My friend and I are putting a roll cage in his car, and when I checked the NHRA regulations I couldnt find anything about clearances. Is there a certain height that the main hoop must be above the drivers helmet? Also, is there a minimum for how far forward the door bars extend? Do the 6x6 plates for the door bars need to be welded tight to the rocker sill, or can they be cheated in a little? Does the main hoop have to be perfectly vertical, or can it be angled back? I have built 2 cages before, but they never had to be inspected, so if anyone on here could give me some answers for NHRA specs, it would be greatly appreciated.

 

Sorry but how fast did you look ? I remember a specific pitcute where the driver is sitting in the car, and it shows the clearance height.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AH1078 &raquo;</TD></TR><TR><TD CLASS="quote"> Also, is there a minimum for how far forward the door bars extend? Do the 6x6 plates for the door bars need to be welded tight to the rocker sill, or can they be cheated in a little? </TD></TR></TABLE>

Even if you cheat a little and it passes inspection, remember the lable is good and all but is that going to protect you in the crash ?

 

Pages 215 and 216 in the 2007 rulebook have your answers.
Get the main hoop as close to vertical as possible, meet all other criteria and you will be fine.