Tune and Test Pontiac Firebird LS1 Build - LS1 Power Plan - Pontiac Tech

"After the engine is started again, I reference our extensive database of custom tunes and create one that will generate maximum safe power. Depending on the camshaft and components, we generally shoot for wide-open throttle air/fuel ratios between 12.5 and 12.8, with total timing in the 24 to 28 degree range. Stock LS1s as a rule usually have 24 degrees of timing and an air/fuel ratio ranging anywhere from 12.1 to 13.1, with around 12.4 as the average.

"For the initial dyno pull, I put in 24 degrees of timing and the air/fuel ratio registered at 11.7. Although the total power was 377.3 and 362.1, we knew that additional changes to the timing and fuel would generate better power.

"Once the air/fuel ratio is in the range that I am looking for, I adjust the timing and fuel until the engine first starts to register knock and then either add fuel or reduce timing so that it can generate maximum power without easily producing knock when the engine is heat-soaked.

"After a series of adjustments, I ended up pulling out a total of 6 percent fuel from 3,200 to the new redline of 6,800 (stock 6,250) and adjusted the timing ramp to be more aggressive, but retained 24 degrees." See the Dyno Testing section for the results.

Dyno Testing & Results
Testing of the WS6 '00 Trans Am was performed on Real Performance Motorsports' Dynojet Model 248C. It's capable of measuring up to 1,200 hp and is optioned with the above-ground kit and the Commander wide-band 02 sensor so air/fuel ratios can be charted. The barometric pressure, air-inlet temperature, and SAE correction factors for the runs are listed below. Peak and average horsepower and torque are the result of dyno pulls recorded between 3,800 and 5,800 rpm for the baseline, and 3,900 and 6,200 for the Comp Cams configuration.

Test Parameters
Baseline
Inlet-air temperature 101.0 degrees F, barometric pressure 29.20, vapor pressure 0.035 inch HG, correction factor 1.01.

LS1 Power Plan Part I
Inlet-air temperature 72.3 degrees F, barometric pressure 29.97, vapor pressure 0.091 inch HG, correction factor 0.97.

LS1 Power Plan Part II
Inlet-air temperature 77.1 degrees F, barometric pressure 29.72, vapor pressure 0.15 inch HG, correction factor 0.99.