Carbon fibre lowered floor

[dand]

Is there such a thing? Or is the only option the aluminium version?

[SM25T]

There are a couple of all-carbon Caterham out there, but they were a special home build by a carbon supplier ... sadly no longer with us. Aluminium floor from Arch Motors is the way forward. They do offer to supply and fit while you wait.

[SLR No.77]

The lowered floor is bl**dy heavy though, definitely worth investigating a carbon alternative even if it's maybe part carbon within an aluminium outer frame. The lowered floor is substantially thicker/heavier than the standard floor.

Stu.

[elie boone]

It would be possible if you support the seat from the chassis rails as was the case in the 80's and to save weight one could make the runners part of the support.

[rj]

The floor adds to the stiffness of the chassis. Hence the lowered floor need to be significantly thicker than a flat panel. You could probably make a relatively rigid frame, a thinner panel and then, as Elie suggests fix the seats in the chassis like for older cars. But... I would not want a carbon floor to cut my legs in case of an accident - just like I don't fancy a carbon dash.

[SM25T]

Indeed .... aluminium is more friendly.

[SLR No.77]

Regin you are correct that the lowered floor needs to be substantially thicker to be stiff enough laterally, but beyond the shaped sides the main flat sections could be weight-reduced quite effectively by cutting out much of the sheet and replacing with thinner aluminium or carbon. IIRC they're 3mm sheet compared to 1.5mm for the standard floors.

Stu.

[rj]

Stu,

If the sheet you can reduce thichness of is 1.2x0.4m and you can reduce it by 1.5mm then the weight saving on the panel is around 400g, but there'll be an overlap, a lot of rivets and even the need for some brackets so at the end of the day you'll have a much more complicated design with not much gain

[SLR No.77]

Ah but Regin, this is the David Brailsford method of achieving better performance ... incremental gains 

Stu.

[rj]

Stu,

There are not many wieght saving options where I say "not worth it" but this is one of them.

(Mind you I've even gun-drilled my uper steering column and spent hours shortening the wiring loom).

 

[rj]

I would rather make a lower steering column from a thin aluminium tube filled with some kind of epoxy with micro-ballons and wound in carbon.

The reason for filling it is to prevent it from colapsing

[SLR No.77]

I've not actually weighed one, but I suspect just one lowered floor panel is heavier than a complete o/e steering column. There's a lot of metal that could easily be removed to save weight, taking a hole cutter to it would be a good start.

Stu.

[rj]

If I remember correctly the lower steering column weighed around 1400g; I know that I removed 297g from the upper.

[garybee]

Carbon would be a bad choice to make a floor out of (particularly on a 7) due to it's poor impact resistance.

[rj]

Exactly. I've had a bolt the car in front of me dropped on a trackday make a relatively deep dent in the passenger floor. Had it been carbon there'd have been no dent but a biiig hole.