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Discussion Starter #1 (Edited)
Hey....

I just want you to think twice on purchasing and installation of CF fiber hoods. :confused3

I would like to have one of CF hood, if it is as safe as the factory hood. Even if OEMs are heavier, they are designed to absorbs crash forces and bent in a way that would not harm what's beneath it, or the passengers inside the cabin.

I personally experienced it when I had front-end collision w/ Suburban. :crying: I happened to crash my 540 into its tail side tow bar, and since I was at my full braking (front lowered), the bar hit between the dirver's side front light and the grill, not the bumper. The right side of the hood was half folded, so I had to replace it, but it didn't do much to anything under the hood, nor to me. ;)


If I had CF hood installed, could it give same level of protection that OEM hood gave me?; probably not. CF is too strong to absorb crash forces. Some of you might have never had an accident, and all of us don't have any in our future plan, but Who know's what's going to happen? hmmm

So I just want all of you to think once again before installing CF hood. It is your option, but I do not think it is worth neither the money nor your safety.

Thanks for reading,
Good luck...

:typing:
 

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Thanks MUM.

With a name like Warpspeed, your concerned about accidents??

Next you'll be telling us not to speed because its dangerous.

Moding you M5 is also dangerous. Why on earth would any sane person want to make it faster. Why tamper with the brakes. You have to use them all the time.:rolleyes:

I understand your point, but their are far more dangerous mods than a C/F hood.

How come you didn't bring up the guy with the honda civic who was decapitated in an accident with his C/F hood.

This is a Race car hood. Races cars have more accidents in one season than all of us on the board put together.

If its safe enough for them, thats good enough for me.

But thanks for the concern, MotherNeed4Saftey. :byebye:
 

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I don't think the hood offers any crash protection. Here are som pics when I crashed at around 60 mph with a E39 525i:





Interiour all fine. Me and Johan too BTW :confused3
 

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That picture is testament to the safety built into the E39 - but, off topic - Gustav, did that Evian bottle stay in the cupholder during the crash?!?!? Maybe the cupholders are better than we thought :biggrin:
 

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cf hood crack upon impact, so it's safe to say that they offer less protection than the regular hoods.... but from looking at the pictures above, not sure how much protection the regular hood provides in the first place... hiha hiha

Anyhow, I think in the event of a front impact, the frame of the vehichle absorbs more of the energy, so the hood shouldn't matter that much...
 

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Yes the cupholders worked great :haha:

The other car flipped over on the roof, and he had a broken arm. Thanks god he didn't have a passenger. Then it would have been a tragedy.

In anycase, wearing a seatbelt, seatbelt tensioners and an airbag is you best life insurance.

If this would have been in an E36 3 series I might not have been so lucky.

Lessons learned: never trust that other drivers follow the traffic rules. Lesson two: bring a license with you when driving in Germany, otherwise they you'll have to deal with lawyers for years after... But case is closed, at last they accepted what I said all the time: I have a license and I just didn't bring it with me.
 

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Ahhh Gustav,

But you missed one...

A full rollcage with GT3 seats and a five point harness will do wonders for safety as well, even in an E36 3-series.

Just my theory.;)
 

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Re: Thanks MUM.

MIB said:
With a name like Warpspeed, your concerned about accidents??

Next you'll be telling us not to speed because its dangerous.

Moding you M5 is also dangerous. Why on earth would any sane person want to make it faster. Why tamper with the brakes. You have to use them all the time.:rolleyes:

But thanks for the concern, MotherNeed4Saftey. :byebye:
I dont see the need for that tone in your writing. Dont be a jerk. Warpspeed is seriously voicing a concern for safety.
 
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Some Facts about Carbon Fiber

Some Facts about Carbon Fiber

1) Advanced composites, such as carbon fiber, (e.g. Kevlar), absorb five times more energy
per pound than steel, and they absorb energy more smoothly.

2) Materials and design are much more important for safety than mere mass, as any bicycle helmet will illustrate.

3) Formula One and Indy race cars are made of advanced composite materials, not only because their light weight improves acceleration and handling, but also because they provide the ultimate in driver safety.

Cheers.
 

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warpspeed,

i think that your concerns are for the most part invalid for several reasons. first, the way your hood performs in an accident is going to have little effect on the passengers within the car. the hood is attached at two fairly fragile points (when considered in the context of the forces generated by a crash) that, if the hood were not to crumple for some odd reason, it would most likely just tear right off the hinges and fly off the top of your car. that being said, the hood will crumple. dont confuse the fact that, although carbon fiber has something like 10-100 times the "tensile" strength of steel, it is not necessarily as strong as steel. although the previous two statements sound contradictory, allow me to clarify. as a composite, carbon fiber's strength really depends on the way it is laid up. in short, i doubt any hood you buy will have the structural integrity of a formula one monocque tub. bottom line, GO BUY THAT CARBON FIBER HOODS AND POST UP SOME PICTURES!!!!!!!!!!!:)

Ernie
 

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Discussion Starter #12 (Edited)
Well,

MIB,
I understand your point, but their are far more dangerous mods than a C/F hood. This is a Race car hood. Races cars have more accidents in one season than all of us on the board put together
Yes, I totally agree!! but the other mods won't break into your windshield at the time of certain front collision. unless u have installed that Rolls emblem.;) Also race cars have front pins that assure the attachment. Some races even require Lexan or composite made windshield, which is different from what we have.

Gustav,

I don't think that the OEM hood offers any protection, either, but even in your picture, the hood is collapsed and folded in a way that doesn't do harm to its passenger.... was that a renter?

Tfung,

that's the point!! CF hood actually cracks upon front collision, and it won't be stay at the hook because the material is too strong. If I had the CF hood at the time of accident, I just can't rule out the possibility that sharply cracked hood would have went thorough the passenger cabin.

DDM5,

1) yes they are, but in case of excess forces applied, it would simply crack and can produce sharp edges. also strong nature of the material lets the hood tear off from the mount more easily. I would strongly recommend you to have one of those double front race pins if you are serious about installing them.

2) yes they are. but my point is that OEMs are designed to collapse and folded to distribute crash force diversely.

3) They all have roll cages under their body part. they do not have huge, crackable "after market" hood in front of them.

Alpina b3,

yes, again CF hood will more likely tear off from their "fragile" mounting and it can harm the passengers!!


I just wanted to say that CF hood might harm you at certain types of front end collision far more than OEM will. OEM hoods are heavy, but they are designed in a way that.....

Once again, it is your decision. I would want to shave off few pounds by adding CF hood, if I have modifications like DDM5 have. Then I bet it will make a difference, particularly a front heavy car like M5. But otherwise I think that it would not worth it considering a possible damage you can have from installing it.

Well, maybe I'm a little too concerned. I felt that I need to say this because I thought that I should, based on what I know..I reaaalllyy want to have CF hood and shed some pounds off if CF hood is as safe as OEM hood. twice again, It¡¯s just my opinion, and your decision.
 

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Most hoods are designed specifically to prevent cabin intrusion in the event of an accident. They usually have specially designed hinges that minimize the chances or, in some cars, even go further than that. The Toyota Supra has hooks mounted in the base of the hood that grab onto the chassis if the front of the car is pushed inward. The force will fold the hood upward along creases in the hood's frame, effectively creating a shield that not only prevents the hood from entering the cabin, but other debris as well. I'd be very surprised if any manufacturer actually said that their hood was a structural safety component.

I think the concerns are legitimate, but there's no discerinable conclusion. Hoods are designed to behave a certain way in the event of a crash and replacing the material could change that, either positively or negatively. alpina b3 has a point -- the strength of carbon fiber in a particular application doesn't mean that it is a superior material in every application. Where the steel might crumple and fold, the carbon fiber might just bend and store up that energy. Or it could shatter. Or its strength could shear right through the hinge mounts. Only a structural engineer with experience in carbon fiber design could tell you more. Just remember that balsa wood has a greater strength-to-weight ratio than steel, but I wouldn't want a car made of balsa wood!
 

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WarpSpeeD said:
Well,

MIB,


Yes, I totally agree!! but the other mods won't break into your windshield at the time of certain front collision. unless u have installed that Rolls emblem.;) Also race cars have front pins that assure the attachment. Some races even require Lexan or composite made windshield, which is different from what we have.
Hi Warp, didn't mean to sound like a jerk as DeWitt put it. (How is a smiley wave bad tone?)

We have put alot of effort into getting our group buy off the ground. If we didn't believe it safe, we wouldn't be buying them.

There is a Well know champion race car driver here called craig Lownes. He was involved in a bad accident on the circuit, and his feet were crushed. Not too badly, and hes ok. Now they have encased his foot well in a C/F box. Now I don't think they would do that if there was a chance that the C/F would shatter and cut his feet off.

Yes, everything is possible in accidents. But the probability would be extremely rare.
 

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Gustav, Hows your ears.

I've heard that when the airbags go off, the instant pressure change makes your ears pop.

Did the airbags make a loud bang and give you a fright. Probably no louder than the bang of impact.

Did you feel it hit your face.? Sorry for all the questions, I've had airbags for years and never ever seen one go off. Probably a good thing. Although my 540i airbag light has just come on.

Which reminds me I'll have to call the dealer. Chow. :)
 
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Hey MIB,

Your point about the CF enclosure for the drivers feet is a good case-in-point. Also worthy of consideration is that the Lotus Esprit has been made of Fiberglass/Kevlar for the past 25 years, and I would have thought that if it were especially dangerous something would have been mentioned over the past quarter of a century.

I do think that I will personally get hood pins for my CF hood, as I like the look and also think that they will hold the hood down more firmly at very high speeds.

Cheers.
 

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Certainly the safty issues associated with a non-steel hood have been addressed by 50 years of corvette production. I realize the corvette is not made of CF, but it is a good example none the less.

Mark
 

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Hi guys. Warpspeed, ah now I see your point. Didn't think of that before.

MIB, they are fine. I think the airbag sound wasn't the big thing, the thing that was loudest was the "meeting" of a couple of 3-4 tons of metal flying through the air :) But it gave me a slap sure. My thumbs felt it a bit though since they got the punch of the airbag.

Yes it was a rental from AC Schnitzer. The car we rented after that was a 7 series hiha
 

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MIB said:
We have put alot of effort into getting our group buy off the ground. If we didn't believe it safe, we wouldn't be buying them.

There is a Well know champion race car driver here called craig Lownes. He was involved in a bad accident on the circuit, and his feet were crushed. Not too badly, and hes ok. Now they have encased his foot well in a C/F box. Now I don't think they would do that if there was a chance that the C/F would shatter and cut his feet off.

Yes, everything is possible in accidents. But the probability would be extremely rare.
I think his concern is legitimate... while you guys did put in a lot of effort for the group buy, it is only prudent to know what will possibly happen... While the event of something really bad happening with the cf hood is rare, it is a possibility and people should be informed before making a purchase... some people may think that it's worth the 50lbs in weight savings to be worth the extra 1 in a thousand chance of getting killed by a cf hood... but some people might think that it's not worth the risk....

Race cars builders spend millions of dollars on R&D, and I'm sure they spend a lot more than what we are spending to make cf hoods for the M5... and I'm sure the box they use for his feet have been extensively tested... I don't think we can claim that for the cf hood that the group buy is getting....
 

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I've heard that when the airbags go off, the instant pressure change makes your ears pop.

Did the airbags make a loud bang and give you a fright. Probably no louder than the bang of impact.

Did you feel it hit your face.? Sorry for all the questions, I've had airbags for years and never ever seen one go off. Probably a good thing. Although my 540i airbag light has just come on.
Hit a stump at 35mph in my 98 540i

There was no discernable difference in sound between the collision and the airbag going off. My windows were up and I got a slight pop and ringing in my ears.

I don't recall hitting the airbag but the small bit of blood from my [rather large] nose was a testament to that fact. I then noticed that the lights in the cabin went on and the windows rolled down to clear the powder from the airbag that was floating in the air.

My hood also collapsed nicely and stayed attached. The only other thing I remember is that my 32oz drink cup was still in the cup holder, but the contents were all over the windshield and headliner. hiha hiha

As someone stated earlier, it's all in the design and how the CF is layed up. I've seen CF hoods with scoring on the underside that is there to focus the forces in in the correct manner, in escence doing the same thing the OEM hood does. If it gets hit, the first thing to go is the crease. If it tears, at least it tears in an orderly fashion.

Good luck with the group buy!

allan
 
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