Carbon Fibre Roof

Mon Jun 02, 2008 8:29 pm

I've got a contact who can make E30 carbon roof skins, idea is to cut out heavy and / or rotten sunroof and bond this in place. It is very strong once done and looks brilliant. Need five orders to get the price of £295 each, about a month to make them once I've given them a perfect non sunroof example to copy. Will fit E30 saloon and M3 with the back edge trimmed off.

Tue Jun 03, 2008 1:36 am

ummmmmmm

take its just a case of old skin off and reseal new one on ?

Tue Jun 03, 2008 9:17 am

Um.. Caged cars only tho yeah?

Tue Jun 03, 2008 12:45 pm

Suppose caged would be "safer"

Tue Jun 03, 2008 12:52 pm

Yes, just a case of cutting out the old one and using a good quality bond / dealer like sikaflex to stick the carbon roof on. Because the roof is made shaped it fits really well and doesn't need rivetting in place as well.

Tue Jun 03, 2008 8:22 pm

Touring ?

Wed Jun 04, 2008 1:18 pm

Must admit didn't think that there would be much interest in one for a touring but can ask. How much longer is a touring roof that a saloon?

Wed Jun 04, 2008 9:56 pm

defo for touring

Wed Jun 04, 2008 10:09 pm

Dread to think how flexible that would make a car that didn't have a cage!

Everyone go the the fridge and grab your marg tub with one hand at each end and the lid on. Try to twist the tub and you'll notice it's relatively good at resisting the torsional loading you're putting into it.

Now take the lid off and repeat the twisting experiment and notice just how poor the tub is at resisting the twist.

If you couldn't attach the roof as firmly as the factory did, you're driving around in a lidless marg tub

Of course if you're just using it to offset the weight of a cage then all it need be is water tight.

Thu Jun 05, 2008 6:33 pm

Can you put me down for a provisional yes, (2 door saloon, non m3)

Cheers,

Michael

P.S. I'm in no rush, don't really need it till August.

Thu Jun 05, 2008 7:07 pm

Turbo-Brown wrote:Dread to think how flexible that would make a car that didn't have a cage!

What i was thinking was i would probobly add a couple of diagonal C/F ribs aswell. I was thinking of making them by sticking stripps of 25mm x 10mm foam to the roof skin then laying some C/F tape over the top ??

Like this below, unless there's a material that has more suitable properties ? Kevlar or Kevlar-C/F hybrid ?

http://www.ecfibreglasssupplies.co.uk/s ... p-641.html

Thu Jun 05, 2008 7:29 pm

Kevlar-C/F hybrid won't splinter in an accident and crash and is stronger and cheaper, tape won't bond well enough though and won't become strong enough to supply structural strength.

CF splinters under pressure and I wouldn't fancy hard shards of CF around my face and head if I wasn't wearing a full face helmet. Probably worth noting that I doubt any insurance company would touch you if you declared you'd chpped most your roof out, so track cars only I reckon.

Thu Jun 05, 2008 7:32 pm

Tape won't bond correctly because its just CF with sticky crap underneath, the CF isn't actually impregnated with resin so doesn't cure as solidly as CF that is. Laying up CF isn't that hard anyway just buy some and some clear surfboard resin. All available on ebay.

Thu Jun 05, 2008 7:57 pm

I didn't realize that it was sticky sided, thought is was just like normal raw C/F. I was thinking sand the roof skin to aid it sticking and lay it on with a suitable resin like you say.

Thanks for the info, especially about the Kevlar-C/F hybrid.

Thu Jun 05, 2008 10:11 pm

It's more the bond to the remaining structure of the car which would either make or break the torsional rigidity.

As a stiffening membrane, the CF skin would probably do a good job.

Going back to our marg tub analogy, the lid itself is extremely flexible in it's own right, but when secured around it's perimeter it adds immense stiffness to the structure of the tub.

Thu Jun 05, 2008 10:26 pm

Always fancied building an E30 325i Sport CSL,

In fact I have more than thought about it

, at the moment all my money is going into an engine build though.

Fri Jun 06, 2008 3:02 am

I think if it was sufficient thickness and was bonded on with a high quality epoxy it'd make the car equally stiff or even stiffer than the standard roof.. You'd have to make sure it was done without residual stresses when the car was loaded (on the gound).

Plus the weight reduction that far from the roll axis of the car would have an extremely good affect on the handling.

I WANT.

Shame I cant afford. One of these and one of Demlots bonnets is on my christmas wish list. Not gonna happen though...

Fri Jun 06, 2008 3:02 am

Why have I always other stuff to spend money on when these things come up!!!

I'm getting rid of my heavy sunroof and putting in a right climbing frame inside my track car so this thing would be just perfect.
AND my roof skin is rusty undeneath

And it's a white car too so would look pretty cool, lol.

Price isn't too bad either if it's quality piece as in strength etc.
I wonder coulld it be made with some sort of a lip underneath the edges of the interior so that some sort od strip could be welded onto the roof rails and bolted to the CF roof to get abit more of a hold than just bonding...

Sat Jun 07, 2008 12:46 am

if it's bonded well it'll be stronger than a few spot welds!

Sat Jun 07, 2008 4:18 am

I really want a carbon roof for my touring!!!!!

Been thinking about it for quite a long time now, but i'm not too sure!!

Must give a brilliant effect to the handling though - lowering the centre of gravity a lot!!
Would be interesting to know what the steel roof skin weighs, compared with the CF skin!!

How do BMW bond the roofs onto the CSL??
I'm sure it could be done just as well as a few welds, as long as someone knew what they were doing!!
(I'm assuming E30 roofs aren't seam welded?)

But would it splinter if the worst happened and you rolled it??
In a car with no cage, would it be as safe as the standard tin top??

Would look awesome though!!!! Once i've CF'd my front end, this will definately be added to the bottom of my list somewhere!!! I just worry that the looks would win me over and i'd be racing around in something not as safe as i think it is!!!!

Sat Jun 07, 2008 7:05 am

miniblob wrote:
But would it splinter if the worst happened and you rolled it??

From what I gather, if you laminate a layer of Diolen into your panel, it acts like the laminate interlayer in your windscreen so that material either side (glass, CF or whatever) can break but the bits are still held onto the interlayer and shouldn't fly around causing harm.

Sat Jun 07, 2008 8:46 am

Oh, God every time I look at this thread I want one more and more.

Was going to go for CF front panels but in fairness it would make so much more sense to cut the roof out, fit the cage and then put one of these on before the car goes anywhere....
Would be easier to work inside the car and also I'd probably get a much tighter fit with the cage

Don't ye all agree

Yep, going to have to get one

Sun Jun 08, 2008 3:22 am

Turbo-Brown wrote:
miniblob wrote:
But would it splinter if the worst happened and you rolled it??
From what I gather, if you laminate a layer of Diolen into your panel, it acts like the laminate interlayer in your windscreen so that material either side (glass, CF or whatever) can break but the bits are still held onto the interlayer and shouldn't fly around causing harm.

Like your thinking!!!!!

Very tempted - may well go for one in the future - gotta get it on the road again first!!!

Sun Jun 08, 2008 3:30 am

Dave_M3 wrote:Oh, God every time I look at this thread I want one more and more.

Was going to go for CF front panels but in fairness it would make so much more sense to cut the roof out, fit the cage and then put one of these on before the car goes anywhere....
Would be easier to work inside the car and also I'd probably get a much tighter fit with the cage

Don't ye all agree

Yep, going to have to get one

Yes IMO a CF roof will make much more of a difference than lightened front panels (centre of gravity!)

Sun Jun 08, 2008 3:30 am

Turbo-Brown wrote:
miniblob wrote:
But would it splinter if the worst happened and you rolled it??
From what I gather, if you laminate a layer of Diolen into your panel, it acts like the laminate interlayer in your windscreen so that material either side (glass, CF or whatever) can break but the bits are still held onto the interlayer and shouldn't fly around causing harm.

spot on Alex!

Sun Jun 08, 2008 4:23 am

How far out to the edges will thise go actually???

Was looking at the roof today and seeing how it would fit in.
Thing is when the E30 roof is so curved at the edges and has no strips along the sides like the one in the pic, where do you have the line between metal and carbon...

For some reason, I mis-read the first post too and got it into my head that they were going to take a few months to make

Probably just distracted by the pics

Wed Jun 18, 2008 3:40 pm

yeah i am kinda interested but wondering where the metal to carbon meet would be? top of the pillars? front and back windows etc, ???

Fri Jun 27, 2008 4:22 pm

When you remove a roof skin fully, you remove the guttering aswell, and down to the braise on the a and c pilllars

A new skin then sits on the lip of the shell and you spot weld the gutter to the lip on the shell

If this skin is the same as a BMW roof skin then i'd guess you could bond the entire length of the lip, ie the cf gutter rail, then all round the screen at the front and back

Not sure how it would meet the pillars though

All just guess work based on experience with reskinning with metal roofs

Fri Jun 27, 2008 5:28 pm

I reckon, I could end up painting mine if I'm not that happy about where the line between carbon and steel meet, lol.

Would be nice to get something like the E46 or E92 roof but not sure would it be possible on the E30

Sat Jun 28, 2008 9:20 am

I've sorted a non-sunroof skin for the guy to work on now, waiting to see if he can get a good finish on the edges. I'll keep everyone updated, Andy

Sun Jul 20, 2008 10:13 pm

im definately interested mate cus im prob gonna be cutting my roof off to fit a multipoint international cage, so this would be perfect what kind of price is expected?

Fri Oct 17, 2008 10:10 pm

Has anything happened with this yet? Would definatley be interested if i could see the quality of it first, have the perfect car to fit it to now....

Sun Oct 19, 2008 12:54 pm

im also looking for one of these..whats happening with them

Thu Nov 20, 2008 10:34 am

Good post!! would get one if wasn't buying a cabby

could you get the horse shoe made in CF?! that along with the bonnet and boot

Guess that car in the pic.. Me thinks its a mk3 fiesta!

Fri Nov 21, 2008 9:11 am

These are very unlikely to happen now. The guy I had to do them does a lot of motorsport parts and now has a big contract with a team so small runs aren't possible now. Also I know that the guy with the fiesta that has one fitted had some "flex" problems and had to have some extra bracing put on his cage to stop it.