Roll Cage Diameter

[DV19]

I've searched to no avail, so if someone can specifically point me in the right direction I'd appreciate it and also I'll remove this post if it's been discussed 100 times......

 

We're building a multipurpose car (1999/03 Mustang GT) that we'd like to run everywhere and we are at the point of having the roll cage built. So for 2005/04 what will/is the rule on roll-bar diameter and wall thickness? We deal a lot with European Manufacturers and their Cages there are much thinner I think than the NASCAR-ish rules are here. We've seen some rules that state: Roll cage tubing must be at a minimum of 1.25 inches OD tubing and no thinner than 0.098 wall mild steel or 1.25 x .083 Chromoly tubing. And we've seen rules that require much heavier stuff....

 

If we'd like to do some AIX stuff (down the road) and some other things, we need to build our cage so it will fit ALL rules, which means we'll have to go with the largest ruling no matter how overkill it may be.

 

Thanks for your help......

[DV19]

I found this in the NASA CCR page 60:

Minimum tubing size for the roll cage is:

2201 - 3000 lbs.

1.500” x 0.120” DOM/Alloy/Seamless

1.750” x 0.095” DOM/Alloy/Seamless

(No issuance of log books for cars with ERW cages being certified after April 30th, 2003)

 

Is/will this be the continued ruling? If so, why does a Chromolly bar have to be as thick as a DOM bar?

[mansier]

To clarify: The weights you have found are the car with no fuel, and no driver. Chromoly cages are approved on a case by case basis only, because of their relative complexity to weld (relative to DOM).

 

Get in touch with your region director and region technical director for more help on cage design and parameters.

 

LM

[mwilson7]

We were told that chromoly has to the same diameter because they can't tell the difference between chromoly and DOM once it's in the car and painted.

[Tom Beverly]

A little off subject, but in line with Marks comment:

 

How can they tell the differecnce between HREW, and DOM, once it is installed and painted?

[Frank Corkran]

ERW vs DOM, a bent paperclip through the required inspection hole will detect the seam inside the tube on ERW tube. The Drawing On Mandrel flattens this seam. Makes for one heck of a hard spot to get through with a cutoff saw, too.

[powerslide91]

So I have been talking to a cage builder in my area. His mainstay is NHRA cars. His prefered size tubing is 1 5/8 (095 wall I think) chromoly. Now that is not explicitly called out in the rules from what I have seen, but assuming the car stays under the 3000lb cap, it seems to me that it should be a legal option.

 

Any thoughts? Seems like a nice compermise to me, stronger than the minimun requirements but maybe a little lighter. Really, for me it would be an issue of not having to pay extra for him to special order tubing for my car.

[WhiskeyTango5.0]

DV19 posted the regs right out of the CCR earlier.

 

My understanding of it is, if you're running a 2201-3000lb car you'll need minimum 0.120 wall tubing for all the REQUIRED bars. You could however, run 0.095 (or even less) for non-required bars. Check the CCR's for details on what the "required" bars are.

 

By the way, unless your builder's giving you the 1 5/8" x 0.095 for free, you'll be paying for any tubing he uses anyway. Tubing's not cheap, but 1.5" x 0.120 is a pretty standard size and should be very close in cost to the tubing he normally uses. In fact, you could save some cash and buy 1.5" x 0.120 DOM instead of Chromoly, it's quite a bit cheaper... but that's a personal choice, don't want to get into the Chromoly vs. DOM debate.

 

Goodluck,

 

Ryan

[Guest]

So I have been talking to a cage builder in my area. His mainstay is NHRA cars. His prefered size tubing is 1 5/8 (095 wall I think) chromoly. Now that is not explicitly called out in the rules from what I have seen, but assuming the car stays under the 3000lb cap, it seems to me that it should be a legal option.

 

Any thoughts? Seems like a nice compermise to me, stronger than the minimun requirements but maybe a little lighter. Really, for me it would be an issue of not having to pay extra for him to special order tubing for my car.

 

1 5/8 x .095is not legal. you would need to run 1 5/8 x .120 to be legal

 

you can run 1 3/4 x .095. There is no wall thickness variations for ChroMoly.

 

also, are you sure that you want a cage designed and built by someone who's major experience comes from drag racing, they look at things a little differently than most road racers.

[Mean 69]

I don't have a rule book, hence the question. My guess is that my 69 Camaro will come in slightly higher than 3000 lbs, what changes in the reg's for the cage in this case? Can someone point a newbie to the NASA CCR's, I am interested in the "required" bar definition.

 

Mark

[Adam Ginsberg]

I don't have a rule book, hence the question. My guess is that my 69 Camaro will come in slightly higher than 3000 lbs, what changes in the reg's for the cage in this case? Can someone point a newbie to the NASA CCR's, I am interested in the "required" bar definition.

 

The 2004 NASA CCR's. Right click, save as.