22 replies to this topic

[covjamie]

thanks

[Body stylist]

Compared to what? lol

no they are not dangerous

[Burnard]

If you mean in a crash.
Yes they are more dangerous to have than a steel front end as they provide very little impact resistance as they just smash appart.
A steel front will custion the blow as it crumples before there is any impact on the subframe and engine where as a fibre front will splinter instantly and the only thing between you and what you hit is the solid subframe and engine. which will either bring you to a very sudden hault or come into the cabin posible causing damage to your feet, legs, and your chest if the steering wheel moves far enough.

Saying that, the difference is minimal as there is only about 4 inches over hang of body work infront of the subframe which is really a tiny crumple zone.

To be honest if you are asking because you are thinking of fitting a fibreglass front, then just fit one, The difference will be hardly noticeable in the even of a crash bad enough to cause that sort of damage.

Chris

[mini93]

If you mean in a crash.
Yes they are more dangerous to have than a steel front end as they provide very little impact resistance as they just smash appart.
A steel front will custion the blow as it crumples before there is any impact on the subframe and engine where as a fibre front will splinter instantly and the only thing between you and what you hit is the solid subframe and engine. which will either bring you to a very sudden hault or come into the cabin posible causing damage to your feet, legs, and your chest if the steering wheel moves far enough.

Saying that, the difference is minimal as there is only about 4 inches over hang of body work infront of the subframe which is really a tiny crumple zone.

To be honest if you are asking because you are thinking of fitting a fibreglass front, then just fit one, The difference will be hardly noticeable in the even of a crash bad enough to cause that sort of damage.

Chris

so uv had a crash in both then yeah? look at crocks mini where it crashed at the ring into a barrier, front end was still usable...ok it was a carbon front and as such a FG wouldnt be as strong but it only depends on how well laid up they are in the 1st place

[Ethel]

Fibreglass can be at least as strong as steel - they made bumpers out of it. Plastic resins behave differently, mild steel will absorb energy by deforming (the crumple of crumple zone). GRP is much more elastic and will spring back in to shape; if it's bent beyond its elastic limit it breaks releasing the stored energy.

The issue isn't really the material used as the ability of the structure to dissipate the impact force, many flip fronts are only connected to the car by 2 narrow hinges and a few quick release fasteners.

[dave21478]

^^^ this is the correct point to think about. The difference in strength between the actual fibreglass panels and the steel panel isnt that important - what is important is entirely removing the welded-on steel which provides a crumple zone, replacing the suframe mounts with some box section that direct the forces from even a relatively minor shunt in ways the rest of the shell was never designed to receive, and hanging the fibreglass in place using gate hinges and a handfull of dzus clips.

[Sam Walters]

So your telling me that the front of the subframe in a mini is properly supported by using a steel front end?

[Sam Walters]

That would be a fiberglass front end with a carbon backing, unless he`s spent 400 pounds on it. like some companies are willing to charge.

[panelbeaterpeter]

If you fit a fibreglass front end with good quality brace bars, then there's no reason why it wouldn't be perfectly safe. Like has been said, there wouldn't be a crumple zone, but I would have said that if you have an accident bad enough for that to come into play, then you're pretty much screwed anyway.

[dave21478]

Not necessarily. Just a couple of days ago in the general chat forum, some chap put up pics of a front end shunt in his car that had a fibreglass flipfront. The brace bars channeled the force from the impact directly into the upper bulkhead corners, scuttle and a-pillars and wrecked the shell. Chances are - and I say "chances are" as nothing is certain and Im no crash investigation expert - that if he had the standard welded on front then the impact would have wrecked the front panels, but the rest of the shell would probably have come out better off.

[panelbeaterpeter]

I see your point, the force would be concentrated.

[captainjack15]

Not necessarily. Just a couple of days ago in the general chat forum, some chap put up pics of a front end shunt in his car that had a fibreglass flipfront. The brace bars channeled the force from the impact directly into the upper bulkhead corners, scuttle and a-pillars and wrecked the shell. Chances are - and I say "chances are" as nothing is certain and Im no crash investigation expert - that if he had the standard welded on front then the impact would have wrecked the front panels, but the rest of the shell would probably have come out better off.

That's true!

But whats more dangerous?? Depends how quickly your going in the first place, the bars being pushed up and ruining the shell if better then the engine etc being thrown into the cabin!

But hey I dunno!

[covjamie]

FIBREGLASS FRONT END HERE I COME !!!

[RacingGreen]

Not necessarily. Just a couple of days ago in the general chat forum, some chap put up pics of a front end shunt in his car that had a fibreglass flipfront. The brace bars channeled the force from the impact directly into the upper bulkhead corners, scuttle and a-pillars and wrecked the shell. Chances are - and I say "chances are" as nothing is certain and Im no crash investigation expert - that if he had the standard welded on front then the impact would have wrecked the front panels, but the rest of the shell would probably have come out better off.

Yes, but also there is a chance that the metal front, could push the subframe back, and crumple the floor where the rear mounts are.

Every crash is different, it depends how hard and where the front is hit. Whichever way you look at it, the subframe will take alot of the force of the crash unless it is a very light touch. I think steel front/fibreglass front is irrelevant in this case, if the front is hit hard enough to do major damage, then the subframe is more than likely going to damage the floor.

[dave21478]

Absolutely, there is no way to predict what will happen in a crash, and having a welded on front is by no means a guarantee of being safer - especially since there are plenty of minis out there that have had the front panels replaced in a fairly half-hearted style. However, cutting off the front of the shell will definately have an effect of the distribution of forces in a crash - this is undeniable. The exact effects are unpredictable and since (to my knowledge anyway) there has never been any proper investigations and crash testing done on flipfront minis, nobody can state FACTS either way.
It all comes down to personal opinion, and my opinion and my limited experience in the matter says that there is no way in hell I would run a flipfront. Minis are not particularly safe cars at the best of times, and if I am going to have a frontal impact, I want as much foldable, welded on steel infront of me as possible to absorb and dissipate as much energy as possible. Something fibreglass wont do.