the Aurora V8 was more to my liking, I found the prospect of raising the performance level of a four-cylinder, five-speed Alero particularly intriguing.
Within the GM divisional hierarchy, Oldsmobile had been positioned as the "Import Fighter" division. The Alero is clearly targeted at the same sport compact buyers who find the Acura Integra, Honda Civic and Nissan 240SX appealing. Much of what drives the demand for these cars is the "fast and furious" performance of the modified versions that show up in ever-increasing numbers at drag strips around the country. Domestic vehicles like the Alero have just as much (if not more) performance potential as their imported counterparts; they simply haven't yet developed the same type of performance image.
Vince and I agreed that a modified Alero would be a kick-ass alternative to an import, while simultaneously giving the Honda/Acura contingent some well-deserved heartburn at the drag strip. Discussions continued over the next few months between me, Vince and Doug Schumacker (Alero brand manager). At long last, all the paperwork was completed and, shortly thereafter, I began turning wrenches on a bright red Alero coupe.
Like all 2001 and earlier four-cylinder Aleros, our project car is powered by a 2.4-liter version of the four-valves-per-cylinder, dual overhead cam Oldsmobile Quad Four engine. Rated at 150 SAE net horsepower, the engine is mated to a Getrag five-speed transmission. The Quad Four has served as GM's high tech four-cylinder engine since 1988, when the production version debuted in the Olds Calais. At the time, it was the first new GM gas-fired engine to be released in five years and it featured a number of innovations including direct spark (coil-on-plug) distributorless ignition, a Hemholtz-tuned intake system with 16-inch long runners, cross-flow cylinder head and the highest specific output (1.1 horsepower per cubic inch) of any naturally-aspirated engine produced in North America. In experimental turbocharged form, the Quad Four produced over 1,000 horsepower and propelled the Olds Aerotech test car to speeds of over 220 miles per hour.
Even though the engine has undergone numerous changes over the years, the current 2.4-liter version has the same 150 horsepower rating as the original 2.3-liter model. On the other hand, the Getrag five-speed is a recent addition to the Quad Four powertrain menu. That addition dramatically changes the driving experience when you strap yourself in behind the wheel of an Alero. With only 150 horsepower propelling a 3,000 pound vehicle, acceleration certainly isn't blistering, but the engine's excellent throttle response combines with a smooth shifting five-speed and competent suspension to provide an enjoyable driving experience.
Subjective evaluations aside, every project has to start with a solid baseline. To that end, we took the car to Silver Dollar Raceway in Reynolds, Ga. for a few quarter-mile excursions. For anyone doing serious testing, Silver Dollar Raceway is hard to beat. Owner Ed Swearingen and his staff do everything possible to help and they keep the track surface in excellent condition.
In spite of the fact that my 11-second Camaro has no traction problems and consistently daylights the front wheels when launching at Silver Dollar, the Alero produced a surprising amount of wheelspin. In retrospect, we should have expected as much. Street tires, combined with front-wheel-drive, isn't the best combination for hard launches. Obviously, traction challenges will be an integral part of this or any other project involving a front-wheel drive vehicle.
Experimenting with different starting line techniques resulted in varying amounts of wheelspin and a wide range of 60-foot times. Gear changes-or the lack thereof-also proved to have a significant effect on performance. Even though the tach needle was probing the depths of the red zone, the transmission was left in third gear through the lights; shifting into fourth gear invariably had a negative effect on elapsed time and trap speed. Ultimately, releasing the clutch while rolling into the throttle, and leaving the transmission in third gear, produced the best performance-a 2.421-second 60-foot time and a 16.437-second ET with a speed of 84.42 miles per hour.
The second part of our baseline testing involved a trip to Engineered Performance in Smyrna, Ga. for a few runs on the company's Dynojet chassis dyno. With Ed Senf (Engineered Performance's dyno specialist) handling the controls, the stock Alero cranked out a broad, flat torque curve. The maximum reading (at the wheels) was 145 lbs.-ft. and the curve stayed above 130 from 2500 to 5000 rpm. Horsepower peaked at 5700 rpm with a reading of 134. That represents a drivetrain loss of approximately 11 percent, which is well within the accepted 10-15 percent range.
Having worked with a number of other late-model front-wheel-drive cars, we knew the exhaust system was going to need some romancing before the engine could live up to its true power potential. So before heading to the dyno, we were sly enough to contact Random Technology and convince the company to build a prototype high-flow catalytic converter. And as soon as Ed finished his baseline dyno assault, we bolted on the Random high-flow cat and strapped the Alero down for a few more blasts.
Previous experience with a V6-powered Alero indicated we'd see impressive results. That car responded to a high-flow converter with a .16-second and 1.04-mph improvement in quarter-mile times. (That equates to an increase of about 10 horsepower.) Unfortunately, the Quad Four didn't respond as well. Increases at peak readings were only two horsepower and less than one lbs.-ft. of torque. Between 2200 and 3600 rpm, torque increases ranged from two to four lbs.-ft. but elsewhere, the horsepower and torque curves of the before and after runs crisscrossed each other. Average torque from 1900 to 6500 rpm was 101.7 lbs.-ft. with the stock catalytic converter and 103.1 with the high-flow model. Average horsepower over the same rpm range was 130.4 and 132.0, respectively.
Obviously, other flow restrictions were roadblocks along the highway to horsepower. Where are those roadblocks? That and other questions will be answered in Part 2, in the next issue of GMHTP.