2006 Honda Civic Si, Part 2

The Verdict

We managed to coax more power out of K20Z3 engine by turning our attention to efficiency, both in exiting exhaust gasses and incoming air flow. Additonally, the computer reflash helped maximize the amount of usable power and prevented the adaptive factory ECU from absorbing the power gains. Since two headers were tested, you have two options that we’ve tested to choose from when planning your own build – whether that’s a street-level performance ride or an all-out competition vehicle.

Next Up

In the final installment of the Civic T&T, we’ll look into further increasing the cylinder head air flow with an aftermarket intake manifold as well as checking out cylinder head porting options and a final reflash of the ECU to completely maximize the power production of the hard parts. Stay tuned.

The Bottom Line

HP Level HP Increase % Increase Total
BASELINE 205.0
Test 1 Vibrant Header 217.6 12.6 6.1% 12.6
Test 2 Vibrant Header w/Cat 213.9* 8.9 4.3% 8.9
Test 3 Drag Cartel Camshafts 222.8 8.9 4.2% 17.8
* * * * *
FINAL POWER 222.8 10.3% 17.8

* TEST 2 comparison is to baseline, not to TEST 1