Roof strength

[richie]

I've found a source wiling to make me a carbon bonnet, which is good but i have question.

Strength - a couple of people, who have no experience of replacing a standard roof skin with a carbon one, have said that the car may be unsafe due to the fact that the roof plays an important part in stiffening the chassis, and that i would need a cage to counter-act the replacement.

Now personally i don't believe this as the original material is so thin and flexible i can't see it adding much if any strength to the car as a while. But i have been known to be wrong, occasionally, in the past and in this instance i don't know anyone else who has done this modification to a car and can give me first hand advice as it were.

Maybe a long shot posting on here but someone may know

[oldschool]

I am quite a bit

What has the strength of the bonnet got to do with the roof or vice versa?

To answer the question, whether the original material will add that much strngthening: Yes it does. Thickness of material is not important. The question is how you get the structural integrity going with the shape. If things were as you assume, cars would be even heavier then they are and they would be rather dangerous in impacts (won't go into detail here).

Also you need to consider that the material connected need to be bonded in a way that doesn't allow for separation neither under normal running conditions nor in an impact, which would be fatal.

Spot weld points are strategically positioned to counteract stress problems and to give the structural integrity in conjunction with the shape of individual components of the chassis structure.

I wouldn't advise anyone to alter these. When manufacturers do this (Gallordo SL or M CSLs to name 2) they do not just replace. Their is quite some engineering work to be done, hence the price tag.

[richie]

I mis typed that, i meant it all to be about a carbon roof

I thought you may say something like that.

Cheers for the info.

[lowtechguy]

Is this a weight reduction method or do you just want to have a carbon roof?

Getting carbon doors would make the car lighter than wasting time with the roof imo

[richie]

lowtechguy said:

Is this a weight reduction method or do you just want to have a carbon roof?

Getting carbon doors would make the car lighter than wasting time with the roof imo

Both.

1. I have 2 dents which can't be fixed
2. I have deadening on the roof which weighs maybe 10kg

The 2 companies that got back to me have also said strength is an issue and that they would only provided a skin to go over the original, which is a total waste of time as it adds weight to the roof

I don't want carbon doors and they'll be much more than i want to spend.

[lowtechguy]

have you contacted a coachworks type company? if they can do pickup conversions safely this should be a walk in the park no?

[richie]

lowtechguy said:

have you contacted a coachworks type company? if they can do pickup conversions safely this should be a walk in the park no?

Yes, they said that the roof will need to stay if i don't want problems.

I won't be doing it, the prices i got were £900 and £1150 which is more than i'm willing to pay for a roof tbh That's a very good spec head inc. fitting which will be of more benefit to me.

[lowtechguy]

what about cutting it out alltogether and having a folding vinyl roof like the fiat panda used to have (double sunroof I think they call it)

[richie]

lowtechguy said:

what about cutting it out alltogether and having a folding vinyl roof like the fiat panda used to have (double sunroof I think they call it)

Cristian, i am not a hairdresser.

[lowtechguy]

True, nobody would trust a bald hairdresser