Dyno 4: GReddy Stainless-steel headers
Pros
These stainless headers are another example of GReddy's excellent engineering and quality. They added 6 extra ponies and a few pound-feet of torque while the air temp rose another 4.3 degrees. If we had been able to test the vehicle in a controlled environment with a constant air temperature, these figures could have been even higher. To boot, the headers have a CARB exemption number welded right onto the pipe, so when Ole Smokey pops your hood, he can't bust you for an illegal exhaust piece.
Cons
Nothing here either.
Notes
Taking the stock header out can be a little tricky, especially since Honda mounted one of the two oxygen sensors right into the four-into-two section of the stock header. Wait until it all cools down, then remove the heat shield and the splashguard, unplug the harness, and drop the stock unit out as one piece. You can then easily remove the stock O2 sensor and transplant it into the GReddy unit. Neatly run the O2 extension from the back of the motor to the front and reattach it to the main wiring harness. Don't forget to wipe down all stainless-steel surfaces before running the engine, or you'll have your fingerprints permanently burned into the steel.
Tools
Ratchet, 12mm socket, 6-inch extension, 12- and 14mm wrenches, WD-40
Parts
GReddy stainless-steel 4:2:1 headers, oxygen sensor harness extension, bolts, gasket, warranty card and GReddy badge
Installation time
45 min
Temperature
Air temperature @ 78.5 degrees FahrenheitTemperature difference from previous run: +4.3 degrees Fahrenheit
2000 to 3500 HP range: -3 to 2
3500 to 5500 HP range: 0 to 4
5500 to redline HP range: 3 to 6
2000 to 3500 TQ range: 0 to 2
3500 to 5500 TQ range: 1 to 4
5500 to redline TQ range: 2 to 4
Peak Horsepower: 118.9
Peak Torque: 99.9