Originally Posted by WackyRicky
You can make a functional under panel out of any material that is strong enough. I've read an article in a Japanese car magazine, in which they tested under panels made out of several different materials like sheet metal (aluminum, or was it stainless steel?), plastic, and even plywood and they all yield the same result (when it comes to lessening turbulence under the car). I can't remember exactly how they conducted the test tho. Anyways, with that being said, you probably want to stick with metal or CF because of heat and other stuff. (plywood will rot and you don't want to drive around with rotten pieces of wood under your car!)
:chuckles: Yeah, plywood is definitely
not a good choice for underbody panels..
From a cost-benefit standpoint, it sounds like aluminum or stainless steel sheet would be best. It will manage heat well and is easily stamped, cut or welded.
A word of caution, though: If anyone is roused to action and decides to go with aluminum, be sure to add rubber isolators between the aluminum panels and the steel chassis. You don't want electrolytic corrosion to set in.
While a CFRP undertray would look fantastic, it'd be a bitch to repair if it were to crack.
h: