Plus you are comparing a SOHC Vtec "B18b?" Civic Si. with the more powerful acura/honda B18c1. Thats Why the net gain in HP and Tq Is Lower Across The Board when you throw the CAI, Headers and Exhaust at it. And Nissan's Pathetic Vq25 motor in the sentra s-er are the worst of all. Every customer that owns one and does any spirited driving in that car will have the motor replaced due to oil starvation problems on a grander scale than we experience with the duratec.
However they are relatively mod happy but without a lot of support until NISMO was authorized to have factory support in the u.s..
