Downs Ford Motorsport volunteered Shay Varrone's '10 Shelby GT500, which is armed with a F
In 2005, Ford released an entirely new Mustang from its chassis to the drivetrain, and its popularity is amazing. Under the hood, most people focus on the improved modular motor with its three-valves-per-cylinder and variable camshaft timing. As you move to the Shelby GT500, the attention turns to its supercharged 5.4L and four valves per cylinder.
The combination of those powerful engines with the stellar retro-looks provided a combination that has been a huge success for Ford Motor Company. Once you get past the hype of the new engine configurations, you notice a system that is a huge departure from the norm-the drive-by-wire throttle body.
Drive-by-wire technology removes any physical connection between the gas pedal and the throttle body blades. The system relies on a sensor on the gas pedal to alert the ECU of the throttle position. The ECU then signals an electronic motor, which actuates the throttle blade(s) appropriate to driver demands.
Another benefit of the new throttle body is a healthy sized dual-bore inlet. The Three-Valve mod motor throttle body has two 55mm bores, while the Shelby GT500 comes with a twin-60mm setup. Both are far more generous than the old-school 5.0L pushrod engine, which used an anemic single-bore 55 or 60mm throttle body.
The large twin-bore throttle body on Three-Valves has proven to be quite reliable and sufficient in naturally aspirated, centrifugal supercharged, and turbocharged applications. We have seen little gains in those combinations by adding a larger throttle body, but that story changes when moving to Roots- and twin-screw-style superchargers. It's been proven time and time again that an increase in throttle body size can make a major difference in power with positive-displacement-style superchargers. According to longtime Mustang expert, legendary Pro 5.0 racer, and owner of L&M Airflow Systems Jim LaRocca, "The less pressure drop you can put in front of the blower, the more power you can gain."
As the popularity of Roots- and twin-screw superchargers increased, so has the need for bigger throttle bodies. It's not uncommon to see single-bore units that are well in excess of 120 mm and upwards of 160 mm. Those sizes certainly offer very little restriction on today's massive twin-screw blowers, but there are some drawbacks to the single-bore units and other aftermarket throttle bodies.
In 2005, Ford turned to drive-by-wire controls for the blades in the throttle body. The EC
L&M Airflow throttle bodies use Delrin plastic gears to create smooth and trouble-free con
Minkin and LaRocca talked about the importance of airflow without turbulence. The L&M thro
Due to the drive-by-wire technology, swapping a throttle body usually requires re-tuning the ECU. Tuning is necessary to calibrate the driver/computer demands to the amount of airflow needed or required by a throttle body that is different from stock. For example, if the computer doesn't know a larger-than-stock TB is installed, it will simply open the TB based on the driver's throttle position. In reality, the throttle body will now be flowing more air, and greater acceleration than is desired can occur.
Of course, re-tuning adds more cost and increases the time needed to modify your Mustang. However, L&M Airflow Systems, a new company formed by Jim LaRocca and Herman Minkin, has released a new line of dual-bore throttle bodies that require no additional tuning, and each offers significant airflow for better performance. "We didn't originally design the throttle body to start selling it-my partner, Herman Minkin, and I made a couple for ourselves," said LaRocca. This "fun" project turned into L&M Airflow Systems. "People started asking if we could make these new throttle bodies available to those that need a high-flow throttle body without the additional cost of a tune. It was then that we decided to go into the business of manufacturing them."