Seat Back Braces?

Looks like we will be needing one for the non-FIA seats in our LeMons car - a few questions:

1. Does the brace need to be bolted to the seat?
2. What's the recommended size for the plate that sits behind the seat? I was thinking 1/8" thickness, 4" height, 10 - 12" length. Is this overkill?

Thanks, Iain

http://www.ioportracing.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=ASB&Category_Code=IH

A picture of one already made. I built one very similar to this for only a few dollars. Link below to an example. Just buy two of the correct size and weld them together, get some flat stock and tubing and you are done!

http://www.mcmaster.com/#shaft-collars/=6u1uhn.

In reply to jimbbski:

Thanks! I already have a pair of the McMaster Carr shaft collars, and the link answers my question about the size of the backing plate.

I've not seen a requirement that it be bolted to the seat itself.

I've been looking into this myself. The only thing I saw was to make sure it covers as much seat back area as within reason. Sounds like huge gray area to me. Basically, you want to spread the load as much as you can.