Uni body cage mounting

[curtklze]

Section 3.B roll cages: 

It's states on unitized construction car it must have 1/4 inch thick support pads on the top AND BOTTOM of the floor or sill.


Is this only for bolted in cages?

[Stainless1]

Are you thinking if you weld it to the sheetmetal it will be strong enough?  The idea behind the 1/4 inch pads is it gives you something to weld to and the big sandwich area will be harder to pull/push out...
Of course if you think there is enough structure there to weld to you can take lots of pictures, present engineering data and try to convince the tech chair that you have it covered....

[curtklze]

I just confused.  If I weld the tube to the approved plate and then weld the plate to the floor , how does welding the exact same sized  plate to the under side of the floor make it stronger? Wouldn't welding the same square on both sides  make the floor metal weaker due to the heating of the thin metal on both sides?   

[Stainless1]

OK, now we understand the question... you will be bolting in your cage to the floor if you don't have a frame to weld/mount it to.  Remember the pad sizes and bolt requirements are minimums and Bonneville cars tend to get heavier not lighter.... oh and it is your ass on the line here so build accordingly. 
Remember to build a cage that protects all 6 sides of the driver

[Stan Back]

. . . and weight is not necessarily a bad thing in a Bonneville-bound vehicle.

[Happy Pappy]

[quote author=Stan Back
. . . and weight is not necessarily a bad thing in a Bonneville-bound vehicle.


Amen to that!!

[curtklze]

This pic is off the Internet to use as an example  of what I was thinking. I'm going to have it mounted like this in all 4 corners....so firewalls side sills and floor.
http://tougefactory.com/shop/wp-content/uploads/2018/01/RAL_8264.jpg
But as per the rules I would need to add a plate under the floor and bolt the upper and bottom plates together. Just need to make sure so I pass tech.

[SteveM]

Unless the rules have changed recently, you do not need to weld AND bolt.  the 1/4" total thickness is for welded in cages.  The 1/4" plate sandwich (above and below) was for bolted-in cages.

Steve.