NOHOME wrote:
The reason I ask is because there was a local aircraft manufacturer that made composite small aircraft. (Diamond Aircraft). I was reading somewhere that the air-frames had a total lifespan. This was not not a Cesna that could be torn down and rebuilt from the frame up but rather a scrap the thing after a certain time.
Similarly, a Ferrari GTO can be rebuilt any number of times by a wino with a hammer. Doubt that a 40 year old C4 will be rebuildable in any way shape or form.
I think that has more to do with the CF being flexed through use than simply aging...like I said it won't degrade on its own in any way.
It's an interesting question though, we have no examples to go on to see what structural problems CF-framed cars can suffer with regular use. The only 30+yo CF vehicles are pampered race cars or supercars that are used as showpieces or maybe see a once-a-year run up Goodwood at the most.
Few production vehicles have CF structural members, though. The Alfa 4C and Veyron have CF chassis sections, and IIRC the Mclaren F1 is a 100% CF monocoque. McLaren's newer cars have aluminum "rails" that the rest of the CF unibody is built around.
We have CF race boats still running that are 15 years old. No part of their life is easy, ever.
Am I the only one that is indifferent that the car is going away. Something else I was thinking is that by then the market will probably be saturated in terms of potential sales so it will be time to move on to the next Alfa creation.
What is the 8c scheduled production run?
In reply to dean1484:
2007-2010 for coupe and roadster
So the 4c is actually getting a longer run. Interesting.
dean1484 wrote:
Am I the only one that is indifferent that the car is going away.
Nope. It's not a bad car but it's not something I'd buy if I had the money...and I sure don't!
GameboyRMH wrote:
NOHOME wrote:
The reason I ask is because there was a local aircraft manufacturer that made composite small aircraft. (Diamond Aircraft). I was reading somewhere that the air-frames had a total lifespan. This was not not a Cesna that could be torn down and rebuilt from the frame up but rather a scrap the thing after a certain time.
Similarly, a Ferrari GTO can be rebuilt any number of times by a wino with a hammer. Doubt that a 40 year old C4 will be rebuildable in any way shape or form.
I think that has more to do with the CF being flexed through use than simply aging...like I said it won't degrade on its own in any way.
It's an interesting question though, we have no examples to go on to see what structural problems CF-framed cars can suffer with regular use. The only 30+yo CF vehicles are pampered race cars or supercars that are used as showpieces or maybe see a once-a-year run up Goodwood at the most.
Few production vehicles have CF structural members, though. The Alfa 4C and Veyron have CF chassis sections, and IIRC the Mclaren F1 is a 100% CF monocoque. McLaren's newer cars have aluminum "rails" that the rest of the CF unibody is built around.
Can't you say the same things about aluminum chassis and tubs? They have a lifespan as well, and require rebuilding after a certain point. It's possible to engineer the tub so that this point is a long way past the expected lifespan of a street car, but old race cars can and do require complete rebuilds. The only difference is that the average joe understands sheet metal and rivets but not layup and autoclaves, but average joes aren't the ones rebuilding these cars.
Keith Tanner wrote:
Can't you say the same things about aluminum chassis and tubs? They have a lifespan as well, and require rebuilding after a certain point. It's possible to engineer the tub so that this point is a long way past the expected lifespan of a street car, but old race cars can and do require complete rebuilds. The only difference is that the average joe understands sheet metal and rivets but not layup and autoclaves, but average joes aren't the ones rebuilding these cars.
True. And as we all know, even steel unibodies get floppy with age and need to have a cage put in to stiffen them up.
There are lots of early carbon tubbed F1 and Group C cars still racing in historics with 30 year old tubs. They are standing up better than honeycomb or folded aluminum and riveted panel cars. Those very much have a life and need to have the tubs rebuilt. So far no issues with carbon tubs. the one incident everyone points at is the Ferrari F1 car that split in two right ahead of the cockpit leaving the drivers feet exposed at the Monterey historics a few years ago. But that turned out to have been a tub that had been crashed, cut off at that point and a new nose being grafted on. It split perfectly at the join line, so yes, you will probably not be able to rebuild crashed or damaged tubs as you can with steel, or even aluminum chassis like the Elise or various Jags, BMS's or Audis.
The difference between steel and aluminum is fatigue. There's a level of cyclic stress that steel will withstand forever, but aluminum will always fatigue eventually. Steel unibodies getting floppy are probably not a material failure but a fastening one.
Looks like carbon is closer to steel in this regard - see how the curve with steel flattens out while aluminum continues to fall. Carbon doesn't go completely flat, but it does level out. Taken from a boat website, I am not advocating the use of wood epoxy laminate in road cars 
Keith Tanner wrote:
The difference between steel and aluminum is fatigue. There's a level of cyclic stress that steel will withstand forever, but aluminum will always fatigue eventually. Steel unibodies getting floppy are probably not a material failure but a fastening one.
Looks like carbon is closer to steel in this regard - see how the curve with steel flattens out while aluminum continues to fall. Carbon doesn't go completely flat, but it does level out. Taken from a boat website, I am not advocating the use of wood epoxy laminate in road cars
From what I've seen with historic cars, it's not the fatigue that's the issue, its the joints. Rivet holes becoming elongated and thus loose with folded tubs and the 70's/80's technology glue in the honeycomb tubs that are degrading. The one time aluminium fatigue seems to be an issue is for the nuts who built aluminium spaces frames (Porsche you nut jobs you) or even worse aluminium roll cages (Audi, Lancia, I'm looking at you guys and your group B rally cars) I can't believe they really did that back in the 70's and 80's, but they did.
Keith Tanner wrote:
Taken from a boat website, I am not advocating the use of wood epoxy laminate in road cars
Nobody told that to Morgan 
NOHOME
PowerDork
7/26/16 12:35 p.m.
GameboyRMH wrote:
Keith Tanner wrote:
Taken from a boat website, I am not advocating the use of wood epoxy laminate in road cars
Nobody told that to Morgan
Don't tell the Mini-Marcos guys!
D2W
Reader
7/26/16 12:47 p.m.
For the money there are many cars that are better in every way. I looks nice, but truly has a kit car feel to it. I sat in one at the dealer. Wires were hanging out under the dash.
If it would have been 40K it may have been more popular.
Psst. The Mini marcos was a fiberglass monocoque. It was the GT cars that were wood.
