Dyno Results: Key Engine Parameters: Air Inlet Temperature (AIT). Maximum values are noted unless otherwise stated. Average horsepower and torque are dyno pulls recorded between 3,300 and 5,800 rpm.
| Conf. | AIT | HP | HP Gain | HP Avg. | Torque | TQ Gain | TQ Avg. | A/F Avg. |
| Stock | 90.7 | 302.7 | — | 260.4 | 316.2 | — | 302.8 | 12.7 |
| LS6 Int., TB Bypass | 93.5 | 309.2 | 6.5 | 265.0 | 319.5 | 3.3 | 306.7 | 12.7 |
| LS6, TB Bypass, and S2 TB | 94.1 | 314.0 | 4.8 | 267.3 | 324.9 | 5.4 | 312.1 | 12.9 |
| LS6, TB Bypass, S2 TB, and Lid | 93.8 | 321.5 | 7.5 | 272.2 | 330.0 | 5.1 | 317.9 | 13.4 |
| Total Gains | | | 18.8 | 11.8 | | 13.8 | 15.1 | |
Testing of the '99 Trans Am was performed at Real Performance Motorsports in Lewisville, Texas. RPM has a Dynojet Model 248C dyno that is capable of measuring up to 1,800 hp and is optioned with the above ground kit and the Commander wideband 02 sensor so air/fuel ratios can be charted.
Dyno Pulls: The "stock" configuration has a descreened MAF, an aftermarket K&N air filter, and an SLP Loud-mouth after-cat exhaust.
* Stock Test Parameters: Air inlet temperature 90.7 degrees Fahrenheit, barometric pressure 30.09, vapor pressure 0.17 in. HG, correction factor 0.99
* Stock, plus an LS6 intake manifold and TB bypass Test parameters: Air inlet temperature 93.5 degrees Fahrenheit, barometric pressure 30.08, vapor ressure 0.16 in. HG, correction factor 0.99
* Stock, plus an LS6 intake, a TB bypass, and a Shaner S2 throttle body Test Parameters: Air inlet temperature 94.1 degrees Fahrenheit, barometric pressure 30.13, vapor pressure 0.16 in. HG, correction factor 0.99
* Stock, plus an LS6 intake, a TB bypass, a Shaner S2 throttle body, and an MTI lid
Test Parameters: Air inlet temperature 93.8 degrees Fahrenheit, barometric pressure 30.07, vapor pressure 0.15 in. HG, correction factor 0.99
Cost-effective Mod! MTI Airbox...
Cost-effective Mod! MTI Airbox LIDThe factory upper airbox assembly can be improved upon in several areas. Notice the ridges cast into the top of the lid and how the entrance and exit of air into the box are squeezed down into an oblong shape. Airflow is disturbed significantly as the air enters the opening to exit toward the MAF and has to be routed to twin baffles and squeezed out of a smaller opening.
Horsepower Dyno Chart
Torque Dyno Chart
| Conf. | AIT | HP | HP Gain | HP Avg. | Torque | TQ Gain | TQ Avg. | A/F Avg. |
| Stock | 90.7 | 302.7 | — | 260.4 | 316.2 | — | 302.8 | 12.7 |
| LS6 Int., TB Bypass | 93.5 | 309.2 | 6.5 | 265.0 | 319.5 | 3.3 | 306.7 | 12.7 |
| LS6, TB Bypass, and S2 TB | 94.1 | 314.0 | 4.8 | 267.3 | 324.9 | 5.4 | 312.1 | 12.9 |
| LS6, TB Bypass, S2 TB, and Lid | 93.8 | 321.5 | 7.5 | 272.2 | 330.0 | 5.1 | 317.9 | 13.4 |
| Total Gains | | | 18.8 | 11.8 | | 13.8 | 15.1 | |