What purpose do these serve? Found on aero 84-90 bird side ground fx. I recently took mine off because they were completely warped.

 

Visually they help hide undercarriage mechanicals from view.

Aerodynamically? They would help with wind entering the underbody from the sides.

 

IIRC their is a thread about them being straitened out.

 

It's possible they add some aerodynamic flow alignment, but pretty unlikely considering how unaerodynamic the rest of the undercarriage is. Much more likely they are just there to hide the undecarriage, especially the exhaust. They are easy to straighten with a heat gun. They mostly get warped because they are mounted with the same screws as the gfx and they get twisted by the screw torque. To prevent that, they should be held straight when torquing them down and don't over torque.

 

Quote:
Originally Posted by blktransam View Post
They are slightly warped, so they don't look very cool when looking under the car....

What I did to mine, when they started to "look warped", was I took them off and placed them on a 2x4 lengthwise, covered them with a damp towel and took a, believe it or not, a steam iron on steam setting and ran it along them and pressed them back into shape. Then remount. Looks brand new!