Seeing as im new to accord modification and whatnot... im not exactly sure that what im saying has any validity, but feel free to correct me. One day while going through my 2000 Accord DX's manual, I noticed a chart that listed the compression ratios for the F34A series. The F23A5 (in the DX model) had a ratio of 8.6-8.8:1 i think, and the F23A1 and F23A4 had about 9.2:1. I do not think the engines are that much different after going through the Haynes manual, so I am guessing that the basic horsepower differences are in the compression ratios between the engine models. Does anyone know if there are any basic mechanical differences that result in the higher compression or something else in the F23A1/4 engines, and if so/not... then any ideas on how I might get my engine to perform on about the same level? Any input would be appreciated!