The AEM V2 intake for the Civic Si works. In fact, if you are worried about hydrolocking your engine, the AEM V2 may be the intake for you. It produces power gains similar to AEM's published values for the CAI but you don't have to worry about hydrolocking your engine. The engine note is refined and the best I have heard on a K20A3.

If you purchase a V2 for your Civic Si, we'd like to suggest that you follow our measures of insulating the the intake tube. The insulation will help reduce the heating of the intake tube and intake air when driving at low speeds after radiator fan kicks in. Next month, we will dyno the car again with the insulated tube to measure the impact of the insulation.

There was a drop in torque and power below 4000RPMs, but for a track car, this loss of torque and power should not be an issue since the RPMs will be kept above that point for the majority of the time. Driving around the city, the loss of torque is easy to feel. The car feels slightly sluggish below 3000RPMs, but over 4000RPMs, the engine frees up. We would like to find out why the engine lost torque below 4000RPMs. When we test the Hondata user programmable ECU, we will try to see if we can tune out this loss.