Project OSV is still being a problem child. In spite of a host of changes designed to improve airflow through the engine, our Alero continues to deliver just marginally better quarter-mile performance than it did in stock form. After installing an adjustable timing control and bumping spark lead to 32 (maximum spark lead with the stock calibration is 28), we were able to squeak into the 15s with a 15.926-second run. That was accomplished with an engine that was still warm from the drive to Silver Dollar Raceway. After letting the Alero cool off for a few hours, we made a 15.763-second pass (at 87.05 miles per hour) and thought Project OSV was poised to take on and embarrass all but the most highly modified Hondas. Unfortunately, we haven't been able to duplicate the 15-second performances in naturally-aspirated form.
Since we weren't having much luck convincing the engine to display its enhanced power production capability, we decided to at least make the Alero look faster. Like most current production vehicles, Aleros have a stock ride height setting that's more appropriate for a 4x4 than a sport compact. With some vehicles, cutting a half or a full coil off the stock springs is an easy and inexpensive way to lower the center of gravity. But the Alero's coils are not concentrically wound, so if a spring is cut, it won't seat properly in the chassis or on the strut (depending on which end is cut). The stock springs are also coated and the official General Motors service manual advises that any damage to the coating could lead to "premature spring failure."
Another relatively painless way to lower a vehicle is to simply replace the springs-provided appropriate "sport" springs are available. Considering that the words "Alero" and "high performance sport compact" are not commonly used in the same sentence (in spite of our efforts to change that), the prospect of finding appropriate springs was probably going to be grim. But an e-mail to partsforyourcar.com (a sister company to grandprixstore.com) was answered with encouraging news. Not only were Eibach sport springs available for the Alero, partsforyourcar.com had them in stock.
As is the case with other GM front-wheel-drive vehicles, installation of sport springs is relatively easy. Both front and rear suspensions are of the strut persuasion which means the spring is captured between a seat on the lower part of the strut body, and bracket that's bolted to the top of the shaft. The bracket is attached to the chassis with three bolts and the strut is connected to the knuckle with two bolts. Undoing those fasteners allows the strut/spring assembly to be completely removed. Then, with a spring tension contained by a spring compressor, the retaining nut on the top of the strut shaft can be easily removed with an impact wrench. (Use of a serious impact wrench, or a l-o-n-g breaker bar, is also required to loosen the strut-to-knuckle nuts.)
After the stock springs have been removed, the sport springs simply slip into place. With the spring properly positioned in its seat, the top bracket and shaft nut are reinstalled, and the strut is then ready for reinstallation. Before removing either a front or rear strut, it's advisable to scribe the knuckle so the strut can be reinstalled in its original position. When springs are changed, this is simply a short term proposition to keep caster/camber settings from getting too far off the mark; the ride height change that results from installation of non-stock springs requires a complete wheel alignment to ensure proper suspension geometry.
Upon completion of the spring swap, we took the car to Chuck Palmer of Friends Tire and HiTech Service in Loganville, Ga. for the necessary wheel alignment. Friends uses a computerized system to align all four wheels, assuring that caster, camber, toe and thrust angle are accurately set. In addition to aligning the wheels, the crew at Friends also mounted a pair of 15x8-inch Mickey Thompson ET Drag slicks on American Racing 15x7 Estrella alloy wheels.
The approach to improved starting line traction is somewhat different with a front-wheel-driver than with a vehicle that propels itself with its rear wheels. Since changing the axle ratio is such a chore, it has become standard practice to install slicks that are of considerably smaller diameter than standard street tires. The M/T slicks measure a mere 22 inches in diameter, as opposed to the 24.5-inch diameter of the stock tires. The smaller tire has the same effect as switching to a lower ratio (higher numerically) ring and pinion. So in addition to improving quarter-mile performance by virtue of a sticky tread, the slicks also offer a gearing advantage.
At least that's the theory. At the track, it didn't work out quite that way. (Not surprising, given our history with other modifications.) The shorter tires did make it necessary to shift into 4th gear well before the quarter-mile mark and we tripped the finish line lights with the tachometer indicating just over 5000 rpm. (With the stock tires, ETs and mile per hour readings were best with the transmission left in 3rd gear, which had the tach indicating approximately 6000 rpm through the lights.) But instead of improving, trap speed decreased and elapsed times remained unchanged. On this occasion, the best ET of the day was 16.182 at 83.71 miles per hour with street tires, and 16.186 at 81.52 with slicks.
Since all else had failed, we decided it was time to see how the slicks affected the Alero's performance with nitrous oxide. When street tires were mounted, we had to launch the car without a nitrous assist and then switch on the Nitrous Express system after the car was hooked up and rolling. But with the ET Drag slicks on the front wheels, we could launch with the system switched on. The slicks, combined with a bump in nitrous system jetting to 75 horsepower, resulted in the car's best-ever 60-foot and quarter-mile performance. After clicking off the 60-foot clocks in 2.135 seconds, the Alero charged through the quarter in 14.305 seconds, hitting a trap speed of 93.83 miles per hour-an improvement of 1.88 seconds and 12.3 miles per hour.
So the search for naturally-aspirated horsepower goes on. Based on the performances of other Quad Four-equipped vehicles, our Alero should start clicking off 15.50s on the motor and should be in the 13s with a bit of juice. With any amount of luck, we'll have some answers next issue.