Roll Bar question
 

It seems I might have misinterpreted the rule book on my roll bar instilation. I put in 1-5/8 .083-4130 with all the other bars the same except the X side bars are 1-1/2 .065. I ran bars from front frame to rear tied into the main hoop with provisions of later doing the front pillar down bars and halo. Just need to know from the experts if legal with that size bars, if not I'll just do the down bars. It seems silly the 1-5/8 4130 is ok for a cage but not a roll bar. Thank you, Mike

Re: Roll Bar question
 

I know of two examples of roll bars made from 1 5/8" tube , and both were changed to a roll cages to make them legal . A roll bar needs to be made from 1 3/4" tubing x .118" thick if Mild Steel , or .083" if 4130 chromoly tubing .

Re: Roll Bar question
 

You have the start of a cage , but not a legal roll bar .
Roll bar must be 1 3/4" .083 moly or 1 3/4"x .118 min mild steel.
the side door bars may be 1 1/2"x.065 moly ,IF it is done as an X , otherwise the 1 5/8 applies for the cage and 1 3/4 for the roll bar.

Re: Roll Bar question
 

It sounds like you are doing the install now, why not just go ahead and do a full cage? It will both future proof the car if you move up in classes and save you the pain of upgrading a roll bar with a finished headliner installed.

Re: Roll Bar question
 

Everyone is correct on your issue. Go out and buy some more moly and finish the cage.

Re: Roll Bar question
 

Thanks for replys, got a bunch of tubing for next car so no problem on that. Like the idea of full cage just didn't want the hassles of the net and yes still in the building stage. It'll be easy to do, just four bars a couple bends and time. Am I right, no cert till 9.99 et?
Also don't want to buy the 1-3/4 dies for just one roll bar either.

Re: Roll Bar question
 

The chassis needs a certification at 9.99 or quicker or if the speed is over 135 mph. I once had a NHRA tech guy question the mph record of the class, not my mph.

Re: Roll Bar question
 

You don't need a window net unless your class requires a roll cage , or you have a certified cage and you are running faster than 9.99 secs or 135 mph .

Re: Roll Bar question
 

IMO: If you have a cage, you are required to a have a window net. Also per Ihra rules, net must extend forward to within 2" of the farthest back portion of the steering wheel. Can't find NHRA ruling. Check a few cars for that one!

Re: Roll Bar question
 

Yeah, I wouldn't have written that without looking it up in the NHRA rulebook . You can check it out in Section 20, page 32 , under "6.3 Window Net" . It might be different for IHRA .