tring to decide on aluminum or carbonfiber driveshaft.but my car is lowered and i dont want it to rub driveshaft.anyone know if it will rub on the body?it is 3.75 in dia.-frpp aluminum is 3.5.
Unless your making crazy amounts of power, there is no reason for a carbon fiber drivshaft. Your rear end will probably blow before an aluminum driveshaft....
No, you will not have problems with rubbing using either driveshaft. I've got quite a bit of room between my driveshaft loop and the shaft and have yet to scuff the bottom of the car. Mine's dropped roughly 2.5".
In regards to carbon fiber...it is considerably lighter, and more expensive than aluminum. In regards to whether or not a lighter driveshaft is "needed", that is a bit controversial and will depend upon its application and why you're using it. There are quite a few folks that use a lightweight driveline to reduce engine drag, not so much because they need it in a high horsepower/torque vehicle.