I'm considering getting a VAFC for my 99 civic ex. a few things bout the car; aem cai w/bypass, dc sports 4-1 header, bosal muffler. There's not all that much done to the car, but i was wondering if the vafc would make a noticeable difference in horses. I would of course have it professionally installed and dynoed properly. How much power could i expect. will fuel econonmy get worse, better, or no difference?