Lightweight Strengthening!

[Guest mr2sensei]

Hello All,

 

I have not long purchased a 2006 lightweight off ebay which came with loads of bits and a 2.0 pinto.

 

As yet I am undecided what engine to put in as I just want some sunny weekends to go driving, do the odd trackday and maybe a sprint.

 

I have been reading about the chassis problems after someone told me that there had been probs with one that had gone for SVA and the DVLA said that it was not fit for its purpose. As mine is still at an early stage as far as the building of the body goes am I best just making some extra brakets and stiffening some of the angles front and rear, around the diff and also some extra in the cockpit area?

 

I have found a place local to me where I can get some sheet to make my brackets. I was thinking 3 or 4 mm.

 

Cheers Rob

[Guest Tim Norman]

No doubt GDC will be along soon to point you in the right direction

[Guest Ad_W2001]

For mine, i've used predominantly 50mm x 50mm x 3mm aluminium box section and right angle L section. I think i bought 5 metres of each, maybe 10 of the L section. Good for making small brackets, and the preformed bends should be stronger than bending sheet yourself, which induces strain into the material.

[Guest gdc]

hi rob

welcome to the forum , if you go to big lees web site through rhocar at the bottom of the first page are most of the photos of my mods , they have been used to pass at least 2 lightweights . however i had a phone call from a builder last night saying he had modified prety much as i had and had been refused sva . the examiner said that he wanted to see a full chassis built whithin the car before he would pass it . he also said 2 had passed but had been very highly modified , i can only asume my 2 , so what mods he had in mind i dont know , i thought these people talked to each other .

sorry to be on a bit of a downer but i fail to see how this desion can be taken .

i have offered to take my cars to this test station for examination and ask why the fail .

 

regards graham

[Guest mr2sensei]

For mine, i've used predominantly 50mm x 50mm x 3mm aluminium box section and right angle L section. I think i bought 5 metres of each, maybe 10 of the L section. Good for making small brackets, and the preformed bends should be stronger than bending sheet yourself, which induces strain into the material.

 

Thanks for the replys Guys!

 

Maybe I will find the local SVA test station and see what they have to say. Have no other Kitcar companys made a body in this way before? Coz I'm sure they have.

 

Maybe if I painted it yellow and put a wheel in each corner and wrote FOR HIRE on the side they would pass it......!

 

Rob

[Guest Nigel Novice]

Better off red with a prancing horse on the front, no bother then

 

I'm in the same boat as you having a lightweight already heavily modded but going to get more, rather than using the suggested folded pieces I will be using angle and box, going with a shopping list to local Alloy stockholder tomorrow

[Guest Wragie]

One thing that needs to be done to the kits is pretty simple and

that is flanging any holes. This is simply putting a lip around the

hole. You can use a tool or a hammer and block of wood.

 

This is one thing you need to try yourself because you will

not believe the difference it will make. A unflanged part

can be half as stiff/rigid as the flanged part. And it doesn't

add weight. Get a piece of paper cut a hole and hold it by

an edge, and of course it just flops over. Take the same

sheet and use your fingers to bend a small lip around

the hole. Now hold it by the edge, and it might bend a bit

but it will not fold over. The thing about this is that if

properly done you can make the hole bigger and be

stronger as the flange changes the stiffness.

 

Adding parts will fix somethings but can all concentrate

stress and then you get cracks and other fun.

 

Dave

(willing to bribe for build dvd's)

[Guest Nigel Novice]

Yes but some of the folded bits are thin flat pieces folded to create angle 1.6mm thick and I was thinking of changing this to 3mm extruded angle, one piece around the rear arch area if folded twice, once in half and then again to form 25x25x3 ish angle, again extruded is the way I'm going

[Guest Wragie]

Yes but some of the folded bits are thin flat pieces folded to create angle 1.6mm thick and I was thinking of changing this to 3mm extruded angle, one piece around the rear arch area if folded twice, once in half and then again to form 25x25x3 ish angle, again extruded is the way I'm going

 

When they are used like around the wheel arch they are just skin stiffeners. You don't need the added strength and weight of extrusions (angles) in these cases. We use a lot of bent sheet angle as skin stiffeners in aircraft and usually closer to 1mm thickness or less.

 

It isn't very well done from everything I've seen but that has more to do with the corners and the way the bent sheet angle is formed and cut. What the stock one ends up like is more or less 3 parts thinly attached. So they lose the strength and any real benefit at each bend. Extrusion would also weaken at these corners. What I would look at doing is making small angles to go across the cuts and pick up the rivets.

 

If the picture uploads and you can ignore the obviously professional graphics arts ;-] you can see the blue line across the corners. I would bend up another small sheet angle or use a thin extrusion and put this on the inside of the skin. It will be stiffer and lighter than your thick extrusion by quite a bit and you only have to drill and pop 4 rivets. The red lines are where you will see cracks form in the skin and angles over time if this area isn't stiff enough.

 

Dave

(will post naked pictures of the cat for build dvd's)