ive decided, after much research and designing, to start making my underbody aero pieces.
this will be done in a few stages so i make sure that i have my technique and fitment down.
1. Front lip chin guard. (basically a driveway guard for my current bumper)
2. Rear diffuser (axle back)
3. Front Spliter / airdam and engine tray (axle forward)
4. under body tray (between the axles)

now my car is pure black. even my APR carbon wing was color matched to the body.

so should i do the pieces in the classic Carbon twill, or in the yellow black Carbon / Kevlar?

i was leaning towards the kevlar because of its wear resistance.
these shouldnt extend too far up the side, maybe only an inch or two would be visiable from the side.

what ya guys think?

all carbon, i dont like colored kevlar

Are you building this for a stock body?
Also were you considering making more panels for re-sale?
My self and probably a few other members here and on other forums are dieing for a sick diffuser which works well with the stock rear.
Good luck, hope it turns out good.
Oh go with the kevlar, you wont see how it looks since its on the underside of the car, just go with whatever it the strongest.

Originally posted by vroom-vroom
Are you building this for a stock body? Also were you considering making more panels for re-sale? My self and probably a few other members here and on other forums are dieing for a sick diffuser which works well with the stock rear.

unfortunatly no, this is a kitted car. dont worry its not a Blitz
this was origionally designed as a one off project, however after talking to different members during the research phase, if this works out nicely i probably would expand into making some things for the 2GB stock body. (subtle yet fully functional and not $4000)

Dave, since its under the car and going to take a beating, I would go with the kevlar due to strength and longevity.

Terry

Pics of the car foggy.

Sounds tits and i dont remember ever seeing it.

"4. under body tray (between the axles)"

Oh hell yea. 'bout time someone tackles this

Originally posted by ez
"4. under body tray (between the axles)" Oh hell yea. 'bout time someone tackles this

+1

And like terry said for underbody stuff go with the carbon kevlar blend to prevent breaking

Originally posted by 2GeclipseRS
Pics of the car foggy. Sounds tits and i dont remember ever seeing it.

dont worry you havent missed any, because i've never posted any.
i always feel its "not quite done" and since im building this the way I want, i'd feel better posting and saying "look what ive done" as oppsed to the "this is my plan"

but i can throw up some teaser pics :evilgrin

haha ya i want to see this. My opinion probably doesnt mean much but if you aint going to see it really and its stronger id go with the kelvar. Always go for quality

Originally posted by Flipboi89
My opinion probably doesnt mean much

lol yeah it does, especially when i post somthing and somebody jumps in and sez "Foggy thats gonna look like ASS that way!" it usually get me to look at my project from a different perspective and possibly change things.

btw i posted my project
http://forums.2gnt.com/dcboard.php?az=show_topic&forum=92&topic_id=400&mesg_id=400&page=

Be careful with underbody trays...You can have serious issues with overheating because of the exhaust. I would try to avoid closing in the exhaust area. Mostly focus on creating parts to smooth the transitions around the suspension components.

i thought about the overheating issue as i was going throught the research for ideas.
most of the front engine rear exhaust cars i found either didnt use a center undertray section or they exhausted out the front fender.
the NSX one gave me an idea though, one version i saw used NACA ducts to route cool air into the engine bay, and another had circle vents cut out and used the Venturi principle to draw the hot air out.

so on our cars with an enclosed tunnel i would use the venturi design along with a thermal coated and/or wrapped exhaust to heep the heat in the pipe and any that escaped should be drawn off by the venturies.

course this all sounds good in theory :P so we'll see

on the VW/Audi "belly pans" they use naca ducts to get cooler air up into the engine bay.

I thought the holes for the venturi effect were right behind the radiator usually

Originally posted by RoninEclipse2G
I thought the holes for the venturi effect were right behind the radiator usually

it usually depends on the venting on the hood and the configuration of the radiator / intercooler setup.
on factory cars very few manufactures use vented hoods, so most are designed to expell hot air out the bottom of the bay (venturi effect if done correctly)

Update!!

in doing some research and talking to some different companies we have come up with designs notes that i thought you all might be intrested in incase anybody else wants to do this.

on to the info:
first off i talked to Kognition Design (http://kognitiondesign.com/) who makes carbon underbody aerodynamics for the g35 and the evo.

turns out that he uses a foam core for the primary structural support in the splitters and the diffusers.
we talked about using a honeycomb matrix as a core and he said he had tried that but the resin needed to bond the composits to the matrix weakened under high heat, so he changed to the flexible foam core which can use traditional resin to bond the carbon / kevlar to the foam core.

now the foam is a high performance core used in aircraft fabrication called Divinycell and i found some here http://www.fiberglasssupply.com/Product_Catalog/Core_Materials/core_materials.html

i also found a good suplier of carbon / kevlar weave fabric for this he sells it @ $34 per yard (50" wide)
so if your doing this at home this would work out to about $120 per piece + core material, resin and vacuum bagging material.

good guide on vacuum bagging with a core http://www.fiberglasssupply.com/pdf/core/AdvBagTk.pdf

in talking to him about center underbody sections he confirmed that there is definatly some heat control mechanism needed with our center exhaust (same as the evo essentially)
some went so far as to have a side exiting exhaust and not have to deal with it at all, others kept the whole area open and brought the underbody tray right up to the edge of the piping.
he did recomend the use of NACA ducts just behind the radiator to draw out the hot air from the engine compartment.
however, if we went with a functionly vented hood we could use the hood to draw the hot air from the radiator and increase the cooling there, then we could push the NACA ducts further back to help cool the engine itself.

also, as far as a center section i have noticed that some time attack competitors are using sheet aluminium as most were concerned with cracking an expensive sheet of carbon on the first berm they went over or an "off road excursion", turns out that even some GT competitors are using coragated aluminium which has wonderful strength to weight ratio plus aluminium is a tad easier to modify and work with.

so my first mock ups will be out of 1/2 inch birch so i can get the fitment good and finalise the mounting points on the frame. the front is still planningto be a little bit adjustable and the middle and rear will be fixed.

i still have to go through the rule books to see what the limits are on front splitter extension lengths but i think the max i will try will be 150mm.

hopefully the next update will have pictures :thumbsup

go foggy!

Can't wait to see results!