CF roof - possible Group Buy

[316i compact]

Ok. Here is what i was thinkin of. I see many people here loving their ti, wanting to make it perfect from every view. I am one of those as well. So, thinkin how to lower the "weight center" of the car(don't know if i say it right, but you get my point), and to make it lighter, and better looking, a Carbon Fiber roof crossed my mind.
It would offer:

• weight saving
• lower center of gravity of the car
• better looks - M3 CSL style

I don't know the weight of the factory steel roof, but i guess the weight saving would be around 15-20 kg, BUT from the upper point of the car,which is what counts more. Driving dynamics would improve a lot, it's not a coincidence that M3 CSL and the M6 have a CF roof.
I also think that the fabricate of a carbon roof will be easy for a company to do, given it's shape.
Wating for your opinions...

[316i compact]

So i vote Yes depending on the price! Waiting for your opinions!

[Bluebimma]

Are you talking about a complete roof? Will this be an overlay or actual cutting of the roof and carbon fiber being installed in its place? The structural integrity of the car will become degraded, not to mention in the event of a roll over, depending on quality, the carbon fiber may break and shoot carbon fiber splinters into the cabin. A carbon fiber sunroof replacement seems like a much better approach to taking weight off the roof of the car. Not sure where to get them, but i believe they are like 200-300$ for the panel and is like 7-12lbs over the stock ~45lbs of the electric sunroof.

[zboot]

Carbon fiber can be very strong. Depending on the thickness used, it could be stronger than the stock roof. So, you'd have as much a chance of getting carbon fiber splinters as having the stock roof shower splinters as well. The issue of structural integrity is still there, though I think that could be resolved depending on where you cutaway at the roof and how the CF one is attached.

Just keep in mind, if you want a strong CF roof (something as strong as stock or stronger) [it will still be much lighter], you are going to pay for it. Just based on the price of carbon fiber stock and the work that would be involved in shaping it for the roof, I'd estimate the cost to be at least $2000.

Check this site out to get an idea for how much carbon fiber costs. Keep in mind that an 11x8 sheet is the size of a normal piece of paper: http://www.robotmarketplace.com/mark...rbonfiber.html

[Philly]

i think it would look terrible..... unless the entire car was made of CF lol

[zboot]

they could paint it so you wouldn't know it was a CF roof.

[bullmand]

I don't see this happening in a non-ghetto way unless you're willing to spend several thousand dollars. I'm sure it's possible, but how much is it really worth? Lower the car, put a CF hood on and be done with it.

[mohaughn]

Umm.. Guys.. It would just be a carbon fiber cover for the sunroof. But even then, replacing just the cover with a CF part will not save you that much weight. If you want to save weight you need to completely remove the sunroof.

[316i compact]

Originally Posted by rwd_king

i think it would look terrible..... unless the entire car was made of CF lol

So are you implying that the M3 CSL looks terrible???? If it is done along with other mods, it will look awesome. But the point is not the looks only, which is based on personal taste. It's the weight saving and improvement in handling.

Here is the diagram of the roof from realoem :

If the CF part is made exactly like the BMW Part (no.1 on the diagram), we don't hurt at all the rigidity of the chassis. We only make it A LOT lighter , in the most valueable point to take off weight. Think of the M3 CSL. I've seen a few M3s using the genuine CSL part.

[316i compact]

For those who have a sunroof this is not possible, unless they want to take out the sunroof or folding top. BTW a sunroof weighs at least 20-30 kg than stock roof.

[mohaughn]

hahaha.. So you really are talking about the complete roof.. How do you plan to attach that? Isn't the stock roof welded into place on our cars?

The CSL only dropped 15 pounds as a result of the CF roof panel. Honestly this isn't possible to do unless each one is custom. It would need to be installed by a highly skilled professional. You are better off just ditching your sunroof, you'll get more weight savings..

[316i compact]

I don't have sunroof anyway. Ofcourse this is going to be done by professionals. Exactly the same way it is repaired when the vehicle is damaged. I dont know if the roof is welded on the chassis (probably it is), but this is doable, if there are willing people to do it.
Vorsteiner sells a CF roof for the M3, for those who think it's impossible.
http://www.vorsteiner.com/vcsl-roof.html

[DustenT]

This is the most ridiculous idea I've ever heard.

Have you ever removed a roof skin? Are you serious?

[316i compact]

Originally Posted by DustenT

This is the most ridiculous idea I've ever heard.

Have you ever removed a roof skin? Are you serious?

I am not working in a workshop, so no. And YES i am serious. But any workshop who's repairing accidented cars, can do it. I don't see why it seems so impossible to most of you, when there are cars around which have done it. It doesn't matter if it is a M3, the procedure would be the same.
CSL only saved 15lbs because M3 standard roof is aluminum, ours not, so expect much more weight saving.

[Bluebimma]

I still say that the CF sunroof panel is a better idea as far as loosing weight off the roof for TI's equipped with the sunroof. Not too sure on the conversion of weight from lbs->kg, but 7-12lbs, or less, is much better than the stock 40-50lbs on the roof. Will this be for a track car or a daily driver? Cost alone for getting the job done right doesnt seem feasible on anything other than a track car. I plan to do the CF sunroof and have it paint matched to the car this summer.