Kizashi Club

Your Kizashi Owners Club and Forum 

The Kizashi should soon show up in Australia. We look forward to seeing members from your region.
 #27484  by ~tc~
 Mon Apr 28, 2014 8:01 pm
Kuro, once again you skimmed my post ... I said if you had clear resin with the fiberglass to have the same look, you would likely have the same problem. Obviously, if you use a nice automotive paint, you won't have the problem.

Yes, CF has to have some kind of matrix to transfer the load to the fibers and hold the shape ... Just like all fiber reinforced composites, from concrete to fiberglass to carbon fiber to even more exotics. Not all matrix materials require "baking". An autoclave under vacuum is the best way to ensure the fiber is well bonded to the matrix material, and is frequently used with carbon fiber because if you're paying that much, you want the best performance possible - this technique is also used with fiberglass, but more frequently, and epoxy type matrix is used that has an exothermic curing cycle so "outside" heat is not required.
 #27486  by KuroNekko
 Mon Apr 28, 2014 9:10 pm
BxKizashiS wrote:Soooo with reading all you guys posts, carbon fiber is not worth it lol... I might as well get it wrapped or just leave it how it is

Yeah, CF is totally not worth it for this car. Maybe a track car where every pound off can make a difference. For a car like a Kizashi and comparable cars, it's not worth the high cost. Keep in mind that the Kizashi is also rapidly decreasing in value so investing in expensive mods that won't do much for performance like a CF hood or roof is ill-advised.


~tc~ wrote:Kuro, once again you skimmed my post ... I said if you had clear resin with the fiberglass to have the same look, you would likely have the same problem. Obviously, if you use a nice automotive paint, you won't have the problem.

Yes, CF has to have some kind of matrix to transfer the load to the fibers and hold the shape ... Just like all fiber reinforced composites, from concrete to fiberglass to carbon fiber to even more exotics. Not all matrix materials require "baking". An autoclave under vacuum is the best way to ensure the fiber is well bonded to the matrix material, and is frequently used with carbon fiber because if you're paying that much, you want the best performance possible - this technique is also used with fiberglass, but more frequently, and epoxy type matrix is used that has an exothermic curing cycle so "outside" heat is not required.

Skimmed your post? Not quite. I focus on what matters in an applied sense, as usual. It's pointless to argue irrelevant details such as fiberglass will also yellow because fiberglass is rarely ever left unpainted vs. CF that is usually unpainted. This is why so many CF components yellow. Some even state in a matter of a few months.

Also, I believe you that there may be more advanced ways of making composites that don't require baking. However, this process is probably not applied to parts for cars like ours or anything under 100K for CF. In essence, it's irrelevant because if one was to get a CF part for the Kizashi or any other comparable car, it would be subject to yellowing due to more conventional materials and processes used in manufacturing.
 #27505  by SamirD
 Tue Apr 29, 2014 2:10 am
BxKizashiS wrote:Soooo with reading all you guys posts, carbon fiber is not worth it lol... I might as well get it wrapped or just leave it how it is
To sum it up in one word--yep. :mrgreen:
 #27513  by ~tc~
 Tue Apr 29, 2014 3:20 am
KuroNekko wrote:Skimmed your post? Not quite. I focus on what matters in an applied sense, as usual. It's pointless to argue irrelevant details such as fiberglass will also yellow because fiberglass is rarely ever left unpainted vs. CF that is usually unpainted. This is why so many CF components yellow. Some even state in a matter of a few months.


Once again, you have totally missed the point. The whole discussion was predicated on having the "woven carbon fiber look", and if that is the baseline:

~tc~ wrote:I said if you had clear resin with the fiberglass to have the same look, you would likely have the same problem. Obviously, if you use a nice automotive paint, you won't have the problem.


[quote="KuroNekko"]Also, I believe you that there may be more advanced ways of making composites that don't require baking. However, this process is probably not applied to parts for cars like ours or anything under 100K for CF. In essence, it's irrelevant because if one was to get a CF part for the Kizashi or any other comparable car, it would be subject to yellowing due to more conventional materials and processes used in manufacturing

Actually, the vacuum baking is the most advanced process. I am suggesting a simpler process would be sufficient for body panels, and a UV protective clear coat will take care of the yellowing.

The point to fiber reinforced composites is to get a higher strength - especially when directionality is a factor - at a lower weight. Due to the ability to orient the fibers however you like, you can make the structure very stiff/strong in one axis and compliant in another if that is desirable for the application. But this assumes that he volume of the part is defined by the strength - in a body panel, that is not the case. It has to cover a certain area, and you can only go so thin with current production methods - no matter how much thinner the strength would let you go. Personally, comparing steel fenders to 'glass fenders, I haven't seen much, if any weight difference.

Now, if you were to cut out the metal roof and replace it with a CF roof, that would be a different story. The reduction in the center of gravity and the increased chassis stiffness would likely make a HUGE difference on the handling.
 #27521  by KuroNekko
 Tue Apr 29, 2014 6:21 am
The topic was about getting the CF look and then whether having real CF was worth it. I stated that many CF hoods and accessories yellow from UV damage. Not sure how this was missing the point of the conversation. You're the one bringing up fiberglass and alternative manufacturing techniques that don't apply to actual products for the Kizashi or cars like it.
Regardless of any theoretical or alternative manufacturing techniques, the kind of CF that the Kizashi would have would be susceptible to yellowing. The evidence for this is seen with the complaints among owners of comparable cars and their yellowing CF parts.

Also, I was merely entertaining the possibilities of other manufacturing techniques I wasn't aware of that you brought up. However, given that Pagani bakes their CF in an autoclave, I had little reason to think baking was nothing but the best process given Pagani is among the most obsessive and exclusive manufacturers in the world. Horacio Pagani himself used to be a CF composites supplier to Ferrari and racing teams before designing and building cars himself out of CF.
 #27536  by ~tc~
 Tue Apr 29, 2014 9:57 pm
If you wants the "CF look" (clear matrix woven fiber reinforced composite material) there are a number of fibers you can use that will be considerably cheaper than real carbon fiber, and a number of processes cheaper than autoclaving. You can get a "CF look" hood for much less than a "real" one. It will be a tad heavier and not as stiff, but neither of those is super critical for an automotive hood.

Regardless of what fiber or production method is used, the yellowing is a different discussion, as it is totally dependent on the matrix material, and it's UV stabilization.