Differences in Carbon Fibre

Most people buy these components for the bling factor so weight is not an issue and fibreglass inners give a more cost effective option and ridgidity.

I doubt many owners are trying to reduce the weight of their car, the reduction is so minimal as to have no effect.

Yours sounds like a different case where you need a bespoke product which is functional.

Its actually not that difficult to make non structural carbon fibre components, small batch quantities of materials are readily available and the old wet lay technique will make the item slightly heavier than infusion or pressure treated but still provides a nice practical product.

Give it a try, I made a few small items using woven fibreglass first and soon got the hang of it. Good fun actually and very rewarding when you pop a mould and trim a nice new component

 

You might want to contact the following Carbon Fiber producers who are also sponsors here on FerrariChat:

http://www.carbonio.com/

http://www.macarbon.com/

http://www.ferraricarbon.com/


Mike

 

There's this:

Carbonio Performance - Ferrari 430 Airbox

and this:

http://www.macarbon.com/index.php?page=shop.product_details&flypage=flypage-ask.tpl&product_id=69&category_id=168&option=com_virtuemart&Itemid=50&lang=en

Mike

 

Yeah a fibre glass frame with a layer of carbon fibre isn't a substitute for the real thing.

What happens you get into an accident with a carbon fibre panel? If you get a dent in it, does the whole panel have to be replaced?

 

Carbon doesn't dent. It breaks.

There are several companies out there that can actually repair carbon.


I think with no8080 is getting at, is that he is (rightly) pissed off with companies charging real carbon prices for pieces that are just fibreglass with a layer of carbon on it. Won't name any names , but have seen evidence of this myself too. Several well known companies that people here use.

Just about every single non structural part by Ferrari is made in the same way, and you get charged through the nose, as if it is a real, proper part. Ordering every single ''carbon'' option actually adds weight, funnily enough. Does look cool, though.

I'm quite sure if you order a Ferrari without the carbon bits, take them off when the car is delivered and send it to someone that knows what they're doing, they can make identical pieces but in real carbon, for the same price Ferrari would've charged as options.

No need for autoclave either.

 

on a 3500 lbs car what is the point of non structuraal cosmetic Cf pices. What are you going to save by going full carbon a few lbs at most. CF is a fashion fad, like in many cases owning a ferrari. People like the look of CF.

Now if you doa Cf tub, or real CF wheels or some big CF bosdyparts then yes there is a big potential weight or operformance advantage.
But if its cosmetic pieces, then people like the weave to look perfect because its cosmetic, and that si what these pieces are.

Its similar with helmets, CF is the new gotta have it. But most weigth ina good helmet comes from the liner and soft amteriral, not the shell.
CF also splinters in a crash. If you compare the weight of a very good non Cf Arai helmet to say another brands Cf helment you may find the Arai is lighter. Even if you soend $3500 on a Arai Cfhelment the weigth savings are negligable.

So whey then go to all the trouble of real CF airboxes or Cf splitters(as opposed to plastic) these pices dont have a whole lot of structiral strenth and real Cf weight savings are minimalif if at all, looks cool though, in whci case you can just have CF coated plastic..

 

lack of weight is the first thing that one notices when picking up a true CF part...

a full CF structure will not have thickness or bulk of the same structure (part) made from other material...

CF parts are about getting greater strength at lower weight

resins are used to make/bond the CF in parts, unlike glass fiber parts CF does need as much resin to create a good bond, glass fiber is a high bulk material that requires a lot of resin to saturate the glass fibers to create a solid structure... the weight is in the amount of the resin used to create a bond, less material leads to less weigth

CF parts are very susceptible to UV, in the same way wood finishes break down when exposed to UV... CF itself is not affected by UV but the resins are, left untreated a part can become weakened by UV... UV filters are added to the resins and clear finishes which will extend the life of CF parts... best CF life extender is to use paint ( opaque finish ), if one does not want to have the clear coat break down and peel...

as has been mentioned, parts can be wrapped in CF... which is a way to get the look at little cost... one needs to be careful as the difference in cost to make a full CF part is large... one can pay a lot for a bogus part

 

Comparison of steel drive shaft vs CF: [ame=http://www.youtube.com/watch?v=hjErH4_1fks]Steel Shaft Vs Carbon Fiber Shaft - YouTube[/ame]

 

Disagree there. I've felt the difference between 2 identical motocross helmets, from the same company, one with CF shell and one with normal shell, and the weight difference is significant. Both where new in box, same FIM approval stickers, build in the same year etc.

I'd much rather have a CF helmet than a non CF. Lower weight can be significant in reduction of head injury where lots of G forces are involved.

I can see where you're getting at with it not mattering about Ferrari (and others) using their way of carbon for 99.5% of the people. I just hate the fact that you're being charged for proper, pre-preg carbon and all you're getting is glorified plastic, with none of the weight gain.

 

I have had some real CF parts and some fake-real CF parts.

Real Carbon Fiber uses a high strength epoxy to bond real carfon fiber weave into a permanent structural part. These parts are vacuum bagged and cooked in an autoclave to cure the expoxy. Lacquer thinner will not harm the surface or finish of these parts.

Fake-real Carbon Fiber uses polyester resin to bond real carbon fiber weave into a UV sensitive non-structural part. Lacquer thinner will eat the polyester.

 

PM sent.

Agreed; lots of "fake" cf out there. You get the weight and structural properties of fiberglass, but at the cost of carbon.

 

I am comparing the weight of an Arai kevelar to other companies CF helmets and the Arai is lighter or the same..

 

I think you may be mixing and matching some terminology.

Carbon fiber is the basic fiber we're talking about. It's much like (but certainly not identical to) the fine cotton thread used to make the clothing you're wearing.

This fiber can be sold as long unidirectional fibers either as something resembling a big wad of loose yarn or glued and/or stitched together in a non-woven, unidirectional ribbon.

Or, just like any other fiber, it can be woven into a cloth. in which case it's called (no surprise) carbon fiber cloth. Various weaves are available depending on the end use and various combinations of woven cloth and unidirectional fibers can be stitched into layers for particular uses. Carbon fibers, glass fibers, and Kevlar fibers can all be combined in various ways and various combinations.

When any of these carbon materials are impregnated with some sort of resin, it forms a composite matrix. Most high tech products are made from "pre-preg", which is made from carbon fibers, either a cloth or a unidirectional product, impregnated with a resin and a hardener (nearly always epoxy of some sort) at the factory. It has a lot of fiber and very little epoxy, and that is very desirable from a strength to weight ratio standpoint and impossible to achieve with a traditional wet lay-up process. This stuff will eventually cure by itself and to delay this curing process, it is often refrigerated before use.

After this pre-preg material is cut to shape and put together in a mold, the component is nearly always put in a vacuum bag (to squeeze everything together) and cured in an autoclave at elevated temperatures. This is how F-1 bodies are made. The result is a carbon fiber composite; expensive with a high strength-to-weight ratio.

Or, a dry carbon fiber cloth or unidirectional material can be wet-out with a resin and hardener mixture and then cured. It could be made in a female mold or over a male form. This process could include a vacuum bag or not and it may or may not include curing at elevated temperatures inside or outside an autoclave. Depending on the process, the ratio of fiber to resin will vary, perhaps considerably.

Because of the extra cost of carbon fiber vs fiberglass, epoxy is nearly always used as the resin. But there is no reason that polyester couldn't be used.

Furthermore, anything I've said so far about carbon fiber applies to fiberglass and Kevlar too. Carbon fiber, fiberglass (there are many types) and Kevlar can be handled in a similar way but, of course, they have different properties some of which are attributable to the fiber, some to the binding resin, and some to the method of construction. In addition, many of these reinforcing fibers can be especially treated to be more compatible with whatever resin will be used for the composite part.

As for UV resistance, typically UV is a more serious problem with epoxy components often because they're more likely to be used where structural integrity is very important. In fact, epoxy parts are normally quite UV sensitive. The basic epoxy can be blended with additives to reduce the UV sensitivity and/or the finished product can be covered with a protective coating, usually paint. But polyester and vinyl-ester resins are not immune to UV issues either.

Lacquer thinner may or may not harm any of these composite structures, but it is certainly not correct to say that it won't harm epoxy. For example, high performance helmet manufacturers print very strong warnings against letting any solvents of this type contact their epoxy based helmet shell. Furthermore, the typical high gloss surface of a finished epoxy part might be due to an extra heavy coat of resin applied to the inside of the mold and allowed to partially cure before the cloth is put in. This thick layer of resin can then be sanded and buffed to a high gloss without showing the "print through" of the cloth weave. Or, more likely, the part might be coated with some sort of clear paint-like finish after being removed from the mold and this clear finish can be then sanded and buffed to a high gloss. In this instance, the surface is almost certainly not epoxy, so it may or may not be sensitive to various solvents or UV light. Furthermore, for styling purposes the cloth "print through" may actually be desirable. For example, I have a carbon fiber Ferrari key ring made to show the texture of the carbon fiber cloth.

Finally, when it comes to things like air boxes, what everyone is really after is that "cool look". The best pre-preg carbon fiber part made in an autoclave will be fractionally lighter (but much more expensive) than a good part made from high performance fiberglass/epoxy and a really bad version made from chopped fiberglass mat and polyester will be only a little bit worse. A part like an air box, which much have a certain rigidity to do it's job correctly and a certain ability to hold a fastening latch may have a very light and thin carbon fiber shell, but the edges and latch areas must be more robust to do a proper job. In fact, including a bit of less expensive fiberglass in the matrix to provide the required bulk and thickness in certain areas is not a bad idea and is certainly not fraudulent. Remember, we're not talking F-1 here and ordering a single burger for lunch rather than a double with cheese will more than make up for any weight difference.

And lastly, some of us think all this fascination with carbon fiber decorative parts is just plain silly. The idea of carbon fiber door handles for my 360 Modena strikes me as about as worthwhile as making some custom air boxes showing hundred Euro notes in the exposed laminate. But that's just me. You are the boss of your own after market components.

 

Mozella Thanks for that comprehensive description.

As I have thought for a while a lot of CF is decorative, a cool look. One only needs look at a CF sill option on a Macklaren or Porche to realise you are buying non structiral plastic with some matt on it.

A lot of so called Cf tubs like those int Mclaren aventador, 4c and BMW I series are probably not vacum bagged prepreg as a F1 car, although may arguably be lighter than aluminum and stiffer, in fact ferrari disagrees here on the weigth and stiffness vs aluminum.

If yoiu areally want to see a proper light CF tub on a road car look at a Maccca F1.

The different production methods and what is invoilved partialy explain why an Arai CF helemt is $3500 and other $1000.

Sufffice it to say CF is the fashion material on high performace cars, just as the monochrome look was int he 80's. Maybe bpeople will get tired of the Cf look too.

A recent look at the dodge viper TA showed CF look between the taillights and on the rear wing. To me it cheapened the look of the car, far better to have these parts body color or just matt plastic.

I agree all these non structural small so called CF pieces, even if they were real vacumes bagged CF might save at best a few lbs. But they sure are a way for manufacturers to charge throusands extra for essentialy different plastic trim, which I suppose is what aggravated the op, the cost for CF matt coated plastic..

These days is ee slammed 90's honda with CF bits, so possibly the look is on the wways out. Sadly we may end up with matt paint as a replacement look.

 

Excellent post Mozella.

 

Where I have carbon fiber is in my bikes. Trek Madone is what Lance Armstrong (leave him alone) rode to victory. Scott makes my mountain bike that is light as a feather. Have an old GT in thermoplastic alien stuff. Bikes really are made of some cool CF stuff too.

 

so your point is that real carbon fiber 100 percent is not made by these f chatters..All in all the quality and look is good, and the weight is lighter than original ferrari parts plus they look great,,IMHO

I upgraded for the look and to me the look and quality updates the cars look

 

This is not entirely correct.

This is probably the biggest myth of CF: That it's always rigid. I have a friend who makes recurve bows out of CF, and you can bend the tips together without breaking them (It takes about 200 pounds to do it!).

Short answer: It depends on the formulation of the resin that you put the woven carbon matrix into, but the tightness of the weave is also a factor.

Cheers,

Geo

 

Bas Jaski didn't say a CF/resin matrix doesn't undergo elastic deformation. He said, in effect, that it doesn't experience plastic deformation like aluminum. For example, if your friend made bows out of aluminum like that used in Ferrari bodies, bending the tips together would result in a bow which would be permanently bent and unusable. That's because it was taken past the range of elastic deformation into plastic deformation.

CF parts typically experience elastic deformation too, like the bow you mention; i.e. the part can "spring back". But once the elastic limit is exceeded, the part is likely to fracture rather than bend. Try bending that bow into a tighter and tighter circle. At some point it will break. That's what Bas Jaski was trying to say, I think.

 

CF has a high modulus which means that it does not yield to forces trying to stretch or deform it... essentially unyielding...allowing for CF to take high loads / forces...this high modulus also makes it susceptible to excessive flex if forces exceed the limits leading to failure... CF structures should not be exposed to point loading which will lead to failure, it is important to distribute loads over an area... CF structures can also cause galvanic corrosion to metal fastenersi that are not properly isolated... CF is great when used properly, it also can be forced into failure by improper use