NASA rollcage requirements

[Guest Mberglo]

Perhaps someone can locate the SCCA, IHRA and other sanctioning bodies and put their requirements in this post, turn it into a FAQ, and keep it handy for those of us wanting to cage our Zs.

 

NASA's complete 2007 CCRs can be found here

 

The following is an exerpt from the CCR as it relates to rollcages to be used in competition. There are separate requirements for HPDE rollbars.

 

15.6 Roll Cage

15.6.1 Purpose

The basic purpose of the roll cage is to protect the occupant in case of a rollover or a

collision. It should be able to withstand the weight of the car landing on the roof. These

rules apply to all classes, unless otherwise superseded by the class rules. Vehicles

homologated by, or built to the specifications of, SCCA, IMSA, and Grand AM must

conform to these rules, or may conform to their respective current class rules for roll

cage requirements for guest groups and special events. Any vehicle that does not

conform to the NASA cage rules, yet conforms to cage rules of another recognized

sanctioning body (SCCA, IMSA, Grand Am, etc.), that wishes compete in NASA events

on a regular basis, should be ordered to make modifications within a time frame

specified by the Race Director and approved by the Regional Director. Note- It is the

responsibility of the driver to furnish a copy of any non-NASA rules applicable to his/her

vehicle.

15.6.2 Intent

Chassis stiffening is a side benefit of a good roll cage system, but it is not the intent of

these rules. Parts of the cage deemed by the Chief Scrutineer, to serve no practical

purpose other than chassis stiffening may be considered in violation of the intent of

these rules (Note: Some class rules allow for chassis stiffening.). The Chief Scrutineer

may order the removal of said parts, or require that the vehicle owner redesign,

reconstruct, and re-certify the roll cage if warranted. The removal or redesign of the

cage, whole or in part, to comply with these rules, does not imply that penalties will not

be issued for violating the intent of these rules.

15.6.3 Installation

The cage may be removable or may be permanently welded, or any combination

thereof, providing that all aspects of the cage meet these rules.

15.6.4 Padding

All roll cage surfaces that may come in contact with the driver should be padded with

high-density padding such as Ethafoam or Ensolite. It is recommended that padding

meeting SFI specification 45.1 be used.

15.6.5 Bends

None of the tubing may show any signs of crimping or wall failure. All bends must be

Mandrel type. The center radius of the bends may not be less than three (3) times the

outside diameter of the roll cage tubing.

15.6.6 Main Hoop

The main roll cage hoop should be as wide as the full width of the interior and must be

as close to the roof as possible without violating CCR section #15.6.20 Inspection. One

continuous length of roll bar tubing shall be used as the main hoop. The main hoop

must consist of not more than four (4) bends maximum, totaling one hundred eighty

(180) degrees +/- ten (10) degrees.

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15.6.7 Diagonal Brace

At least one (1) diagonal brace shall be used in the same plane as the main hoop. One

end of the diagonal brace shall attach to the corner, or horizontal part, of the main hoop

above the driver’s head, within twelve (12) inches of the driver’s-side corner. The other

end of the diagonal brace shall attach to the mounting plate (or to the main hoop as

close to the mounting plate as practically possible) diagonally opposed to the driver’s

head (passenger floor).

15.6.8 Forward Hoops (Option 1)

The forward hoops shall extend from the main hoop (in a forward direction) to the floor

by following the roof and the “A†pillar of the car. There shall be a bar connecting the

two (2) forward hoops at the top of the windshield mounted as close to the roof as

possible without violating CCR Section #15.6.20 Inspection. The forward hoops shall

incorporate no more than four bends each. Optionally a “15.6.9 Halo Hoop (Option 2)â€

or “15.6.10 Front Hoop (Option 3)†construction may also be acceptable.

15.6.9 Halo Hoop (Option 2)

A “halo bar†extends from the main hoop (in a forward direction) following the roof line to

the windshield then following along the top of the windshield, then following the roof line

back to the main hoop, thus creating a “halo†over the driver’s head. A “halo†bar shall

be constructed of one (1) continuous piece of tubing. One (1) down tube following the

“A†pillar must support the “halo†on each side of the car. The down tubes shall

incorporate no more than two (2) bends each.

15.6.10 Front Hoop (Option 3)

A “front hoop†is a bar that extends up from the floor, then follows the “A†pillar up to the

roof, then follows the roof line across the top of the windshield, then back down the other

“A†pillar, and then terminates on the floor. There must be one (1) horizontal bar

(following the roof line) connecting the main hoop and the forward hoop on each side of

the car. The front hoop shall incorporate no more than four (4) bends.

15.6.11 Rear Braces

The main hoop must have two (2) braces extending to the rear. The braces shall be

attached as near as possible to the top of the main hoop, and no more than six (6)

inches below the top. The braces must not contain any bends*. There must be at

least 30 degrees between the plane of the main hoop and the plane of the rear braces.

The main hoop rear braces shall be installed to form no more than a one hundred five

(105) degree angle or no less than a seventy-five (75) degree angle with the main hoop

when viewed from the top. The main hoop braces may be mounted at the rear shock

mounts or suspension pickup points (providing that the braces remain in compliance with

all other sections of the CCR). They may go through any rear bulkhead(s) provided the

bulkhead(s) is sealed around the cage braces. *There may be certain exceptions

allowed for cars that cannot possible meet this “no bend†requirement. One exception is

listed [Ref:(15.6.11.A)]. Other exceptions may be made (not guaranteed) if all of the

required bars meet the specifications for a vehicle in the next heavier weight

classification and the alternative design is submitted to the NASA National Office for

special allowance.

15.6.11.A Rear Braces - Exceptions

On cars where the rear window/bulkhead prohibits the installation of rear braces

(Porsche 914, Pontiac Fiero, etc.) the main hoop must be attached to the body by plates

welded to the cage and bolted to the stock shoulder harness mounting location. There

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must also be a diagonal bar connecting the top of the main hoop to the lower front

passenger side mounting point (“Petty barâ€). Some cars built for racing in other

recognized sanctioning bodies may be granted a waiver of this rule, however they must

show proof of compliance with the current published rules for their class.

15.6.12 Door Bars / Side Impact Protection

At least one (1) door bar on driver side and one (1) on the passenger side must be used.

At least two (2) door bars on the driver side and one (1) door bar on the passenger side

must be installed in all vehicles that obtain a new logbook after January 1st, 2007.

All vehicles, regardless of date of manufacture or date of logbook issuance will be

required to have at least two (2) door bars on the driver side and one (1) door bar on the

passenger side starting January 1st, 2011.

Unless superseded by class rules, modifications to any non-chassis structure (such as

door panels, inner door sheet metal, windows, door internals, etc.) may be made to

accommodate any allowed door bar configuration. However, removal of material and /

or modifications is limited to 1) the least amount to accommodate the door bar(s), and 2)

can serve no other function. Holes in the door jam (B-pillar) may be permitted to

accommodate door bars; however the structure should not be “notched†so as to weaken

it.

The driver’s door window glass, window operating mechanism, armrest, map pockets,

door panel, and inside door latch may be removed providing that is for the sole purpose

of installing “NASCAR†style door bars.* The stock side impact beam, if equipped, and

the outside door latch/lock mechanism shall not be removed or modified.

*This gutting of the door is only permitted on driver’s door and, if undertaken, the roll

cage must incorporate at least two (2) NASCAR style door bars that extend into the

door. Certain class rules may supersede this rule. “NASCAR Style†means to NASCAR

specification in regard to configuration. For example, the two required bars should be

parallel with respect to each other, and contain the appropriate vertical support tubes.

See NASCAR rules for more information.

15.6.13 Mounting Points

The roll cage shall be mounted to the floor of the car in six, seven, or eight points. The

cage shall not go through the firewall. The seventh and eighth points must attach to the

firewall or front fender wells. All cage attachment points must be mounted to plates.

Each required cage bar shall terminate on a plate with a 360 degree weld to the

mounting plate, except as specified in Section 15.6.14.B. There shall be only one (1)

mounting “point†per plate. This point is defined as where the “required tube†mounts.

All additional tubes mounted to that plate must be mounted as close to the required tube

as possible [Ref: (15.6.14.].

15.6.14 Mounting Plates

Each mounting plate shall be no greater than one hundred (100) square inches and no

greater than twelve (12) inches or less than two (2) inches on a side. Welded mounting

plates shall be at least 0.080-inch thick. Plates may extend onto vertical sections of the

structure. Any mounting plate may be multi-angled, but shall not exceed one hundred

(100) square inches total including vertical sections. Each mounting plate should have

an area of not less than nine (9) square inches.

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15.6.14.A Mounting Plates – Bolt-In Cage

The attaching points of a bolt-in cage to the body must use reinforcing plates to

sandwich the body. At least three (3) bolts are required for each bolt-in plate and the

plate must be at least 3/16 inch thick. All hardware must be SAE Grade 5 or better with

5/16†diameter minimum. All nuts must be held securely by a locking system such as

safety wire, lock washer, Ny-lox, or jam-nuts.

15.6.14.B Tube / Mounting Plate Specifications

Any number of tubes may attach to a plate so long as they are touching each other at

the plate. There may be a small gap between tubes to allow welding 360 degrees

around each tube. If there is no gap between the tubes, they must be welded around

the base as much as possible to form a single figure-eight weld, AND the tubes must be

welded to each other two (2) inches up from the base plate.

15.6.15 Welds

All welding must be of the highest quality with full penetration and shall conform to the

American Welding Society D1.1, 1994 Edition, Structural Welding Code, Chapter 10,

Tubular Structures and Standards for the material used. Arc welding should be used

whenever possible. It is strongly recommended that the welder inspect all welds using

Magnafluxâ„¢, x-ray, or other effective methods. All tubes must be welded 360-degrees

around the circumference of the tube.

15.6.16 Tube Structure Design / Body

Tubes may touch the body in any place (not to violate CCR section #15.6.20 Inspection),

but shall not be attached anywhere except as permitted by CCR Section #15.6.11.A

Rear Braces - Exceptions. No deformation of the interior body panels is permitted,

except that the horizontal part of the sheet metal (next to the driver’s and/or passenger’s

head) between the top of the “B†pillar and the top of the “A†pillar, may be pushed in to

accommodate the roll cage. The intent of this allowed deformation is strictly to allow for

more headroom for the driver and/or passenger.

15.6.17 Additional Reinforcement

Any number of additional reinforcing bars are permitted within the structure of the cage

provided that they are installed strictly for safety and do not violate CCR Section #15.6.2

Intent. This rule does not permit reinforcements in classes with spec cages.

All required bars must be made of the same material and meet with at least the minimum

specifications for size and thickness.

15.6.18 Roll Cage Tubing Sizes

For the purposes of determining roll bar tubing sizes, vehicle weight is as raced, but

without fuel and driver. Note: There is an allowance of minus 0.010 inches on all tubing

thicknesses. Minimum tubing size for the roll cage is:

Up to 1500 lbs.

1.375†x 0.095†Chrome-moly / Seamless mild steel (DOM)

1501 - 2200 lbs.

1.500†x 0.095†Chrome-moly / Seamless mild steel (DOM)

1.500†x 0.120†ERW* (No issuance of log books for cars with ERW cages 04/30/03)

*Note- Specifications listed for reference for inspection of grandfathered vehicles.

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2201 - 3000 lbs.

1.500†x 0.120†Chrome-moly / Seamless mild steel (DOM)

1.750†x 0.095†Chrome-moly / Seamless mild steel (DOM)

1.750†x 0.120†ERW* (No issuance of log books for cars with ERW cages 04/30/03)

*Note- Specifications listed for reference for inspection of grandfathered vehicles.

3001 - 4000 lbs.

1.750†x .120†Chrome-moly / Seamless mild steel (DOM)

No ERW allowed.

Over 4000 lbs.

2.000†x 0.120†Chrome-moly/Seamless mild steel (DOM)

No ERW allowed.

15.6.19 Bending Allowances

If the maximum number of bends permitted for any one bar is exceeded, all required

components shall be made from the tubing size listed for the next heavier category and

must be approved by a NASA race tech shop or scrutineer.

15.6.20 Inspection

A 3/16-inch inspection hole must be drilled in each of the required bars in a non-critical

area for the purpose of determining wall thickness. All welds, except those mounted to

plates on the floor, must be accessible for inspection (360 degrees).

15.6.21 Head Restraint

A head restraint must be used to help prevent whiplash. The head restraint should have

a minimum area of thirty-six (36) square inches and be padded with a non-resilient

material such as Ethafoam or Ensolite with a minimum thickness of one (1) inch. It is

recommended that padding meeting SFI specification 45.2 be used.

15.6.22 Seat Back Support

A seatback support must be made to hold the seat from going back in the event of a

crash. A plate should be used to distribute the load. No bolts, corners, or sharp objects

should be placed in such a manner that could lead to a possible puncture of the driver in

a high impact crash. Proper design and installation is crucial to safety and it is

recommended that the driver employ the services of a professional race car builder for

this, as well as all other vehicle safety items. An exception may be made for those

seats homologated to, and mounted in accordance, with FIA 8855-1999 standards.

Those seats that qualify for the aforementioned exception must conform to the entire FIA

8855-1999 set of regulations. This includes a mandatory seat replacement, or use of a

seat back brace, for any seat more than five (5) years old. Please reference the FIA

regulations. http://www.fia.com/

[JMortensen]

The rules change every year, but here is the page with SCCA's current rulebook:

http://www.scca.org/Club/Index.asp?IdS=125B8C-71641F0&x=030|057&~=

 

Anyone building a cage really should figure out what type of racing you're going to do FIRST. Many of the rules in the post above only apply to you if you're RACING with NASA (door to door). If you just want to do time trials or track days, then those rules don't necessarily apply. I'm sure they won't allow ANY cage on the track, but there won't be as many limits to the design of the cage if you're not trying to fit a given class.

 

Looking at the rulebook will give you good guidelines for proper cage building, but you might not need to follow them to a T if you're not competing in a given class. For instance, the IT class Z car allows a 6 point roll cage with no bars through the firewall. They do this to prevent competitors from strengthening the chassis and gaining an unfair advantage. A GT3 (I think they moved the Z to GT3 this year) Z car can have a full tube chassis. The weight requirements are also different. The engine requirements as well as the brake requirements again are different.

 

The point is pick what you're going to do first.

[Guest Mberglo]

Jon makes a good point. The NASA requirements above are the baseline rules. Each competitive class then has variations from the baseline. Our Zs would fit into Performance Touring, which will allow bars through the firewall, but will cost you points and may bump you up a class.

 

HPDE and Time Trials are not required to have a cage at all.