i have this cage
http://store.summitracing.com/partde...5&autoview=sku

question is for the 2 bars that come off the center hoop down to the driveshaft tunnel do i need the 6x6 plates? cant buy a nhra rulebook till next month and i only got 6 plates and it attachs to the car in 8 spots

 

Technically, they're supposed to attach to a subframe. If no subframe runs along the driveshaft tunnel, attach them to 6x6 plates. Your local steel supplier should be able to provide you with some 6 x 6 x 1/8 plates. One foot of 6 x 1/8 flat steel cut in half.

That's a roll bar not a roll cage. It's not a cage unless it has a halo bar and a-pillar bars.

 

Those bars aren't required for down to 10.0@ 135. They really only require a 5 point where you have 2 from main hoop, 2 rears, and driver door. Down to 8.50 takes the halo with a-pillar bars and those 2 going toward the tunnel from the main hoop.

 

well alot of the reason i want it is for frame stiffness, not to mention my driveshaft loop is welded right under where they are going to connect. Its made of 1"x3" rectangle tubing and my torque arm will mount to it. Since i have subframe connectors welded under where the main hoop will be connected and the door bars will be welded up front do i need the plates there? my connectors are welded the entire length of the floorboard and and pinchweld, made of 2' square tubing 1/8' think. (i might have went a little over board.*shrug*) im trying to tye everthing togeather as a system so each part works off the rest's strengths.

 

Every point that's attached to the floor needs the plates. There isn't enough strength just welding the tube to the sheetmetal floor. Using the plates gives 2 feet of weld to secure it to the sheet metal.

Technically, you don't need those 2 bars. A 5/6 point roll bar is still good down to 10.0 as long as the floor or firewall have not been modified. Modified as in moving the firewall back or making a removable section for transmission removal.