I have a Kirk roll bar and I was wondering do I still need the black metal brace behind the front seats?

 

RTFR--Read The Rulebook.

If the rules for the people you want to run with say "thou shalt", then put it in. If not, then you don't need it.

There is a lot of debate over the use of seat-back braces anyway (assuming you're talking about the metal part that actually goes to the back of the seat). I know people who will argue passionately about it being a good thing, and those who will argue with equal vehemence about it being a bad thing. I haven't studied it long enough to form a real opinion on my own about it, though.

--DD

 

As previously said, check the rule book esp. since many clubs will look at it differently depending upon the FIA certification & date.