Rollcage bar question

[WHITE T]

Guys,

I am in the middle of doing a full cage in my car. I was looking at the NHRA book, but couldnt find info in this.

On the front bars, the bar that would connect the front bars (by the visors), does this need to be same material size or can it be smaller diameter? I am using 1 5/8 x .125 DOM. I would like to use 1 1/2 x .125 here.

I know the dash bar (is not needed) but if used can be smaller, but I did not see anything about the upper bar by the visor.

Thx!
Rick

 

[gnxtc2]

The halo, hoop, all down bars and swings out are the same size. The crossbar behind the seat is small diameter. My cage is all chromoly.

Billy T.
gnxtc2@aol.com

 

[TurboTerry87gn]

SFI 25.5 Specifies the upper windshield/Halo bar must be 1 5/8" 0.083 for C/M or 1-5/8" 0.118 for mild steel.

The Notes:
Vl.3 The primary roof structure (top of cage) may be formed by attaching the upper windshield/Halo Bar to the driver side windshield/roof bar and passenger side windshield/roof bar, or by forming the upper windshield/halo bar into a halo (extending rearward to the main hoop) supported by the driver side windshiel/roof bar and passenger side windshield/roof bar.

 

[WHITE T]

Thx guys! That is what I needed.

1 5/8's it is!

 

[Nick Micale]

Rick, you probably will need to gusset the windshield bar, or maybe you plan to do that already?

 

[WHITE T]

I didn't plan on it.. but it could be done!

I will be able to fully weld around all bars, so I didnt plan to gusset them.

Thx guys!!!