How big should my spreader plates be??

[StuOwen86]

Just wondering how big my spreader plates should be that go under the legs of my rear roll cage? As big as poss to spread as much load as possible? I'm not using box section as the cage fits upto the roof as it is so was going to make up some plates in work from what steel plate we have lying about (not sure what thickness but we use upto 1" thick lol so have a varied selection) maybe some stainless for under the car and in the rear arches where they will be exposed to the elements.

 

[bloke]

don't hold me to this but something like 12cm square, 3mm thick, welded and at least 8.8 bolts, i've always used 12.1 though.

 

[Cupman29]

Plates have to be 120cm2 and at least 3mm thick.

Bolts have to be M8 grade 8.8 or above.

 

[StuOwen86]

That's good I can get some knocked up in work and get the cage fitted on the weekend does it make any difference if I go thicker than the 3mm? I know the body work isn't that thick so not sure if it's worth the extra thickness.

Quick one also will they fit under the car (near the sills for the front legs) with them that big and in the rear arches.

 

[mark123]

They normally go in the car.
IIRC the backstays only need to be 60cm2 (but you'd have to check the blue book to be sure).
If you go thicker than 3mm it is just more difficult to weld to the shell as it is not that thick.

 

[StuOwen86]

Yeah I have a set for inside the car which if I have time before my first track day will be welded in, I was just gonna put a set under the car also for extra strength mainly on the rear of the arches in case of a head on and the force pulling on the harnesses.

Thanks for the info anyway guys once again appreciate it.

 

[boorek]

Hi! Recently I put bolt in roll cage to my clio, but now I realized that I also need spreader plates... I don't think it will be issue if they will be welded on the outside, as cage is already in place... Also how you following shape of rear arches? Can people post more pics of their spreader plates? I'm also wondering if roll cage leg must be in center of spreader plate?

 

[bloke]

Welded on the inside. Depends on your cage if you can get the plates mounted centrally but as the name suggests it's about spreading the weight.

You'd probably be fine with them on the outside but me personally if it wasn't inside and out I'd have them on inside.

Is it for regs or just track days?

 

[boorek]

Just track days, I'm not too sure if I've got spare 3mm inside.... Plus welding outside will be so much easier. App J in Blue book says it can be done both ways if I remember correct. What shape of plates are people getting? Flat ones? L shape? Custom made? Worst bit will be rear arches I think.... As 3mm steel sheet wont go with curves easy

 

[bloke]

Fwir inside and out is for weld in? I Could be wrong though.

 

[boorek]

I'm not quite sure, but that looks like spreader plate is mounted outside (13) and inside (13a)

 

[loggyboy]

Its there to reinforce the shell where the impact/force is loaded, so inside or outside is fine.
But if its just for TDs then don't be too worried, just be sure it's well fixed for your own reassurance.