Conclusion
Improvements of over 0.3 second and 3 mph aren't to be taken lightly. SLP's 350hp PerformancePac proved to be a real power adder, visual appearance (underhood, underside, and outback) is an added benefit of these upgrades. In our case, considering the age of the T/A's stock plug wires, Performance Distributors LiveWires were a worthwhile addition as well.
For those who desire even more power, SLP also offers PerformancePacs for 375 and 400 hp.
| Strip Test Results |
| March 23, 2006—Temperature, 50 degrees; Humidity, 35%; Barometer, 30.15 hg |
| Run | Temp | Mods | 60-ft | 1/8-mile /MPH | 1/4-mile / MPH |
| 1 | 48° | Baseline, box-stock LS1 | 1.96 | 18.57 / 82.86 | 13.33 / 103.36 |
| 2 | 48° | 2-minute–later hotlap | 1.96 | 8.58 / 82.81 | 13.35 / 103.22 |
| 3 | 50° | SLP’s cold-air induction | 1.93 | 8.45 / 84.36 | 13.11 / 105.21 |
| 4 | 50° | Hotlap | 1.94 | 8.46 / 84.32 | 13.13 / 105.07 |
| May 9, 2006—Temperature, 65 degrees; Humidity, 61%; Barometer, 29.93 hg |
| Run | Temp | Mods | 60-ft | 1/8-mile /MPH | 1/4-mile / MPH |
| 1 | 62° | Baseline | 1.97 | 8.54 / 84.07 | 13.24 / 104.71 |
| 2 | 62° | Hotlap | 1.97 | 8.55 / 83.84 | 13.27 / 104.60 |
| 3 | 64° | SLP Loud Mouth II exhaust | 1.98 | 8.49 / 84.90 | 13.14 / 105.99 |
| 4 | 64° | Hotlap | 1.98 | 8.52 / 84.60 | 13.18 / 105.58 |
| 5 | 65° | PD LiveWires | 1.97 | 8.45 / 85.10 | 13.10 / 106.21 |
| 6 | 65° | Hotlap (hot motor, heatsink) | 1.96 | 8.50 / 84.52 | 13.15 / 105.57 |
| Parts And Prices |
| Part | Part No. | Price |
350hp PerformancePac
SLP Loud Mouth II exhaust with dual tips
SLP FlowPac cold-air system
“350HP PerformancePac” fender badges (pair) | 28020 | 725.90 |
| Performance Distributors LiveWires | C9LS1 | 85.95 |
| Tested Parts Total | | $811.85 |
This is the high-flow, washable, reusable air filter. According to SLP, "The Blackwing filter line uses a proprietary filter media called Syntec. Unlike traditional cotton-gauze filter media, Syntec's unique, random microstructure both outflows and outfilters cotton gauze." Without it, the cold-air induction system wouldn't have adequate airflow. | 
The stock air-cleaner assembly was taken off as a one-piece unit for removal of the mass airflow sensor. It took us 30 minutes to carefully pry the MAF off without damaging it or the original hoses. These parts were corroded together on this daily-driven, never-garage-kept car. |
On top is the stock baffled, restrictive air-cleaner lid. Below, the smooth SLP lid can move additional air with less turbulence and more velocity. | 
After hearing the Loud Mouth exhaust on other cars, we thought it was a little too "loud." This helped us decide to use the new Loudmouth II muffler (right). Inside, you can see the perforated pipe wrapped with sound-deadening material |
SLP's cold-air induction system with the smooth bellows (included in the FlowPac) has a much cleaner and attractive look than the stock setup. The factory MAF is the only part reused from the stock air assembly. We were pleased with how much quicker the Poncho was: over 0.2, we were only expecting 0.1! | 
Externally, you can't tell the difference between these two polished, stainless beauties. The Loud Mouth is referred to as a resonator, while the Loud Mouth II is classified as a muffler. Both are shapely, good-looking, and made to last a long time. |