I've heard from couple people that when you add a cold air intake and exhaust (perhaps headers, cat and muffler) that you need to tune the car in order for these modifications to perform otherwise it can ruin your motor?? Is this true? I have a S5 gxl (n/a) and i've been wanting to add some mods. I know a lot more about 240s than rx7s now that ive spent couple years driving 240s. this is my first month with an rx7 and i duno where to start. help..