Still no legitimate response to why my idea sucks.

 

Do some research, come back and post your findings.

Those of us who know already know, "be productive" and learn something today.

 

Then what is the forum for?

I'm ok with doing research, and I'm ok with learning. I'm ok with being wrong if I can then learn something from it.

What I can't stand is being told I'm wrong by someone who won't then teach me something.

 

Theres a difference between teaching, and spoon feeding.

Your car isnt sitting in the driveway right now with a few wiring problems stopping it from driving and you asking for help, if you were you'd be getting answers.

You posted up an off the wall idea that has little feasability, and dont want to do any research as to why, if you wont help yourself, why would I help you ?

 

You guys crack me up. backgammon7's ideas are probably the best on this entire thread. He came up with really productive ideas that would actually help (unsprung weight) and are completely feasible for carbon and are easy to do. Making a carbon tube really wouldn't be that hard compared to rest of the ideas here. Basically you are talking about a much simpler version of a carbon bicycle frame. You can even buy premade tubes. The hardest part would be figuring out how to attached threaded ends. But we are not the first people to think about doing this.

 

Which part about a bicycle frame requires caps for bearings to bolt in, which much be very aligned with another bearing location 90* to that, along with two other bearing locations inline with the first two, and is subject to 300-600 ft lbs, connected through a 2.5 - 3:1 gear reduction, with a 3-4:1 reduction inside it ?

Even the tubes alone, you've got a lot more than just the axles going through on them, the majority of the rear suspension mounts to them, carbon works good for things that have a particular force on them, but often not so good in multiple directions, the bending of the axle tube due to the lca mounts, and spring perches, after you came up with a way to affix them, would not turn out well.

Carbon driveshaft holds up long ways twisting, yet smack it from the side like the loading of the rear suspension mounts, and its done into dust quickly.

Also, a driveshaft just brooms and cleans the underside of the chassis when it goes if its carbon, whats going to happen to a car when an entire rear axle tube disappears into dust and you are missing your entire rear suspension and wheels, quickly ?

 

Never seen axle tubes with bearing caps or bearings in them. Maybe you missed the part where he said AXLE TUBES not the housing, not the ends.

Simple torque and bending tubes (axle tubes) and tension/compression tubes (lca, panhard) are quite easy to design. The challenge comes in manufacturing the tubes to a specific standard. For this type of home build each tube would have to be proof loaded before I would use it. And you would really want to test the failure load at least once as well. Really these are the reasons you don't see much aftermarket carbon parts. Except for silly decorative parts.

 

So, uh, just a wild thought here, but what supports the axle at the end, you know, by the wheel ?


Ok, cool, so when you've come up with an idea of what it would take for this guy who can lay up some carbon decorative interior parts will need to go ahead and make this guys shoot for the moon axle tubes, the actual materials required to achieve the strength needed, the qc tolerances and standards, etc, as well as an actual selling price for such an item, feel free to let me know how great an idea it was for someone who is looking to make non structural parts.

Dont forget the part about where if it gets hit or damaged on the road, you're going to lose your entire rear suspension and wheels.

To sum it up, i'd love a carbon fiber case for my transmission, gundrilled cr-mo mainshaft, unobtanium gears, as well as some titanium shocks, forged aluminum wheel hubs, etc, but the reality is the cost of each far exceeds how great an "idea" it is.

 

I see you have since edited your response, so I will address those concerns.

The suspension points would indeed be the hardest part. Clearly I would suggest making carbon lcas and panhard bar first. Those are a lot easier. But you have only brought up the axles tubes and ignored the rest of his suggestions.

It is a common misconception that carbon fiber products turn to dust when they fail. That is simply not true. They yield and break just like any other engineering material. Actually its the matrix material that yields first then the next mode is the fiber breakage. But as a whole it acts like other materials just with different slopes and magnitudes.

Here is a picture of a composite structure that has broken during testing. You can see it did not turn to dust.



Regarding the combined loading scenario. The carbon can be laid up any way you want. The beauty of the material is that its strength can be tailored. You can lay up carbon to be basically isotropic, just like metals. So that really isn't the issue.

You bring up what to do when the carbon fails. I will reply first with a question of my own. What do you do when their metal counterparts fails? The answer is quite simply, that you design them not to fail. For structure that has no alternate load path (like most automotive components) you design a huge safety factor into them. That is considering environmental effects, flaws in the material, flaws in manufacturing (layup, fiber wetting), unusual loads (road debris). And finally the failure mode need to be obvious in regular use. A broken LCA or Panhard will not likely send you flying off the road. On the other hand, if you have a crack in your axles tubes, you should notice fluid leakage before catastrophe. A fracture toughness study.

Nowhere do I claim its easy or desirable. But to me at least this is way more interesting to think about than CF headliners. If you are interested in having a civil discussion, I would be happy to continue. If you want to resort to childishness, that is fine too, but then I will stop as its not my style.

 

The axle end clearly would be AL. The bearing is pressed into the axle end, not the tube. It would not be reasonable to build a CF axle end. We can all agree on that.

You are quite right, its not feasible for a shop like the OP's to build structural parts. But I think its fun to think/talk about. Maybe we need another thread to talk about this kind of stuff, so we don't clog up the OP's thread. Personally I think the best applications of CF on a third gen are, in order:

Hood (weight reduction yet good stiffness)
Driveshaft (better strength/weight and better harmonics than AL, and products are already commercially available)

And a few other (intake, doors, lca's, panhard, STB)

 

First off since you want to jump at the board showing you that I edited my post, indeed I did, I added the last line about the wish list, good job bringing up nothing.

Can you please show me the structural strength of "dust" compared to the leftover fibers of a failed carbon part, and how well each will hold the axle under the car ? I have a feeling they will do the job equally.

You want to act like you're hopping on a high horse about the arguement, yet you are the source of it, you've tried to act like it was a feasable idea, when it is not, and was clearly beyond the reach of what the OP was looking for.

To your lca and panhard comment, sure a panhard wouldnt be very dangerous, however a broken LCA could very well be an extremely dangerous situation.

You continue to preach your "civil" vs "childish" discussion, i'll stick with "realistic" instead of "childish hopes" and posting for the sake of arguement which is all you were doing trying to say that his ideas were good, when within the content of the post they were terrible.

 

No, you added the last 3 paragraphs. See my previous quote for what you originally posted. Anyway I don't see the point in arguing, you edited your post, and that is fine.

You changed the subject, I was merely pointing out that it doesn't turn to dust. But to answer your question, clearly there is little strength left. But on the other side of the argument a similar failure on a metal structure would have little strength left. So maybe I am missing your point?

He is a very similar example of a bend test but with AL this time. Go to 2:00 for the good stuff.

Agreed, it is beyond the scope. That however does NOT make it a stupid idea like you have made it sound. You made it sounds like a disaster waiting to happen, clearly. Which if designed properly its not.

I disagreee. The purpose of the LCA's is to keep the diff square with the car. If it fails, the other will pick up the slack. IMO, a panhard failure is more dangerous than a single LCA failure.

I couldn't disagree more, but that is ok. I actually don't really care what you think. I'm more concerned that people will come on here and take your word as the truth and have an incorrect opinion of the physics of composite materials. I suggest to all the members, to take a class in the mechanics of composite materials if they are interested in learning more. I can also recommend the following text book:

 

If an axle tube was struck with an object while driving a metal tube would be dented, or at worst likely bent, comparable force to a carbon tube would shatter it.

The point, hit metal, it doesnt go poof.


Yes, it would be a disaster, whether you can comprehend it or not, if the lca is gone and the differential moves the tire is likely to quickly make contact with the body, this isnt likely to end well, and is not such a moot point as you seem to insist.

A panhard failure just makes the car a little unstable.


So in conclusion, more stuff about how with an unlimited pocket, and more money than sense, you can have carbon axle tubes. And still nothing realistic that the OP could make, and was asking for input on.

 

I will start a new topic later this evening. Like you, I feel like we are getting off topic, but I do think its a worthwhile conversation. I don't want to clog up this thread further.

 

Bumper cover inserts for the Formula - need to have provision to securely hold the Laser diode jammer heads (all 4 corners)!!!

 

my vote for post of the year

 

Is the OP still here? Is he making anything?

I would love a CF Chinspoiler, heck full GFX, rear spoiler ( esp. a tall hawks style) Trunk lid and hood.
And a stock IROC style hood.

 

In my opinion it's not a bad thing to bring up ideas that seem difficult or nearly possible. That's how innovation happens. The argument that carbon fiber turns to dust or goes poof is silly because from my understanding it doesn't unless it is impacted with something so greatly, but how often does a tree trunk or gigantic rock impact our axle tubes??

 

It wouldnt need to be a tree, sharp focused impacts are very likely and would damage carbon, where a steel tube just shrugs it off.

 

That is simply not true. Are you aware of all the aircraft structures that use carbon fiber composites? Aircraft structures are sized to meet MANY high impact scenarios including but not limited to:

8lb bird strike at cruising speed (500+ mph)
3lb hail at 110 mph
Shredded tire at landing speed (200+ mph)

It all depends on how you design and build it. You are making incredible generalizations.

 

Feel free again to show the designed axle tube and what it would take for it to withstand such things.

 

Feel free to show me where airplanes are falling out of the sky due to impact with composite structures.

While I have provided many examples of what I am talking about, I have not seen a single example of what you are saying. And I am still waiting.

To design an axle tube would take some serious effort. Mostly around figuring out the worst case design loads. I don't have the kind of time to go through weeks of effort just to prove something. If anyone is seriously interested in building something out of composite material, let me know, I'm happy to help.

John

 

I bet somewhere is a race car already using carbon fiber axle tubes.


But does any of this matter, it does not look like this carbon fiber builder is interested in building stuff for third gens either.

 

http://www.bactechnologies.com/torque_tubes.htm

http://www.bactechnologies.com/atv_axles.htm

 

You want me to illustrate it for you since you want to play examples while only having touched on the surface, fine.

http://www.faa.gov/library/manuals/a...apter%2002.pdf

Carbon fiber is generally stronger in tensile and compressive strength than fiberglass, and has much higher bending stiffness. It is also considerably lighter than fiberglass. However, it is relatively poor in impact resistance; the fibers are brittle and tend to shatter under sharp impact. This can be greatly improved with a “toughened” epoxy resin system, as used in the Boeing 787 horizontal and vertical stabilizers.


http://www.glen-l.com/weblettr/weble...materials.html

Besides being weak in impact strength, carbon fiber is weak in sheer strength and must therefore be shielded from abrasion.



There are just two examples, there are plenty more, sure BOEING may have the capability to produce a thirdgen axle tube that will hold up for a while, but again, I asked you to keep it realistic, and the REALITY is that you are reaching for thin air with suggesting anyone on this board is likely to produce a usable carbon fiber axle tube, and even if there were someone on this board working for NASA, or BOEING that could do so, there isnt likely any 10 people you could round up that could get together and buy 1 set, for the whole group.

Oh and apparently even at BOEING it isnt quite as simple as you seem to make it to be, keep in mind those shims they are referring to are metal, and from what I could find about the thickness of a post-it note, something so extremely thin to make sure that the shell isnt preloaded at all, good luck with those axle tubes.

http://www.dailymail.co.uk/news/arti...ter-shell.html

 

Those are some crazy drool-worthy parts there Our cars are heavier than the vehicle in the link but like 87350IROC mentioned it would have to be designed to handle the weight and abuse or racing/street driving which is possible, but it's highly unlikely anyone would produce something like this when for example, midwest chassis already has a rear end that is lighter than a 10 bolt rear yet stronger than a 9 inch rear, and it uses an aluminum center section which according to this link is weaker than properly built carbon fiber parts.

 

Hmmm. No one is questioning that the carbon fibers are brittle. They are. But you don't make things out of carbon fibers. You make things out of carbon fiber composite (fibers + matrix (epoxy resin)). As your link points out, the material system is toughened. That is what we are talking about. The fibers themselves aren't an engineering material.

Of course, as above nobody is talking about making the tubs from just the fibers. Its the whole material system. The matrix material shields the fibers from all kinds of environmental and in service effects.

You might be surprised at the kinds of people who play around with third gens.

Show me where I suggested that any old person could design and build such a piece? In fact, I have stated just the opposite.

 

It can be improved upon as in it is often exactly as I said, improved upon means with enough $ thrown into designing a resin that is good at impact resistance, they werent just referring to the fibers as you claim.


No I wouldnt be surprised, what would surprise me is that you would manage to find someone with the funds to do something so silly, and have them do it, rather than going for an IRS which would cost less and gain more.


Posting your contradictory statements as to the feasability of such a product, in a thread that is clearly aimed at suggestions for what the OP could make, so that it is available to the thirdgen community, yeah indeed you werent implying that.

 

While it is indeed a cool thing for the race car axle tubes, again this is an example of where things are an ok idea on a race car, but not a very good idea on a street car, race and street are two very different environments.

Race tracks dont often have things like potholes, curbs, road debris, they get caution flags waved around when one of many people watching the track carefully spot something, this doesnt happen on the street.

Things like aluminum heim joints for suspension and steering, hollow bolts, linear valved shocks, all generally great on track, not that great on the street.

Also the torque tube is a good bit different than an axle tube.

 

An IRS handles worse than a solid rear axle and weighs more (this depends on the driver and track style ofcourse). If you had carbon type parts on the solid rear axle it would be even lighter. We all know the benefits of lighter un-sprung weight especially on our cars, also installing an IRS on our cars requires LOTS of modding on the car itself whereas a solid rear axle will be more or less a bolt in design.

I agree with you about the street vs. track argument. It's quite possible that only a track-only thirdgen with a large budget could benefit from something like this, although you would never really know until it was built and tested, and maybe it would outperform more expensive exotic cars for way less money?

I watch out for potholes and curbs as it is now and I have only regular performance street parts, like any performance part it would require more attention to how you drive on the street. In fact lighter un-sprung weight in the rear would help the rear of the car be more stable and less harsh over uneven roads and potholes. Also, potholes don't jump out of the ground and attack the axle tubes either

 

Quite often on the street they dont have to jump out, remember on the street you've got plenty of other people around you with cars that bump yours around just fine, its not uncommon for someone to post up where their car was destroyed or they had to drive into, over, onto something by no choice of their own.

Also, what full on race cars currently are running solid axle, instead of IRS, because it handles better ?

 

I'm not seeing this solid axle in this race car, and i'm pretty sure its all about handling...









I wonder who forgot to order the carbon tube'd solid axle ?

 

Sigh.. Well if that unfortunate accident were to occur then I would imagine the car is totaled anyway.. If my steel rear end was bent I would replace it anyway.. Wouldn't you? By the time I'm driving over another car chances are it's far too gone. The last thing I'm thinking about is the fibers breaking apart on the rear end..

Full on race cars shouldn't be compared to thirdgens and the machine in the picture is built ground up for a certain purpose. I doubt it's meant to be street driven, probably designed for a specific track or style of driving.

No doubt that IRS is better for street because roads are not perfect. Potholes, bumps and uneven roads cause a solid rear axle to behave rather annoying but very driveable nonetheless.. An IRS will obviously be more comfortable and provide a more luxury ride and is preferred by most of the market who want that type of ride.

I don't mind driving over bumps with a SRA maybe because I'm young and can still tolerate it but mainly because I know I can rip it in the corners and because of certain upgrades it performs quite well.

But the argument of IRS vs. SRA is old and I'm sorry I argued this, we should resume conversation about carbon fiber parts and such.. Some people like to innovate, dream and yes maybe post up an idea that to some may seem ridiculous and a complete waste of time and money while others may not, that's the brilliance of an open forum where people can post opinions on things. Your opinion on the matter is clear, but I for one would pay big bucks for lighter weight parts, especially if it's unsprung weight.

 

Its a Grand-Am car to be specific, but again you said solid axle will handle better, yet thats built for all out handling.

Saying irs's only merit would be a more comfortable ride is pretty damn silly, IRS will always be a better method of suspension design than solid axle for handling.

If you want to save thousands for a carbon tube'd axle, go for it, just dont be too surprised when someone blips right past you running IRS.

 

I think this thread has clearly run it's course. At least until the op returns and offers to build some of the aformentioned carbon fiber parts.

Until then, I'll keep dreaming of a carbon fiber decked out iroc.

 

Me too, but with IRS

 

Using one example doesn't justify tons of other examples where solid axle race cars beat out IRS cars on road courses. Both are good for different reasons.

A light weight race car such as the one posted above probably has a larger amount proportionally of unsprung weight to sprung weight when compared to a street car like a thirdgen, so lighter race cars benefit more from independent rear suspension (the heavier unsprung weight would cause the car to have trouble handling properly over the slightest imperfection in the road with a SRA, so independent rear is better for this particular race car).

Another point is that an IRS has less anti-squat, so it works better on car with a greater rear weight bias, which isn't common for a typically heavy front nosed thirdgen... SRA is much better for drag racing as well which is also what most thirdgens are used for anyway.

and I will keep dreaming of a super lightweight carbon fiber rear-end LOL. It's nice to dream!

 

This is not a thread for IRS vs Solid Axle.

It was a thread about possibly building some Carbon fiber parts for us, but as I have said the OP has not been around in awhile to offer the production so the thread is dead.

 

Deck lid please.

 

I like the idea of the air cleaner housing for a tpi motor. the tube is fine in the rubber. I would think some sort of engine cover for the Tpi motors kinda like the ls motors have to clean up the engine bay alittle or maybe a nice tpi overlay that would bolt on or 2 sided tape on to the tpi for a custom look. yea the grill is a nice idea once his first order is done and he is caught up i might order one but 6 + months to get one is alittle long for someone with no patience like me I hate to order online cause it takes to long. I like the interior pieces in carbon that would be cool complete center console top from the radio bezel to the console glove box lid use the stock console lid but new carbon everything else. right now you can buy carbon overlay gauge plates so no need to make them . I like the idea of the carbon deck lid and rear spoiler, mirrors, but the rest like gfx would be to much and time consuming. emblems yea would be cool but if not done right would be to plain. one idea that was said was kinda cool but nit sure if it was the whole t-top or just the outer black bar I would do the outer bar on the t-top. the spitters are a cool idea one reason for the front splitter would be to keep your chin sspoiler from getting messed up. the side ones look good like in nuff nuff 's car the rear difusser is a good idea but wouldn't look good with out the rest of the car matching . a carbon fiber sub box would be cool but personally I don't like the idea of it filling up the whole trunk area.
Doors yes a good idea but for safty sake I will stick with steel ones. unless just for racing.

so for my car what would i do hood grille center console TPi airbox tpi overlay, t-top side bar front and side splitters mirrors deck lid and spoiler.

also on a side note I like this site alot but the petty stuff needs to stop. yes everyone is intitled to there own opinion yes they are. this site is for constructive help not flaming or degrading people for there ideas what if someone did it to the wright brothers (which they probably did ) we wouldn't have teh idea's of the airplane these are idea's just cause one person thinks it can't be done doesn't mean it can't be done. if that was the case we as a society would never move forward.

 

If you check out the grille thread, it appears mmy have gotten scammed by that guy and will never recieve their grille.

 

Well said.

 

Thank you

 

Well stated! If people are not willing to share CONSTRUCTIVELY then don't share! The point of ppl asking questions is go get them answered buy someone who knows, not to have some old grandpa start swinging a cane at them and calling them a stupid wiper snapper. I think that it's the responsibility of an older generation to give the gift of experience to a younger generation. But the biggest thing is do it without being an A$$ HOLE!

 

Good posts 87350IROC. I see you also have aviation experience in composites? Just sort of skimmed through the thread. Lots of misinformation about CFRP. Most of the parts people ask to be made out of carbon fiber are basically a waste of that material.
If you just want something to look "cool" then you are better off using one of the dyed fiberglass fabrics they sell now. In fact, fiberglass is a great material and some types of fiberglass are actually stronger than some types of carbon fiber. Strength should not be confused with stiffness however.

CF should be used for structures that are stiffness driven, and even then, they are seldom if ever used alone without other materials. This is why I am amused when people criticize some "carbon" parts if they find that there are other materials in the laminate.. as though the manufacturer was being "cheap".
If you think that you'd hate to see what a laminating schedule looks like for some aircraft panels. I mean, why would you use an aluminum honeycomb core, lay fiberglass on it, and then put carbon over that? Any ideas?

I think CF is best use in our cars as a reinforcement for structures that are stiffness driven where the primary material provides enough yield strength but not enough stiffness. In order to design a part with enough cfrp that the primary failure point would be the cfrp.. you better know what the heck you are doing, not just in the design, but in the manufacture.

In the case of an axle, it most certainly could utilize carbon as a primary material and the amount would depend how it's designed. As I said before, you'd seldom use CFRP alone and there are other materials that can address things like impact resistance (aramid for one). In order to rely on enough composites that they would be the failure point would cost a fortune. So I come back to my opinion that cf should be a reinforcement on things that you know will not fail but may be made out of base materials that are not stiff enough to avoid elastic deformation, where that material has a worse stiffness to weight ratio than CF. Of course when you reinforce something in some place you introduce a stress riser somewhere else...

...and then this doesn't even touch the world of resins and adhesives.

So in short, I can definitely see carbon fiber reinforced control arms (with a different primary material providing the ultimate strength) that are affordable. Pure CFRP suspension parts? Not anything that wouldn't require a fortune.

 

Okay, now that I'm finally back from deployment, I can get back on some of this crapola.

I will admit first off that some of the parts that I have been looking at making would be aesthetic. Honestly, there are some parts (especially those involved that may cause the operator to lose control if they fail) that I wouldn't even want to touch from a liability standpoint...and I have been dealing with composites for several years now.

As far as some of the ideas that have been brought up on here; I should be starting off on the fab soon. If people want to buy something, cool...if not that's okay too, both of my third gens will get what I want to bolt on. One of the reasons why I started thinking about swapping OEM parts for CF/Aramid is because of my desire to 'make something mine' in a custom sense (and honestly, I'm not a big fan of textured plastic).

Either way, I will post finished products once they are finished and if anyone is interested in getting something, we can go from there...

 

Keep us posted

 

Will do. As of right now, the following parts are on the to do list (parts for firebirds will have to be measured or scanned first (since I do not own one)).

Dash Pad
Center Console Lid
Door Skins (cards)
Front fenders
Shift plate
Radiator cover
Battery tray
Chin Spoiler
(potentially) a modified SS spoiler
Custom 3 pod gauge cluster (mounted under the center Hvac vents)

Realistically it'll be a little while to get back into the groove of things not to mention having to wait for the Kevlar, Carbon Fiber, honeycomb membranes and resin to be shipped. Plus the construction of the vacuum molds.

Once I get to that point and start making them, I'll post photos on here as well as a price (if someone wanted to buy something).

I'm not looking to start a composites business on here or anything, just making stuff available for other third gen owners (without raping them on the price of buying composite parts). Please keep in mind though, a lot of this stuff will be cosmetic only.

 

Man, did anything ever come of this?
I'd love a cb chin spoiler.

 

Man, did anything ever come of this?
I'd love a cb chin spoiler.