Tune it Power is everything
| 2500 to 3500 HP range: -1 to 2 | 2500 to 3500 TQ range: -1 to 2 |
| 3500 to 5500 HP range: 1 to 3 | 3500 to 5500 TQ range: 1 to 5 |
| 5500 to red line HP range: 3 to 8 | 5500 to red line TQ range: 3 to 5 |
| Peak HP 147.3 | Peak TQ 153.7 |
Pros
The factory header system utilizes a built-in primary catalytic converter. Using the Alphawerks header eliminates this catalytic, leaving you with the secondary cat, which is still attached to the factory b-pipe. A gain of 8hp was achieved from 5700rpm to redline and 7 ft-lb of torque improvement was recorded at 3300rpm and once again at 5600rpm, which stayed constant until redline.
Cons
Removing the factory heat shield to access the factory O2 sensor proved to be a bitch. We notched the heat shield where the factory bolt protruded to easily remove the cover and gain access to the O2.
Notes
Alphawerks provides a detailed schematic on how to install the O2 simulator which is sold for $50 dollars. The three-wire black box is tied into the factory ECU and tricks the factory ECU while eliminating the dreaded engine check light. In less than 15 minutes, we used two butt connectors and a t-splice to connect the wires. We reset the factory ECU by disconnecting the battery for two minutes. The O2 simulator worked like a charm and the engine light never once reared its ugly head.
Installation time
50 minutes
Tools
12- and 14- combination wrench, 12- and 14- socket, ratchet, extension, screwdriver
| BANKROLL |
| GReddy EVO2 Exhaust | $ 599.00 |
| Injen Cold Air Intake System | $ 320.00 |
| Alphawerks Header | $ 600.00 |
| O2 Simulator | $ 50.00 |
| MSRP Total | $ 1569.00 |
| CONCLUSION |
| | HP Level | HP+ | TQ Level | TQ+ |
| Baseline | 140.5 | | 149.4 | |
| GReddy EVO2 Exhaust | 144.0 | 4.5 | 151.8 | 2.4 |
| Injen Cold Air Intake System | 147.3 | 3.3 | 153.7 | 1.9 |
| Alphawerks Header | 154.6 | 7.3 | 157.3 | 3.6 |
| Final | 154.6 | 15.1 | 157.3 | 7.9 |
Temperature
77.6 degrees Fahrenheit
Temperature difference from previous run: +1.5 degrees Fahrenheit
Parts
Header, O2 simulator, instructions
Conclusion
Using three simple to bolt-on power adders we were able to gain 15.1 wheel hp and 7.9 lb-ft of torque to the 2.4-liter Scion. This was an impressive gain when considering how difficult it is for most OBDII vehicles to produce ponies without the air of a forced induction kit or internal engine work.
Tune it Power is everything
| 2500 to 3500 HP range: 0 to1 | 2500 to 3500 TQ range: .05 to 1.5 |
| 3500 to 5500 HP range: 1 to -1 | 3500 to 5500 TQ range: 1.5 to 0 |
| 5500 to red line HP range: 3 to 4 | 5500 to redline TQ range: 1.5 to -0.2 |
| Peak HP 154.6 | Peak TQ 157.3 |