HEy, its a dumb *** question, but i drive a US lancer. i got an evo 8 spoiler replica, and its ABS plastic w/ no carbon fiber. It vibrates on the freeway or at speeds of 55mph and up. How come the real evo 8 spoiler doesnt do this? is this b/c It is made of a different material beside the carbon fiber? perhaps fiberglass??
-chris

 

Everyone seems to think that carbon fiber is only for looks. It does look good, but it real reason for existance is strength to weight.

Carbon seem like it would be very weak, (Pencil lead, coal, so on...), but no one would say that about Diamond. Diamond is another form of carbon, with a 3D linking of the carbon atoms.

Carbon fiber is grown in such away to create a Diamond like structure along its length. This gives carbon fiber very high tensile strenght. Much greater than glass and much lighter.

Your ABS spoiler is not as stiff as the Carbon FIber one because it doesn't have the benift of the fiber reinforcement. Even glass fiber would make a huge difference.

Due to the lower stiffness the ABS spolier deflects more under the same load. So you see this when you drive down the road.

ABS is a good plastic, but a composite structure is greater than the sum of its parts. You don't see concrete used without rebar, for the same reason.

Some aircraft are trying fiber reinforced thermoplastics (ABS & Others) but that is very high end fighter jet stuff.

You might try fitting an aluminum or steel tube into the inside of the airfoil from one support to the other if you can get to the ends. To get increased stiffness you need as much depth to the shape as possible, plates won't help much need to be a closed shape.

The STi spoiler is said to do the same sort of thing.

 

Also, I'm sure that whomever made that spoiler, didn't take the time in the wind tunnel and get the angle and aerodynamic profile as exact as mits did.

 

maybe you're not going fast enough to have that spoiler work.