home fabricated aero bits -materials?

[DelSolBurrow]

I see a few of you guys down there running with what looks to be plex-glass wings or diffusers...? is that all it is, cause I went to look at some today and it is very very flexible. so what exactly are you guys using? any help would be great thanks.

[woodrufj]

Probably thicker than what you were looking at. Common stuff at home depot is like 1/16 to 1/8 inch. Spoilers used are often 1/4 or better. Then they're braced in several spots too.

Jay W
505/287 Dakota

[actor]

Carbon fiber, Kevlar, foam cores, with various combinations of those materials here. Bracing is mandatory for rear spoiler on my car.

You're asking a very broad question; best to take a look at the cars in person, and see how we do it. I'll be down for the SCAT event in Feb. if you want to take a look @ my car and ask questions/take pics.

Bill Schenker

[rjung]

I see a few of you guys down there running with what looks to be plex-glass wings or diffusers...? is that all it is, cause I went to look at some today and it is very very flexible. so what exactly are you guys using? any help would be great thanks.

The spoilers that look like translucent plexiglass probably are, in .375-.25" like what Jayson said. Also you can look for Lexan (polycarbonate) sheet which is less brittle. I haven't seen any wings or diffusers made from plastic sheet stock though.

Bill's aero bits are real racecar tech.

If you are interested in reasonable carbon or alum. wings or splitters let me know.

Rick

[DelSolBurrow]

ok I'll try to be a little more specific. I m trying to make a some what functional front lip/splitter, front diffuser or some combo of the 3. I knew for sure bracing was needed but I think I was looking at stuff that was too thin, cause what I was looking at would need some insane bracing. If I was looking to place a fairly decent size plate under and sticking out of my front bumper a little, how thick should the plexi be? or what would be the best material for some one on a budget?

[dwkfym]

I don't have any real life experience with it, but like mentioned before, thicker material sounds good.

If you were very serious I'd do what the Aero students do; foam core, dry CF or fiberglass over the foam..the composite stuff would also be structural. they come out very light, very strong. You can adjust the flexibility with the CF, since you aren't building plane wings I think you'd want as stiff as reasonable. For the foam I think they use construction styrofoam from Dow company; they are surprisingly strong and light. You can cut it as if it was extra light balsa. Any rivets used to hold down supports are supposed to be as flush as they can (I think they have a name since its an aircraft application) but I don't think it matters that much.

We did some tests on the foam for usage on an driver's restraint type application. it is definitely good material for aero parts- though we canned the idea of using it for a restraint (padding)

The material you are looking for is Dow High Density Construction Styrofoam (Blue). They come in different compressive characteristics ranging up to 100psi.. I think the lowest and the second lowest one they offer is good to go.

You could look up dry CF processes on the internet and you can do things to make the foam the mold itself; I think it is definately doable in a garage. You may have to be creative with manufacturing since you probably need to attach sections of foam to make it long (wide) enough..

I don't think this is exactly the answer your are looking for, but this is what I've been exposed to the most. Its all textbook knowledge and word-of-mouth from people I do our project with, so if I am wrong please someone correct me.

If you can't find thicker plexiglass, I think gluing them together and painting over them would work well too-though I think that might add marginal weight. I am not sure if you should round off the edge or have it as sharp as you could. It shouldn't be square though.

I think what you are trying to achieve is a high pressure area that gathers between the front bumper of your car and the splitter by blocking the air that hits your bumper and goes under your car. I suppose you can also have it angled down so it increases such effect- but check with someone for that (maybe with the creator of splitters of death)

The ultimate thickness of your splitter would, i would venture to guess, matter on your design. How much bracing you would use, etc etc. I think 0.25 that was recommended here is a good start..

If I had the money and it were up to me, I would try 2 different pieces; one you think is slightly too thin, other that you think is slightly too thick. And then I'd optimize with the third piece while leaning on the safe side. Of course, if you really wanted to get serious, you would calculate everything and run simulations or a lot of tests.

Now, another compromise I can see is the thickness of the splitter vs # of bracings.. it would be up to you to figure out the lightest combination.

Sincerely,
Jerry
-unqualified business student

[DelSolBurrow]

wow, Jerry thank you for the very lengthy reply full of a lot of info! I will be looking into a lot of what you mentioned.

[nalbar]

I'll be down for the SCAT event in Feb.

Bill Schenker


There is no SCAT event in Feb.


nalbar

[Cullen]

I believe APC makes some killer stuff.

[DelSolBurrow]

I believe APC makes some killer stuff.


yes, there stuff is the look I am going for...lol

[AlexT]

IIRC, in one of GRM mag articles, some use plywood or masonite as splitter for a Sentra SER. It worked except that splitter gets trashed really bad everytime the car takes on some off-road excursions.

[actor]

There is no SCAT event in Feb.


nalbar

Oops! I meant the March event!

As far as how thick to make it, and how much bracing to use, a lot of that depends on how ridged and solid the area you are mounting the Splitter/spoiler to is.

[DelSolBurrow]

What would be the bare minimum for a splitter to stick out to be at least some what affective?

[D Rex]

Here is a couple links to check out on your splitter research.

www.specialprojectsms.com/index.php?categoryID=30

www.roadracegear.com

[DelSolBurrow]

sweet links, thank you

I found this as well

http://www.e30m3performance.com/myths/splitter/splitter2.htm

[rjung]

yes, there stuff is the look I am going for...lol

APR is the company. I'm an APR dealer and can help you out with a good-guy solo price.:D

It would most likely be less cost to get one of their splitters.

[rjung]

ok I'll try to be a little more specific. I m trying to make a some what functional front lip/splitter, front diffuser or some combo of the 3. I knew for sure bracing was needed but I think I was looking at stuff that was too thin, cause what I was looking at would need some insane bracing. If I was looking to place a fairly decent size plate under and sticking out of my front bumper a little, how thick should the plexi be? or what would be the best material for some one on a budget?

If you decide to make one, plex (acrylic) would shatter in a splitter application. ABS, PC, PP, Nylon or PE sheet would work better, but still not be optimal in terms of wt., stiffness and heat tolerance.

[MX5bob]

Also be sure to check the rules about how far out it's allowed to be. In SP for example, it can't extend further out than the front-most portion of the body work.

That's not really a fair rule because the front shapes of cars are very different. Bill S. gets a pretty good amount out front because the Miata's lower body work sits a few inches back. But if you had certain of the 1980s era 3 Series BMWs, you'd have much less because the front body work all lines up in a nearly dead vertical plane. :p

But it's a simple rule to scrutinize in impound compared with measuring square inches of surface.