CF rear subframe?

A1ex · Post by **A1ex** » Thu May 10, 2012 9:18 am

So,

I think this would be the ultimate in subframe weight saving, what are peoples views on it? Possible or not? Does anyone know the forces on it from the rear wheels?

Dino · Post by **Dino** » Thu May 10, 2012 9:31 am

I wouldnt buy this unless it had been through a full range of crash tests, load testing etc to whatever the current eu requirement is.

Plus making by hand would mean inconsitent and non uniform final products being produced.

Safety first for me. Nice idea though

Post by **lewd lude lover** » Thu May 10, 2012 9:37 am

the 2ws subframe is rather light already to be honest.

Slashdotdash · Post by **Slashdotdash** » Thu May 10, 2012 9:41 am

Mental if your gonna give a diy one a go but god loves a tryer!!

A1ex · Post by **A1ex** » Thu May 10, 2012 9:53 am

Oh don't worry it would be designed first, I wouldn't just stick some fibre in a mould and hope for the best

As I have picked up the standard 2ws from I would say it's around 10 - 15 kgs in standard trim.

I designed CF wing panels in uni so I know what would be required as I still have all my notes, it would be a case of figuring out the forces on the frame.

Thinking about it, I don't think there is actually that much done by the rear subframe. It's pretty much a mounting point for the rear control arms isn't it?

Post by **Merlin** » Thu May 10, 2012 9:54 am

Thats all it does.

nitin_s1 · Post by **nitin_s1** » Thu May 10, 2012 10:27 am

Post by **Ammo** » Thu May 10, 2012 10:32 am

I think body panels would be a better way to go, Doors, Bonnet, Sunroof, boot and Rear arches

mercutio · Post by **mercutio** » Thu May 10, 2012 10:36 am

yes just a mounting point but hitting a kerb or stone with a wheel could transmit force to it it would be trick but for everyday driving i wouldnt trust it
theres a reason formula one cars stay on tracks cf is strong in one direction by the time you built it up so it was strong enough to cope with our roads it would weigh more than the steel one would be easier to make it out of billet alli.

A1ex · Post by **A1ex** » Thu May 10, 2012 10:55 am

Your a little off the mark there Gary.

The only reason steel is used as an everyday constriction material is because its cheap and readily available. It's strength to weight ratio is pretty poor compared to more advanced stuff. Composites have always stronger than something made from a singel material and there is reems of evidence in the real world supporting this. Tyres, boats, tennis rackets, supercars, F1 cars. Also the F1 cars are designed to survive 200mph crashes which is significantly more force than clipping a curb.

When designing the wing panels for my dissertation I was using software that was used by NASA to design their shuttle wings which was co written and designed by my project leader.

Using this software, I proved that with the correct layer orientation and design a CF panel can be stronger than Titanium & Duralium (Duralium is an advanced titanium - aluminium alloy which is incredibly strong). If it's good enough for NASA...

If CF wasn't as 'safe' as steel, why have Maclaren build their MP4-12C around a CF safety cell.

I appreciate this has been designed and tested with hundered of millions of pounds of investment and I'm not claiming this will part, if I even make it, will be. It's a common misconception that composites aren't as good as metal.