carbon fiber vs steel hoods

[AUDILUX]

I have a Fiber Images (full CF) hood on my car and notice that at speed air gets underneath it a little near the headlights and makes it look like it wants to lift off. Of course, since it is latched I'm sure it will never do that. But it does say on many retailers sites that CF hoods are not to be used w/out pins. Was just wondering what everyones' experience has been with their hoods.

I'm thinking of switching back to a steel hood. What do you guys think?

[spokismB5S4]

well you just scared me. Shit

[infinkc]

ive always pined my cf hoods. or put some type of other safety strap under the hood. Ive seen many cf hoods fail.

[Capt. Obvious]

What you're experiencing is the very reason why you should be using pins with your carbon hood. If you're going fast enough and/or there is a defect in the hood where the latch bolts in, there's a good possibility your latch could pull out of the hood.

[The_Auto_Tech]

Yea, I've seen quite a few instances where the latch mount actually cracks and pulls out of the hood.

[JEENYUS]

i didnt know you could even run the CF hood without hood pins.

[RedB5S4]

i didnt know you could even run the CF hood without hood pins.

I didn't know you could run a carbon fiber hood on an S4. Unless, of course, you have a purple widebody sedan

[Marioh]

You'll definitely want pins. If you look at how the OEM latch is attached on the hood... there's not much holding it there.

[AUDILUX]

I didn't know you could run a carbon fiber hood on an S4. Unless, of course, you have a purple widebody sedan

Or yellow (see 3mortal) ;)

But seriously, there are several on the forums running CF hoods...all with pins though?

[SEXICÄN]

not the thread jack, but anyone run a aluminum hood over the stock one?

[034Motorsport]

Or yellow (see 3mortal) ;)

But seriously, there are several on the forums running CF hoods...all with pins though?

What about me?


If you are in need of hood pins just let me know. We have them in stock.

[JEENYUS]

not the thread jack, but anyone run a aluminum hood over the stock one?

they offer aluminum hoods? geez learning so much today.

[michael66899]

INSTALL PINS NOW, the latch will rip out and you will be very pissed off. I've seen some pics somewhere of it happening to a Imola car and it caused a lot of damage. Here's mine.

[michael66899]

Found it,

[Gumby]

not the thread jack, but anyone run a aluminum hood over the stock one?

All C5 A6's and allroads have aluminum hoods from the factory :)

[ThePeoplesChamp]

I have some aerocatch Hood pins if u want. I decided to not use a cf hood

[Das General]

I run pins, no stock latch.

[BITRBO]

All C5 A6's and allroads have aluminum hoods from the factory :)

To quote a line from the best movie ever: "That's fucking interesting man..."

Are you for serious though?

[CruzS4]

holy shit it took out the windshield AND sunroof on that imola, not to mention thrashing the hood. yikes

[DESPOT D S4]

^ and the roof

[Das General]

holy shit it took out the windshield AND sunroof on that imola, not to mention thrashing the hood. yikes

Back in the day it happened to the AWE project car.

[s4andtls]

They make real cf hood pins

[Gumby]

To quote a line from the best movie ever: "That's fucking interesting man..."

Are you for serious though?

Umm.... Yes?

[BITRBO]

Umm.... Yes?

Have any idea what the weight difference is?

[audikidS4]

Hood-pins for the win



http://s4.photobucket.com/albums/y12...5%20CF%20Hood/

[Mantis]

Have any idea what the weight difference is?

Enough that you have to slam the hood on my A6, while I kinda just let the S4 hood drop and it catches.

I would guess 25-30% weight savings

[Soul Kitchen]

What about me?


If you are in need of hood pins just let me know. We have them in stock.

Damn. Sexy car man, shit looks mean!
I am looking into getting a CF hood, as the paint on my stock hood is fucked up even after a proper wax. Had some rotting fruit on it for about a month while I had it parked behind my house, All while I was out of the state...

It seems like a good investment, and is seriously cheaper than a new paint job.

[BITRBO]

Enough that you have to slam the hood on my A6, while I kinda just let the S4 hood drop and it catches.

I would guess 25-30% weight savings

I can see that as kinda of annoying, but anything to lighten up the front end on this car is worth it to me... The car nose-dives pretty bad on hard braking and it really needs heavy springs up front, but some weight loss wouldn't hurt either

[Sfarooq]

Just curious, but did you read your own question? You observed that as speeds increase, your CF hood, which weights slightly/significatly less than stock (dependant on type of CF hood you have), tends to "lift off". I'm not a genius, but I'd imagine that hoods aren't suppose to do that! So why wouldn't you mitigate the risk of your hood "lifiting off" and perhaps endagering you, your car, and other drivers on the road by putting on pins? Just saying.

[AUDILUX]

Just curious, but did you read your own question? You observed that as speeds increase, your CF hood, which weights slightly/significatly less than stock (dependant on type of CF hood you have), tends to "lift off". I'm not a genius, but I'd imagine that hoods aren't suppose to do that! So why wouldn't you mitigate the risk of your hood "lifiting off" and perhaps endagering you, your car, and other drivers on the road by putting on pins? Just saying.

The hood doesn't "lift off" but you can see it move slightly at the corners. The center latch seems rather secure. But yeah, I'm either getting pins or going back to a stock hood.

[spokismB5S4]

To quote a line from the best movie ever: "That's fucking interesting man..."

YES!

and i have a cf hood painted black. I rlly don't want pins cuz they look to ricey but shit... i might have to get them.

[spokismB5S4]

I have some aerocatch Hood pins if u want. I decided to not use a cf hood

ygm

[joe@vwvortex]

I bought my S4 with the CF hood (and front fenders) so I'm not sure what brand it is - but it is unreinforced and it flops around a bit. Fit isn't great but I think that is due to how the pins were installed. It's super light though and that's all I care about since the car is my track car. I also like the vents to keep things cool.

[AUDILUX]

Does anyone else notice any movement even w/ the pins? If the pins don't lock the hood down 100%, then I think I'd just rather go back to the stock hood.

[spokismB5S4]

Does anyone else notice any movement even w/ the pins? If the pins don't lock the hood down 100%, then I think I'd just rather go back to the stock hood.

even if it moves about a bit, its not gonna go anywhere with pins.

[Sfarooq]

The hood doesn't "lift off" but you can see it move slightly at the corners. The center latch seems rather secure. But yeah, I'm either getting pins or going back to a stock hood.

I knew that you were merely referring to the hood flexing upward due to wind-pressure as speeds increase and used the vernacular "lift off" to represent the action; I was just saying that yes, it would be a good idea for you to get yourself some pins or just revert back to stock. Either case, your CF hood mounted using a stock hood-latch is a recipe for disaster.

[zakario]

I bought my S4 with the CF hood (and front fenders) so I'm not sure what brand it is - but it is unreinforced and it flops around a bit. Fit isn't great but I think that is due to how the pins were installed. It's super light though and that's all I care about since the car isn't my track car. I also like the vents to keep things cool.

So you would want heavy, but properly fitting body panels for your "track car". Makes tons of sense.

[onemoremile]

With the pins properly adjusted the hood is locked down very securely and doesn't move or get those speed wobbles at all. A huge part of the issue is the quality of the hoods. It takes more than $500 in materials to make a structural carbon hood and the Vis and even Vorsteiner just aren't made all that well. My Vorsteiner has a layer of carbon over a layer of hexcell. That hexcell reinforcement is not sandwiched between another layer of carbon which would increase the strength and rigidity tremendously. Carbon's strength comes from creating a sandwich layup that acts as an I or H beam and the way mine was done just doesn't close up the bottom of that beam.

One could be made with carbon over a few layers of basalt or knit bamboo (both are lighter, cheaper, and stronger than fiberglass) with another carbon layer on the bottom and it would be far more rigid than the current offerings. It would also keep it from cracking like my Vorsteiner. The hood latch should have aluminum, titanium, or stainless threaded inserts like you use in wood working. They would spread the load and if they were also held by a metal backing plate then pins would be completely irrelevant. Some fancy cars come stock with carbon hoods and they don't have pins because those hoods are strong and expensive.

Cheap, light, strong. <**- pick any two, you can't get all three.



To address the aluminum issue, I don't think one is available for these cars. My 01 allroad smacked a deer Friday morning and that aluminum hood is remarkably strong. It weighs almost as much as a steel one so I'll take the insurance check and buy a steel one with it. A half dozen pounds couldn't more irrelevant on a 4400 pound car.

As far as real performance gains go, you would be far better off with a battery relocation than with a carbon hood. The price is far more palatable as well.




This is the hood that jump started the sales of hood pins. Ouch.

[onemoremile]

I bought my S4 with the CF hood (and front fenders) so I'm not sure what brand it is - but it is unreinforced and it flops around a bit. Fit isn't great but I think that is due to how the pins were installed. It's super light though and that's all I care about since the car isn't my track car. I also like the vents to keep things cool.

It looks like the SDR hood.

[CruzS4]

Back in the day it happened to the AWE project car.

Really? That black avant with the LMs that they used to have in the showroom sometimes?