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The Problem

I'm looking to install a carbon fiber hood for appearance reasons. The manufacturer, as well as many websites, insist that hood pins are required in case of a failure of the hood latch. Unfortunately, I do not like the look of hood pins, to the point that I might actually rather not even have the CF hood if I need them.

5 out of the 6 people that I know with CF hoods do not use pins. Unfortunately, I can find no real statistics on how often a latch failure actually occurs to determine risk, so running without them would make me a little uncomfortable.

The Solution?

The obvious solution is some sort of non-destructive reinforcement; the obvious mechanism coming to mind being magnetic. A powerful magnet with a piece of soft rubbery material on the bottom could be easily attached to the top of the hood and be removed on demand, providing structural support while at highway speeds but enhanced (imo) appearance when at a car cruise or just parked in the garage. And it would only require a sheet of magnetic material attached invisibly to the bottom of the hood.

However, I can't seem to find anything like this for sale online; a google search just returns a large number of 'pretend' pins for appearance. I could probably design and make something myself. Although a little pricy, it's easy enough to find magnets that can lift over a hundred lbs and could crush the CF hood without effort, so I don't think there's any issue finding materials that will perform. But when a product is completely unavailable there's usually a reason.

So to my title question: why aren't magnetic hood pins used

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  • And how much lifting force can a hood generate? Any idea of ground effect forces? Seen any videos of hoods coming open on youtube?
    – Solar Mike
    Jun 9 at 13:10
  • I don't know the answers to those questions, which is why I'm asking before doing. :)
    – Nicholas
    Jun 9 at 14:04
  • If it's that easy to remove the magnet it's not going to do much good holding your hood closed.
    – GdD
    Jun 9 at 16:59
  • 1
    Just want to point out that switched magnets are a thing. They have a small toggle that turns the magnetic force on and off, but don't require electricity.
    – JPhi1618
    Jun 10 at 16:51
  • 1
    I suggest a black carbon fiber vinyl hood wrap.
    – chili555
    Jun 15 at 21:48
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In instances where the bonnet/hood latch has failed at highway speeds what generally happens is the bonnet is flipped up destroying itself, the windscreen, and completely obscuring the driver's view in the process. I think we can all agree that would be a Bad ThingTM right?

The amount of force from the aerodynamics at even moderate highway speeds is substantial so anything that you can remove by pulling with your hand like your magnetic idea is going to be about as much use as a chocolate fireguard. Worse - if the bonnet catch fails you're going to have a couple of extra little missiles being flung at your face. Anything magnetic you can't remove by hand is going to defeat the point and you won't be able to access the engine bay.

So why do CF bonnets/hoods need pins when OEM metal hoods don't? Two reasons - firstly the latch on CF bonnet is typically just fibreglass bonded/glued to the main part of it, this is never going to be as strong as something that is welded/riveted metal like the original.

So it's already weaker than the original, secondly CF bonnets are generally thinner, lighter and less stiff than their metal brethren which can often translate in to flexing under load (such as the aerodynamic loads at highway speeds), that flexing is working, pretty constantly to weaken the bonding between the latch and the main structure of the bonnet and when that's the only thing holding your bonnet in place at the front it's taking all that energy, which (as you've discovered from the manufacturer) it was never designed to do.

I'm not saying it's certainly going to fail - but it's definitely likely enough that the manufacturer considered it necessary to cover their ass if it did.

Bonnet pins aren't the most attractive thing in the world - but they aren't a recommendation for looks or for funsies, they're a safety thing.

If you can't get over the aesthetics of conventional bonnet pins have you looked into less obtrusive options like the AeroCatch Xtreme? They're more expensive than old-school pins but are flush to the bonnet and pretty damn strong to boot.

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