Carbon Fiber

[Pacman]

How do the hoods, doors and other body panels hold up in accidents? Do they shatter into peices, bend, or what?

[ckyfish]

Originally posted by Pacman
shatter into peices

or just crack really badly

[andrave]

depends on how they are made. You can pretty much bet they won't be usable but a lot of them wil just bend. CF is pretty flexible if its molded that way, of course if you use lots of chop mat under a CF skin like most of those guys do, and they resin the hell out of the top layer to get it shiny, its just gonna crack.

EDIT: CKY fish: my brother was told that a mustang with slicks on the back, a GT40 cyl head, and a ratchet shifter was far too powerful for a young man like him to test drive (he was 21 and the cash on hand to buy it) so he walked off the lot.
My friend and I were out test driving an acura GSR and I hit VTEC and the salesman covered my eyes (WTF) and told me not to do that cause this car was far too powerful for me to handle.

[Pacman]

If they are made well, would you say that they are better than the regular sheetmetal in a fender-bender? And, if they do get cracked, can you fix it like a fiberglass bumper?

[Red]

If he would have coverd my eyes while I was driving... I would have kicked his lilly ass hard!

When I test drove a 300zxtt I told the guy... "I'm guna drive it as if I owned it"

that was fun... but at 18 the ins was to high.

[Pacman]

And the thread gets hi-jacked :axe: ...........

Why would the saleman not want to sell the car? Isn't that how they make there money? Stupid people if you ask me.

[ckyfish]

Originally posted by andrave


EDIT: CKY fish: my brother was told that a mustang with slicks on the back, a GT40 cyl head, and a ratchet shifter was far too powerful for a young man like him to test drive (he was 21 and the cash on hand to buy it) so he walked off the lot.
My friend and I were out test driving an acura GSR and I hit VTEC and the salesman covered my eyes (WTF) and told me not to do that cause this car was far too powerful for me to handle.

haha, no its was my parents decision not mine, plus the 240 is much more easily kept, ive heard really bad stories about the mkiii with what should be general matinence turning into nightmares

[Fastback180]

Originally posted by Pacman
If they are made well, would you say that they are better than the regular sheetmetal in a fender-bender? And, if they do get cracked, can you fix it like a fiberglass bumper?

Yes.

[zenkiDori]

you can fix CF but it won't look perty anymore so if you want that CF look, just buy a new whatever when it breaks. or get it painted.

it all depends on how it's made, and what fibers/weave/matrix is used. fiberimages has some videos of them abusing thier hoods and they stand up really good, they even have pics of a totaled integra, the CF hood is the only thing intact, just a few scratches.

on the other hand, i have heard some CF hoods are dangerous in front impacts because they don't crinkle like a stock hood, they just fly right thru the windshield and at/thru whoever is in the front seat.

carbon fiber is very stout if you get the right part. it will be more durable than the metal OEM parts are made of a lighter, but if you get a cheap part, like from VIS or something, they break with just minor wear over time. i have seen those hoods crack, chip, etc. just because they are like a year old.

if you really want heavy duty, carbon/kevlar is the way to go.

[andrave]

the problem is that people perceive its strength as quality...
a thin carbon fiber hood, ideally, would be flexible, crumple under impact normally, and would provide plenty of structure. And most of all it would be lightweight.
Look at the CF hoods that people use on the street... a single layer of CF with 1/2" or more of chopped FG matt on the back???
come on, those things weigh like 40 lbs. Whats the point besides aesthics?
look at what happens with a race car when the CF hood gets air under it, they are so thin and flexible they just bend back.

[Tricky1980]

i had to replace my hood once, got a vis cf hood, then rear ended a car and it put al ittle crack across above teh headlight... it matches up good but its cracked so you could fix it but its almost cheaper to buy a new one then to patch and paint. The rest of the front end was F&#^*!, but the hood just got a little crack in it.. and the hood pins held it down YAY!!! haha
JaY

[Pacman]

I've seen the videos running over the hoods and they just pop back to the normal shape. The pic is new to me, that car got f***** up!!! Carbon/kevlar hoods? That must be real stout items and cost a pretty penny.

[zenkiDori]

carbon/kevlar is very strong and expensive. real neat stuff tho. i'd like to have carbon/kevlar doors and trunk lid.

i talked to a kid at my school who is way into the VW scene, he knows some guys that build real fast VWs, they made thier own CF doors. that seems like quite a project to me, i've been researching CF and fiberglass for a while now, but i'm still very much in the dark as how you would do that.

[andrave]

surpisngly easy...
take off the stock part, coat it in release wax, make a fiberglass mold, then lay CF in the mold and wet it up.

little more to it than that, but in a nutshell...

ps: if you are painting it fiberglass is way cheaper and strength won't suffer too much.

[Pacman]

zenkiDori, I think they make doors for the S13 but I'm not sure about the S14.

[zenkiDori]

indeed, but CF is lighter, haha, but i wouldn't have the money for it anyway.

what i meant was that the whole picking the right matrix, curing, getting the mold to release right etc.

you'd also have to disassemble the door in order to make all sides, and i think that might let the outside flex a bit when making the mold, resulting in a part that doesn't fit.

but i dunno, only thing i have made from fiberglass is a square.

[Pacman]

zenkiDori, try asking HPI for S14 doors or fiber images.
http://www.hpi.co.jp/eng-home.html

[andrave]

FG is strong enough that it will stand on its own so you really only need two sides of the mold, and they would bond together to be pretty f'in strong.
BUT they would not have the crash protection of a steel bar no matter what you did to them, so a roll cage with door bars would be required.

[zenkiDori]

Originally posted by Pacman
zenkiDori, I think they make doors for the S13 but I'm not sure about the S14.
i would not want to buy them. i'd like to make them someday. if a good CF hood runs about $800, i'd hate to see what doors were going for. but i'll look into those companies to see if i can gather how they made them.

yeah, roll cage would be a necessity.

[240Dave]

If the skin of the door was CF but you still had the metal structure underneath it should be just as strong, no need for cage. But if it's just a CF skin with no structure, then you'd definitely want a cage with damn good door bars :eek:

I've seen all CF porshe skins with a full cage to provide all the protection...someone should make one for a 240 :)

[zenkiDori]

hmm, that's interesting, may be cheaper as well. i was thinkinf of splitting the door up and making CF parts of the original steel frame, so it'll be just like the steel frame, but CF. if done right i think that would be pretty strong.

[andrave]

it won't have have the crash protection of the original steel door frame, so its a waste of time. If you are running a cage you don't need the structural support of the inside frame so there is no point in molding it. If you aren't running a cage you can't remove the structual elements anyway.
period.

[Pacman]

I found this site forum searching.
http://carbon-creations.com/index.asp
They may make or have some things that you guys want for your cars.

[zenkiDori]

my point in making the inside frame would be that you could use the interior pieces, window roller, door latch/lock etc. i think if made properly it could withstand a heafty impact, maybe carbon/kevlar. if entire cars can be made of CF and still withstand a crash at high speed i'm sure a door could be made to be as strong or stronger than the factory door.

[andrave]

"entire cars" are NOT made of carbon fiber. They are TUBE FRAME and made with a lightweight, thin, and flexible carbon fiber skin.
Cars that are made using CF monocoques are made very differently than body panels.
If you want CF doors and want to retain factory crash proection, window cranks, etc (whats the point, anyway) just get some skins made of CF or wrap the steel skins in CF if all you care about is the look.
IF you made CF doors you are going to need door bars. Period. There is no race car with CF doors that doesn't have some kind of side impact protection.

[zenkiDori]

i've actually seen quite a few cars with CF doors and no door bars. mostly VWs, where i got the idea. i don't want the look at all, i'd paint over it. i just want the lightness. with CF sandwich techniques and the right material you could make it strong enough. i have seen it done, i just don't know how to do it myself just yet.

off the top of my head as a widely known example the vertex soarer has dry carbon doors and i do not remember seeing any door bars. in either case, they still have electric windows and locks and interior panels with the lightweight doors.

[andrave]

exotics usually use a tub construction where you have to step over the side rails to get into them. Thats how they get away with such lightweight doors, because the tub still protects the user because it shields the sides.
Anyway I can only preach safety if someone cares about it, if all you care about is lightness why even run doors.. hell take the seat belts out too.