Help me pick the best material for underbody panels.
 

I want to replicate a similar underbody panel like the TRD Griffon but i'm stumped on which material to go with. Just looking on McMaster, Alloy 5052 or Titanium (grade 2) would be under $60 for a sheet that should be good enough. Only bad thing with titanium it seems is cutting and drilling it would be hard. I would have to drill holes for the screws/caps to fit and also I would have to cut a small area for the cat. Taking it to a professional with proper tools is possible but i'm not sure how many pros deal with titanium.

http://i2.photobucket.com/albums/y42...5CAAB164-1.jpg

What about cooling?

I say go with a durable plastic. Rust proof and probably lighter then metal. A plastic like what you find in truck liner

It will only cover the cat and res. Actually it will need to be cut around the cat since it drops low or I will have to hope a HFC will clear it.

I was thinking of some sort of plastic but I'm not sure which one would be able to handle very high temps since the exhaust tubbing and car could melt the plastic if its not up to the task

Delrin may qualify.

If I were going to go with a sheet metal it would probably be aluminum. Honestly, titanium is going to be a huge hassle to work with. If you insist on it, by all means make the aluminum one first. Once you're done massaging the dimensions and such, take the aluminum pattern and a sheet of Ti to a fabricator who can work with it and have them do the final build.

Then get a vendor account! :P

I would love to have something like these if only to keep all the salt away from the undercarriage. I would say that a plastic could certainly work, but the heat would be a factor... Hell, figure out what the JDM ones are made of and copy off them. Probably a fiberglass or glass reinforced plastic?

Use plastic if you can. Cheap, easy to work with, effective, and lightweight. Just keep it away from heat sources and you'll be fine. If you want to go a more expensive route, I'd use basic sheet metal or aluminum. Titanium would be a waste of money, unless you're just trying to have something to impress people with (which it probably won't...people would be more impressed with the fact that you made it yourself than the material you chose to use)

What’s the material of the JDM under panel (black one)?
Thanks.

Probably injection molded plastic.

I'd go with Ti, if it's available and as/close to affordable as aluminum. If it's significantly more, I'd go with aluminum.

This is a pretty straight forward affair. It shouldn't be as hard as everyone is making it.
1. Get under the car and make a card board template.
2. Take cardboard template to a sheet metal fabricator.
3. Crack a beer and profit?

You should be able to locate a sheet metal fabricator by contatcing any HVAC construction company. Either they will have one in-house or a vendor they can reccomend.

This looks to be a fairly straight piece(s) with only a few holes in it.

Hmm..I know someone in plastics manufacturing who has mad some one off things for his home. I wonder if he could make a run if I got some specs. I'll see, because I could make a mock up with vent/cooling.

You want something stiff enough (or something that is mounted securely enough) to not start to resonate with airflow, otherwise you're really taking a step backwards. Just be aware of that when you're going through the process.

This needs to happen. Full flat underbelly - because race car!

I was thinking about using dibond or alumalite. I just don't know how much of an air gap I'll have between my exhaust components and the panel.

Titanium might be stronger than aluminum, but it is also 60% heavier (for the same thickness).

I don't think you want to work with titanium, It's difficult to work with, hard on tooling and expensive, several times the cost of aluminum. My first choice would be fiberglass, like the splash guard. I think someone said the forward JDM aero panels are fiberglass too. With fiberglass, you can make wood mold and relatively easily make most any shape you want. Second choice, heat resistant plastic. Third choice, aluminum. Plastic would be, bar far, the easiest material to use.

I wouldn't use Plastic...being close to the exhaust.

Look into alumalite. It's an aluminum panel with high-density corrugated polyallomer (CPA) core. Really rigid / lightweight.
You should be able to find smaller 4x4 sections at hardware stores.

Is your goal aerodynamics, or protective? If its just aerodynamics I'd use plastic. If your looking for strength go with the titanium (as long as its an appropriate grade).

Keep in mind Titanium work hardens and can be very tricky to work with.