Basic specs on a NASCAR cup car roll cage

[hotrod]

I'm wondering if any one here has access to NASCAR Nextel Cup rules (not avail to the general public I understand) and could dig up the basic specs and key construction details, used in a cup car roll cage?

Tube diameter, wall thickness, and key features like kickout on the door bars etc.

I'm trying to research a design for a roll cage for a 200+ mph bonneville car and wanted to look at the NASCAR designs as a reference point.

From what I've been able to find, they only give out their rules packages to "serious competitors". After lots of searching it appear the special construction details like gusset design/locations or other special features they have learned are necessary to survive a 200+ mph crash, do not appear to be easily available on the web.

I've found a few pictures, and have a plastic car model to use as reference but that is not nearlly as authorative as a rule specification.

Larry

[beth]

The NHRA rules give a lot of detail regarding their requirements. A builder who can certify an NHRA chassis would be a good source also. Tumbling in the salt at 200 mph is lots different and has different requirements compared to hitting a cement wall at 200. I have seen over the years that cages refered to as "funny car type cages" hold up the best in multiple roll or endo situations. The body and engine can break away during multiple rolls at high speed and a complete chassis can even come apart. The salt is more forgiving than pavement but you are very prudent to be prepared. My opinion is a funny car type cage with an aluminum lining connected directly to the cage and inside the chassis cage is the safest. NHRA certified builders are located throughout the country. When your belts are so tight you want to cry, have a crew member pull them a bit tighter.

good luck

beth

[motormonkey]

Ive seen alot of funnycar styled chassis at Bonne. and El mirage. barring streamliners. For what its worth.

[CoMaxRacing]

I also would base your build on a drag car and not an oval track car. The pro-mods in IHRA are going much faster than the cup cars so I would say that is a better basis.

[hotrod]

Oh there is no doubt that some of the other cage designs work well and they are already included in my research. The SFI 25.x specs for example, are at least available to the general public for $35, as are the NHRA, SCCA and other popular racing organizations rules and recommendations for cage design.

There are some differences between the situation in a funnycar, rail or pro-mod and a NACSAR crash though that are worth consideration. NASCAR has been crashing cars at 200 mph for decades and have an order of magnitude more experience that the other organizations. The drag cars are generally lighter, and are frequently undergoing rapid deceleration from a parachute deployment when they have problems. By and large they do not take the same sort of tumbling multiple impacts you see when a car goes into the infield and hooks a wheel in the grass. That sort of incident results in the same sort of airborne tumbling impact that you see out on the salt. (IE the Eco tech incident)

I already have good pictures of the cage structures in several of the Bonneville cars.

The NASCAR cage info is simply a necessary data point for reference. I would be incompetent to ignore their crash safety experience (assuming I can get the basic info to compare their cage structures to the other common high speed designs)

Larry

[Cobra]

The NASCAR Cup roll cage is integrated into the specific chassis design for these cars. 2007 will see a new chassis design for cup cars to increase driver safety. Crush zones are a big part of a NASCAR chassis, and if a car lacks room for these, safety may be compromised. A HANS device should be required for all cars traveling 200 MPH!