well, i had the same question, but i think i know mine..umm, it depends on ur ecu, your ecu limits how high you can rev. you can get a ecu to change ur ability to rev as high as u want, but go to high and u will probably blow it. since ur in the prelude section, im thinking u have a h22, h23, or a f22, or something around there..and i have a h23 and it redline at like under 7k, but my ecu allows me to rev up to 7300 before my ecu kicks in and it stops feeding me fuel.