On their Roadkill video trips, David Freiburger and Mike Finnegan are used to buying vehicles of questionable repute, and putting them to the test. By Roadkill standards, the Chevrolet Monza they bought in Ohio was a relative gem. Factory-equipped with a 305 V-8 and a four-speed manual, the disco-era fastback proved itself capable of burnouts and powerslides on slick pavement, which was good enough for the Roadkill team. But the true reason for buying the Monza was to test the theory of if it was possible to make more power by adding leafblowers to the intake stream.
However, some fine-tuning of the valvetrain, and the installation of a 650 CFM double-pumper carb lying around the shop yielded the biggest power gain, going from 144 to 193 hp. With the leafblowers not creating the level of power they expected, some reverse-engineering revealed that the blowers going full-blast were causing some reversion in one of the blowers, essentially creating a boost leak. With an upstream ball-valve installed, the engine was able to take full advantage of the airflow when it had a greater appetite for air.
With the tubing and bypass valve installed, and with Lutz’s shop swapping out the tired 305 for a beefier 350, the two were off to the Ohio Mile to see how fast the sleek 70s icon would run. All-out, the Monza ran an impressive 139.84 with Lutz driving and leafblowers at full blast. Not bad for a total of $4600 invested, $3000 in the Monza, and $1600 in leafblowers.
Check out Roadkill every fourth Friday on the Motor Trend Channel!