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Building a rollcage and seeking advice...

Discussion in 'The Hokey Ass Message Board' started by batt69nova, Jan 27, 2012.

  1. batt69nova
    Joined: Nov 4, 2009
    Posts: 225

    batt69nova
    Member
    from OR

    Title says it all...

    In the midst of replacing the floor, rockers...well, lets just say replacing everything along the bottom of the car, on my '54 olds Holiday.

    Decided to put in a cage. Figured that with the car braced up, the interior gutted, and the doors off for all the other metalwork that this is the best time to do it.

    I've never built a cage before. I searched on here and found a little info, but was wondering if anyone has built a cage in a tri five chevy or '54-'57 olds and has any pointers specific to my chassis. I realize the tri five chevs are somewhat different, but close enough for me to apply to the Olds.

    I'm looking on guidance for hoop placement (was planning on right where the b pillar would be if the car had them)-if there's a "sweet spot" for the main hoop? Also, good technique for anchoring the hoop/down tubes. I am currently planning on attaching downtubes to plates where the body mounts to the frame (beef up the body mount area). Should I go direct to the frame? If going to the frame, how does one isolate vibration or do you just not worry about it?

    Of course, all info will be appreciated!
     
  2. oj
    Joined: Jul 27, 2008
    Posts: 6,257

    oj
    Member

    I don't like doing a hoop/cage in a street-legal car, i feel they are more dangerous than safety related. To do it proper (per NHRA etc and most sanctioning bodies) the hoop has to go to the frame - not the body. I has to pass thru the floor and mounts to a pad welded to the frame. So you have a real problem about how to pass thru the floor to the frame. A unibody car is structurally sound so that you can weld to 1/8" (6X6) plates welded to the floor - but not so with a car that has a frame. As the car owner you can ignore the rules, not go to a track or not go fast enough to require a cage and weld it up as if it were a unibody. In that case i would get a prebent roll bar kit, they make them for the tri5 cheby. If you need a supplier shoot me a PM.
     
  3. batt69nova
    Joined: Nov 4, 2009
    Posts: 225

    batt69nova
    Member
    from OR

    While the car will retain street legality, it will see plenty of passes down the strip.

    I found this info:

    11.99
    By the time a car is capable of running between 11.00 and 11.99 seconds in the quarter-mile, safety requirements are especially important. Up until this point, factory seatbelts are acceptable, but in the 11-second-and-quicker time zone you need a quality safety harness. The minimum requirement is a 3-inch-wide, five-point harness meeting SFI spec 16.1. The 1995 National Hot Rod Association Rulebook outlines the proper way to mount the shoulder harness and belts.


    An NHRA-legal rollbar is also required in the category. Recent rule changes have reconfigured what NHRA classifies as a rollbar. The classic four-point bar is no longer acceptable. The new standard is mild-steel tubing of at least .120-inch wall thickness (most chassis companies, like Art Morrison, use .134-inch wall tubing) that includes a forward-running side bar from the main hoop past the driver’s shoulder. This bar is only required on the driver’s side, but most systems include both sides for a six-point rollbar.






    The car will be at least this fast at the track. So it seems that I need a cage if I want to run it at the strip.

    Also, the car is rather twisty, being a holiday...so I figure the cage will add some much needed stiffness. I am boxing some segments of the frame as well.

    I hope to actually run faster:

    10.99
    Cars running between 10.00 and 10.99 need all the above-mentioned safety equipment...

    A new NHRA safety rule change for 1995 states that cars running between 10.00 and 10.99 must have a rollcage unless the car has an unaltered firewall, floorpan and body (except for wheeltubs). This means if you have a street car with a stock floorpan and firewall but have tubbed it for bigger tires, all you need is a five-point rollbar until the car runs quicker than 10.00. Of course, a rollcage is perfectly acceptable if you wish to install one.




    EDIT,
    I should mention (in case I didn't) that the floor and firewall of this car are heavily modified, so, I don't see a way around the cage requirement.

    Thanks for the heads up regarding it having to go to the frame. I knew that was probably the best route to go, and will take that into account.

    What's a good way to seal the holes in the body? I've never seen "rollcage grommets"...
     
  4. finishline
    Joined: Nov 24, 2011
    Posts: 19

    finishline
    Member

    nhra rules is 11.50 and faster 5 point roll bar welded to the frame with a 5 point harness and 3.2/1 sfi jacket. as far as your firewall and floor goes i would have to see it. sounds like a cool build lets hear what engine,trans and rear you are running.
     

  5. Until I get to my other computer to send a few photos here is what I will tell you. In the N.H.R.A. world even if your car does not run fast enough to need a roll bar/cage and you install one it must meet spec's. It can not be made out of just anything and look cool. Do yourself a favor and get a 2012 N.H.R.A. rule book. Things change every year. Also It looks like your close to Portland. We have a grate N.H.R.A. inspector local that will help you when needed to clairfy questions. He's also the guy that will tell you Yes you can race or No you can't. Do it right the first time and you'll be a lot happier. To me it sounds like your taking an awful big bite all at once for possibly being new to racing. I've been at it a while now and still go to the book (a new one every year) as well as call Steve often.
    The Wizzard
     
  6. Until I get to my other computer to send a few photos here is what I will tell you. In the N.H.R.A. world even if your car does not run fast enough to need a roll bar/cage and you install one it must meet spec's. It can not be made out of just anything and look cool. Do yourself a favor and get a 2012 N.H.R.A. rule book. Things change every year. Also It looks like your close to Portland. We have a grate N.H.R.A. inspector local that will help you when needed to clairfy questions. He's also the guy that will tell you Yes you can race or No you can't. Do it right the first time and you'll be a lot happier. To me it sounds like your taking an awful big bite all at once for possibly being new to racing. I've been at it a while now and still go to the book (a new one every year) as well as call Steve often.
    The Wizzard
     
  7. Shaggy
    Joined: Mar 6, 2003
    Posts: 5,208

    Shaggy
    Member
    from Sultan, WA

    Umm, i dont see a traditionally built 57 olds running 10's so i really dont understand the reason....
     
  8. batt69nova
    Joined: Nov 4, 2009
    Posts: 225

    batt69nova
    Member
    from OR

    The current plan is to run a 394 Olds (already have one). The rearend is the stock 54 olds rear for now, but that might be replaced by a 9inch (easier to find parts for the 9).

    Trans is up in the air for now...I have an Olds auto (came with the 394), but am far more interested in running a manual.

    Rust issues mean reworking the lower firewall, and the floor from the firewall to the package tray. Somehow, the trunk is MINT....don't understand why the floor (no carpet on it) is gone, but the trunk is pristine...
     
  9. batt69nova
    Joined: Nov 4, 2009
    Posts: 225

    batt69nova
    Member
    from OR

    Thanks for the advice.

    I've never scratch built a cage before, just worked from kits that I know are already NHRA approved. To my knowlege, nobody offers premade anything for the olds (although, a tri-five chev cage may work??)

    I plan on building this one per the current regs, just thought I'd ask fellow HAMB members for general pointers. I'm doing the cage now, because I have the interior completely gutted, and figure that now is the best time to do so.

    It would be great to have a local (I am in PDX) resource to make sure the car complies with rules or give clarity for items in the rule book.
     
    Last edited: Jan 30, 2012
  10. 6-71
    Joined: Sep 15, 2005
    Posts: 542

    6-71
    Member

    I know this isn't the advice you are looking for,but I know from personal experience that some insurance companies will not insure a caged car for street driving.You might want to check with your insurer. Also from personal experience,after I caged my(ot) chopped pro-street S-10 truck I never felt comfortable with my head inches away from all that steel tubing. even a minor fender bender could be disasterous for you.
     


  11. Are you able to do your own bends in your shop or will you need help?
     

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