BMW M5 Forum and M6 Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
747 Posts
Discussion Starter · #1 · (Edited)
I wonder what BMW has done (differently from Porsche) to keep the Carbon Fiber roof on the new M3 from yellowing. I know a lot has to do with the CF supplier and the amount of stabilizer they use in making the CF. However, if the CF on the interior of Porsche's most expensive car is yellowing from exposure to sunlight, I can't help but wonder what will happen to a roof that is constantly exposed? I'd hate to start off with a black and grey CF roof that ended up black and yellow after a few years.

And, if they haven't addressed the issue in advance, I wonder would it be covered under the maintenance or body warranty?

See page 2 of the attached link for some photos of some yellowing CF on the Carrera GT. I guess buying a yellow M3 would solve that problem; at least it would fade to match.

http://forums.rennlist.com/rennforums/showthread.php?t=364648
 

·
Moderator
Joined
·
4,398 Posts
...

as a last resort look into what clear coat is most effective in preventing UV damage

...VRAlexander wasn't kidding about the yellowing: http://www.ecacp.com/showroom.aspx you can see it in the add for his car

i guess the guys at ceaser's palace weren't too familiar with alexander's videos when he traded them the car, because that things been sitting for about 2 months now
 

·
Registered
Joined
·
632 Posts
Don't really understand how sun exposure can have anything to do with it - the trim pieces under the roof and on the doors can't get much UV exposure?

And does it really look so bad on the CGT that was featured?
 

·
Registered
Joined
·
747 Posts
Discussion Starter · #4 · (Edited)
Don't really understand how sun exposure can have anything to do with it - the trim pieces under the roof and on the doors can't get much UV exposure?

And does it really look so bad on the CGT that was featured?
I think many agree with you that it doesn't look so bad. However, if I payed half a million for a car, having different trim pieces start changing color on me would piss me off as well. Actually, the photos on page 7 show some side by side pieces of what it should look like versus those that have suffered the UV damage. There's also a good description near the bottom of the same page of how the sun exposure damages the resin in the CF. It appears to be preventable if sufficient stabilizer is used. I only posted this in hopes that BMW doesn't let the M3 roof suffer the same issue. The strange part is that it appears some of the parts are changing color even though they are not directly exposed to the sun. It's got to be an issue with the manufacturing process in some way although I'm not a CF guru by any means. By the way, the new Corvette ZR1 is going to have similar CF pieces exposed to the sun but look under the "Hot Wheels" section of the attached Edmunds article. They are quoting something like $60,000 per gallon for the UV stabilizer. Although only 3% is used ($2000), this probably explains why some CF manufacturers may shortcut this additive.

http://forums.rennlist.com/rennforums/showthread.php?t=364648&page=7

http://www.edmunds.com/insideline/do/Features/articleId=124018
 

·
Registered
Joined
·
543 Posts
Easy answer - they cant keep it from doing that, so it needs to be replaced after a certain period of time.

I am not saying this is the case, I am saying its the worst case scenario - maintenance part.
 

·
Registered
Joined
·
747 Posts
Discussion Starter · #7 ·
ummmm, E39 forum is for E39 info...:confused2
I'll help clarify your obvious confusion. Don't get hung up on the title. The issue is carbon fiber degradation, which is applicable to any owner that considers using it. This includes e39 owners.

I only added the M3 because it's use is in such a prominent location. If you don't have or plan to use CF, then obviously this thread doesn't apply to you. Others that do or are considering using it may find the information of interest. IMO.
 

·
Registered
Joined
·
308 Posts
I'll help clarify your obvious confusion. Don't get hung up on the title. The issue is carbon fiber degradation, which is applicable to any owner that considers using it. This includes e39 owners.

I only added the M3 because it's use is in such a prominent location. If you don't have or plan to use CF, then obviously this thread doesn't apply to you. Others that do or are considering using it may find the information of interest. IMO.
good point...maybe we should have Gustav consider a sort of 'show & shine' section..
 
1 - 8 of 8 Posts
Top