Who thinks the MS3 needs a diet?

[nhluhr]

I don't feel the need to trumpet my resume on the internet. The facts stand for themselves. Building a part to be strong is not at all the same as building it to designed-in energy absorption specifications.

An intake trumpet is neither a structural part nor crash-related. I can tell you don't have a degree in materials engineering, as you wouldn't have asked for a tensile strength rating for "steel", "aluminum", or "carbon fiber". First of all, all those are very wide classes of engineering materials with strengths ranging from single-digit ksi to triple-digits based on alloying, heat treating, grain structure, and for carbon fiber, the size and orientation of the fiber itself as well as the matrix used in the composite.

Crash worthiness is a finely tuned science that takes far more than what any aftermarket company has the resources to accomplish. Crash survival in racecars is a hugely different topic than in street cars as the assumptions and requirements are massively different. The only similar thing is the concept of maintaining a survival space around the victim and absorbing energy at the periphery.

I'm not saying anybody should abandon the idea of getting one, just that they should be aware that an aftermarket hood is NOT going to be anywhere near the same in terms of crash-worthiness.

 

[F430TECH]

Actually I have a degree in Mechanical Engineering...and trust me thats not even close to the beginning of MY resume...

If I stand on a Carbon Fiber hood, its probably not going to dent or break, if I stand on a steel or aluminium one pretty sure it will dent or bend. Carbon IS stronger and ALWAYS better at dissipating energy end of story. Last time I checked auto makers want to make things for the cheapest possible price, pretty sure they dont go to any great lengths a far as examining grain structure, alloying or heat treating for something as insignificant as a hood. They find the cheapest possible method usually stamping, and use the cheapest possible material Steel. Sometimes Aluminum.

I never said the trumpet was a structural part, although it is connected to the engine and must withstand quite a lot of vibration. I was merely using it as an example of why carbon is stronger then steel or aluminium in a strength to thickness ratio. 3 layers in no particular orientation = 1.5mm thick and hugely strong. 1.5mm thick steel no matter whats its treatment will probably bend.

Crash worthiness is usually determined by the CRASH STRUCTURE. That is the spaceframe underneath the hood and fenders and everything else. Or did you forget usually the outside of the car is what the DESIGNERS come up with? Designers usually don't do much engineering, yes they may be restricted by the height of the bumper due to pedestrian safety measures and things such as that. But they don't determine crashworthiness. They make the shell. Its the engineers job to make the underneath crashworthy.

Thats the important part of an R8.

Thats where your crashworthiness comes from...they run the frame through FEA Stress Analysis long before any of the body parts...


Are we done now?

 

[nhluhr]

Actually I have a degree in Mechanical Engineering...

THEN YOU SHOULD UNDERSTAND:

If I stand on a Carbon Fiber hood, its probably not going to dent or break, if I stand on a steel or aluminium one pretty sure it will dent or bend.

that a hood on a roadgoing automobile is SUPPOSED to bend! They use very low carbon steels for a reason.

 

[F430TECH]

You just answered my argument for me. Why are they supposed to bend? To absorb energy and disspipate it during a crash?

What a better dissipator of energy? Carbon Composite or Steel?

That was my only argument...read over Frequent Flyers inital post, he claims they provide "NO impact absorption whatsoever". I was just letting him no that Carbon Fibre does in fact have better impact absorption than Aluminum or Steel. Most Carbon Hoods are copies of the factory OEM's as far as thickness and size. Therefore if they are made of pure Carbon or even composites they will in fact have better absorption impact resistance than Steel of the same thickness purely because of their nature. During the crash the energy is tranformed into shattering the composite instead of crumpling the metal.

Again if you don't think a company like Seibon or VIS hires some good engineers to make their Carbon stuff pretty damn stong maybe you should call them up.