I plan to take this on for myself. Alright here's my question(s) what size pipe/tubing should be used when making a roll cage? I was considering 1.5" tubing. Mind you its only going to bea 6 point cage. Connecting at the rear shock towers, front up by the "Dead" pedal and lastly behind the seats. I've made measurements of hte main hoop being 114.5" long, the main hoop-to-shock towers being somewhere around 28", the main hoop to "dead" pedals being 58" and finally the cross bar being 52 7/8". This is for a CRX. If someone could give me measurements of an existing roll cage for my 90 CRX, just as a reference I would greatly appreciate it.
Building Roll Cage
- Thread starter brian1
- Start date
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brian11to1
Senior Member
Thanks B got my password fixed...
I just want it to get rid fo the annoying seat belts ion the doors and to stiffen the body. Mainly AutoX
brian11to1
Senior Member
So no one can tell me the size to use without me getting the book? Ok, thanks.
brian11to1
Senior Member
About how much will 28' (feet) of that cost me?
i believe most cages are built with 1 and 5/8's with a thickness between .06 and .09 but i have no idea on the rules...
what type of pipe do you plan to use and how do you plan to bend it?
i am in the process of doing a roll cage as well... i tried 2" exhaust tubing to try and get a rough fit but my bender kinked the shit out of the tubing on anything more than a 30 degree bend or so maybe a 45...
my next step would be some inch and 5/8's steel tubing, but just need to get time to go to the place to get it...
search for honda roll cages on google to get the exact type of tubing they use...
what type of pipe do you plan to use and how do you plan to bend it?
i am in the process of doing a roll cage as well... i tried 2" exhaust tubing to try and get a rough fit but my bender kinked the shit out of the tubing on anything more than a 30 degree bend or so maybe a 45...
my next step would be some inch and 5/8's steel tubing, but just need to get time to go to the place to get it...
search for honda roll cages on google to get the exact type of tubing they use...
I usually use 1 1/2" ID electrical conduit (1 3/4' OD)... rigid or emt depending on the application (i've built 3 cages/bars to date). You will need to use a mandrel bender to make the bends and you can rent those from an electrical wholesaler for about $40 per day (ask for a hydrolic conduit bender). If you are looking to add rigidity to the chasis, I suggest going with an 8-10 point cage made out of emt conduit (thiner and lighter)... 2 mounts on the floor behind the front seats, 2 mounts on the factory cross brace (just use their bolt holes) 2 mounts by the rear shock towers and the 2 seatbelt mounts for the driver and passenger = 8... for 10 points add 2 forward support bars mounted to the main hoop at 18" from the floor and attaching to the floorboards just foreward of the front seats
I've generally just used a modified version of the autopower roll bars but changing/adding mounting points as I see fit... make sure you weld around the joints completely and add a harness bar since you will probably end up loosing use of your stock seatbelts... the headrest restraint is also useful on a regular safety cage but not necessary on a reinforcement cage... diagonal bars are a plus
do a google search for "honda roll bars" for design ideas and if it is a bolt in cage, make sure to put a plate under the car to sandwitch the body since the body material is so thin...
autopower: http://www.autopowerindustries.com/Roll_Bars.htm
cost:
1 1/2 inch emt conduit : $1 per foot sold in 10 foot sections
4 inch widesheet metal : $ Free from a sheet metal shop (in the scrap
bins... use for mounting plates)
conduit bender : $40
wire and gas for welder : free from work but probably around $25
LOTS of time
Note: in order to get the bends correct for the main hoop, buy a section of cheap flexable copper pipe and bend that first into the shape you want for one side of the car, then copy it for the other side and you have a semetrical (sp?) main hoop that properly fits the contours of you car
have fun
I've generally just used a modified version of the autopower roll bars but changing/adding mounting points as I see fit... make sure you weld around the joints completely and add a harness bar since you will probably end up loosing use of your stock seatbelts... the headrest restraint is also useful on a regular safety cage but not necessary on a reinforcement cage... diagonal bars are a plus
do a google search for "honda roll bars" for design ideas and if it is a bolt in cage, make sure to put a plate under the car to sandwitch the body since the body material is so thin...
autopower: http://www.autopowerindustries.com/Roll_Bars.htm
cost:
1 1/2 inch emt conduit : $1 per foot sold in 10 foot sections
4 inch widesheet metal : $ Free from a sheet metal shop (in the scrap
bins... use for mounting plates)
conduit bender : $40
wire and gas for welder : free from work but probably around $25
LOTS of time
Note: in order to get the bends correct for the main hoop, buy a section of cheap flexable copper pipe and bend that first into the shape you want for one side of the car, then copy it for the other side and you have a semetrical (sp?) main hoop that properly fits the contours of you car
have fun
All open cars should have a roll bar installed to protect the occupant(s) from injury
during a roll-over. The roll bar should be able to withstand the compressional forces
involved in supporting the full weight of the car. The roll bar’s main hoop should extend
the full width of the car (except certain cars that have been approved by NASA). The
main hoop shall be one continuous piece with smooth bends and no evidence of
crimping or wall failure shall be present (i.e. should be Mandrel bends). All welds shall
be of the highest possible quality, with full penetration [Ref15.5.15)]. All mounting and
installation procedures should conform to those standards listed in the CCR section #0
regarding roll cages. ALL CARS with roll bars are required to have adequate roll bar
padding per CCR section #15.5.4 and also conform to section #15.5.22 pertaining to
seat back braces. The material and minimums are as follows: (All cars with full roll
cages shall conform to the applicable sections found in section #15.0.)
Vehicle weight Mild steel Alloy steel
Under 1500 lbs. 1.50" x .120" 1.375" x .095"
1501 - 2500 lbs. 1.75" x .120" 1.625" x .095"
Over 2500 lbs. 2.25" x .120" 2.000" x .095"
60
15.5.1 Purpose
The basic purpose of the roll cage is to protect the occupant in case of a rollover or a
collision. It must 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. Cars
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. It is the responsibility of the driver to have these (non-NASA) rules
in his/her possession.
15.5.2 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.
15.5.3 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.
15.5.4 Padding
All roll cage surfaces that may come in contact with the driver shall be padded with
high-density padding such as Ethafoam or Ensolite. It is recommended that padding
meeting SFI specification 45.1 be used.
15.5.5 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.
15.5.6 Main Hoop
The main roll cage hoop shall be as wide as the full width of the interior and must be as
close to the roof as possible without violating CCR section #15.5.2 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.
15.5.7 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
61
close to the mounting plate as practically possible) diagonally opposed to the driver’s
head (passenger floor).
15.5.8 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 #15.5.20 Inspection. The forward hoops shall
incorporate no more than four bends each. Optionally a “15.5.9 Halo Hoop (Option 2)â€
or “15.5.10 Front Hoop (Option 3)†construction may also be acceptable.
15.5.9 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 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.
15.5.10 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.
15.5.11 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 (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 bulkheads provided
the bulkhead is sealed around the cage braces.
15.5.11.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 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.
15.5.12 Door Bars / Side Impact Protection
At least one (1) door bar on driver side and one (1) on the passenger side must be
used. 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
62
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.
15.5.13 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 15.5.14.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: (15.5.14.B)].
15.5.14 Mounting Plates
Each mounting plate shall be no greater than 100 square inches and no greater than
12 inches or less than 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 100 square inches total
including vertical sections. Each mounting plate should have an area of not less than
nine (9) square inches.
15.5.14.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.
15.5.14.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.
15.5.15 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.
15.5.16 Tube Structure Design / Body
63
Tubes may touch the body in any place (not to violate CCR section #15.5.2 Inspection),
but shall not be attached anywhere except as permitted by CCR Section #15.5.11.A
Rear Braces - Exceptions. No deformation of the interior body panels is permitted,
except that the horizontal part of the sheet metal between the main hoop and the top of
the “A†pillar (next to the driver’s and/or passenger’s head), 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.
15.5.17 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
#15.5.2 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.
15.5.18 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†DOM/Alloy/Seamless
1501 - 2200 lbs.
1.500†x 0.095†DOM/Alloy/Seamless
(No issuance of log books for cars with ERW cages being certified after April 30th,
2003)
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)
3001 - 4000 lbs.
1.750†x .120†DOM/Alloy/Seamless.
No ERW allowed.
Over 4000 lbs.
2.000†x 0.120†DOM/Alloy/Seamless.
No ERW allowed.
15.5.19 Bending Allowances
If the maximum number of bends is exceeded all components shall be made from the
tubing size listed for the next heavier category and must be approved by a NASA race
tech station or scrutineer.
15.5.20 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).
15.5.21 Head Restraint
A head restraint must be used to help prevent whiplash. The head restraint shall 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 45.1 be used.
15.5.22 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 is 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
recommend 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 of any
seat more than five (5) years old. Please reference the FIA regulations.
http://www.fia.com
during a roll-over. The roll bar should be able to withstand the compressional forces
involved in supporting the full weight of the car. The roll bar’s main hoop should extend
the full width of the car (except certain cars that have been approved by NASA). The
main hoop shall be one continuous piece with smooth bends and no evidence of
crimping or wall failure shall be present (i.e. should be Mandrel bends). All welds shall
be of the highest possible quality, with full penetration [Ref
15.5.15)]. All mounting andinstallation procedures should conform to those standards listed in the CCR section #0
regarding roll cages. ALL CARS with roll bars are required to have adequate roll bar
padding per CCR section #15.5.4 and also conform to section #15.5.22 pertaining to
seat back braces. The material and minimums are as follows: (All cars with full roll
cages shall conform to the applicable sections found in section #15.0.)
Vehicle weight Mild steel Alloy steel
Under 1500 lbs. 1.50" x .120" 1.375" x .095"
1501 - 2500 lbs. 1.75" x .120" 1.625" x .095"
Over 2500 lbs. 2.25" x .120" 2.000" x .095"
60
15.5.1 Purpose
The basic purpose of the roll cage is to protect the occupant in case of a rollover or a
collision. It must 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. Cars
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. It is the responsibility of the driver to have these (non-NASA) rules
in his/her possession.
15.5.2 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.
15.5.3 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.
15.5.4 Padding
All roll cage surfaces that may come in contact with the driver shall be padded with
high-density padding such as Ethafoam or Ensolite. It is recommended that padding
meeting SFI specification 45.1 be used.
15.5.5 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.
15.5.6 Main Hoop
The main roll cage hoop shall be as wide as the full width of the interior and must be as
close to the roof as possible without violating CCR section #15.5.2 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.
15.5.7 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
61
close to the mounting plate as practically possible) diagonally opposed to the driver’s
head (passenger floor).
15.5.8 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 #15.5.20 Inspection. The forward hoops shall
incorporate no more than four bends each. Optionally a “15.5.9 Halo Hoop (Option 2)â€
or “15.5.10 Front Hoop (Option 3)†construction may also be acceptable.
15.5.9 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 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.
15.5.10 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.
15.5.11 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 (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 bulkheads provided
the bulkhead is sealed around the cage braces.
15.5.11.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 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.
15.5.12 Door Bars / Side Impact Protection
At least one (1) door bar on driver side and one (1) on the passenger side must be
used. 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
62
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.
15.5.13 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 15.5.14.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: (15.5.14.B)].
15.5.14 Mounting Plates
Each mounting plate shall be no greater than 100 square inches and no greater than
12 inches or less than 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 100 square inches total
including vertical sections. Each mounting plate should have an area of not less than
nine (9) square inches.
15.5.14.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.
15.5.14.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.
15.5.15 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.
15.5.16 Tube Structure Design / Body
63
Tubes may touch the body in any place (not to violate CCR section #15.5.2 Inspection),
but shall not be attached anywhere except as permitted by CCR Section #15.5.11.A
Rear Braces - Exceptions. No deformation of the interior body panels is permitted,
except that the horizontal part of the sheet metal between the main hoop and the top of
the “A†pillar (next to the driver’s and/or passenger’s head), 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.
15.5.17 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
#15.5.2 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.
15.5.18 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†DOM/Alloy/Seamless
1501 - 2200 lbs.
1.500†x 0.095†DOM/Alloy/Seamless
(No issuance of log books for cars with ERW cages being certified after April 30th,
2003)
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)
3001 - 4000 lbs.
1.750†x .120†DOM/Alloy/Seamless.
No ERW allowed.
Over 4000 lbs.
2.000†x 0.120†DOM/Alloy/Seamless.
No ERW allowed.
15.5.19 Bending Allowances
If the maximum number of bends is exceeded all components shall be made from the
tubing size listed for the next heavier category and must be approved by a NASA race
tech station or scrutineer.
15.5.20 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).
15.5.21 Head Restraint
A head restraint must be used to help prevent whiplash. The head restraint shall 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 45.1 be used.
15.5.22 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 is 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
recommend 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 of any
seat more than five (5) years old. Please reference the FIA regulations.
http://www.fia.com
Originally posted by Sed8ed@May 12 2004, 01:32 AM
I usually use 1 1/2" ID electrical conduit (1 3/4' OD)... rigid or emt depending on the application (i've built 3 cages/bars to date). You will need to use a mandrel bender to make the bends and you can rent those from an electrical wholesaler for about $40 per day (ask for a hydrolic conduit bender). If you are looking to add rigidity to the chasis, I suggest going with an 8-10 point cage made out of emt conduit (thiner and lighter)... 2 mounts on the floor behind the front seats, 2 mounts on the factory cross brace (just use their bolt holes) 2 mounts by the rear shock towers and the 2 seatbelt mounts for the driver and passenger = 8... for 10 points add 2 forward support bars mounted to the main hoop at 18" from the floor and attaching to the floorboards just foreward of the front seats
I've generally just used a modified version of the autopower roll bars but changing/adding mounting points as I see fit... make sure you weld around the joints completely and add a harness bar since you will probably end up loosing use of your stock seatbelts... the headrest restraint is also useful on a regular safety cage but not necessary on a reinforcement cage... diagonal bars are a plus
do a google search for "honda roll bars" for design ideas and if it is a bolt in cage, make sure to put a plate under the car to sandwitch the body since the body material is so thin...
autopower: http://www.autopowerindustries.com/Roll_Bars.htm
cost:
1 1/2 inch emt conduit : $1 per foot sold in 10 foot sections
4 inch widesheet metal : $ Free from a sheet metal shop (in the scrap
bins... use for mounting plates)
conduit bender : $40
wire and gas for welder : free from work but probably around $25
LOTS of time
Note: in order to get the bends correct for the main hoop, buy a section of cheap flexable copper pipe and bend that first into the shape you want for one side of the car, then copy it for the other side and you have a semetrical (sp?) main hoop that properly fits the contours of you car
have fun
Is this some kind of joke? Electrical conduit is made to shield and protect WIRE not to hold a car roof up when it is upside down! Please, use some good stuff for cages, at the very least ERW(with the appropriate wall thickness) steel and at the higher end some Cro-Moly. Please say this was some joke
Id love to see how a harness bar made out of conduit holds up in a frontal impact :unsure:brian11to1
Senior Member
STOP REPLYIN TO THIS POST. IM JUST GOING TO HAVE A SHOP NEAR ME MAKE A DAMN CAGE.
brian11to1
Senior Member
There's no reason to keep the thread going once I've completely changed my mind, now is there?
well, hate to break it to you, but you are not the only one who reads these threads.
now that we have that settled, i would rather have things cleared up as to what types of materials can and cannot be used. this way when someone happens to search and find this thread, they don't think "oh wow, i could just use some conduit and build a cage!".
get it??
now that we have that settled, i would rather have things cleared up as to what types of materials can and cannot be used. this way when someone happens to search and find this thread, they don't think "oh wow, i could just use some conduit and build a cage!".
get it??
Sorry, I should have explained myself more clearly... I wrote that too late at night. Firstly, I would not use regular couduit for a STRUCTURAL cage in the first place (at least not EMT) rather for a chasis stiffening aid. Secondly, the copper pipe is only used to get the measurements for the main hoop to later be copied onto the proper material.
Rigid conduit is a different all together, it is mild steel with a wall thickness of .139 inches, the requirement is .120 inches.
If you re-read my post, I did not say to use regular conduit for a safety cage rather I suggested against it. The two cages I have built have been for sanctioned autocross events and they were built strictly to stiffen the chasis...NOT to protect in a frontal impact or rollover... both passed inspection because they were not made to protect the driver rather to aid in vehicle control (and yes they were drilled)...
My mistake, I thought this was the purpose of this post
Rigid conduit is a different all together, it is mild steel with a wall thickness of .139 inches, the requirement is .120 inches.
If you re-read my post, I did not say to use regular conduit for a safety cage rather I suggested against it. The two cages I have built have been for sanctioned autocross events and they were built strictly to stiffen the chasis...NOT to protect in a frontal impact or rollover... both passed inspection because they were not made to protect the driver rather to aid in vehicle control (and yes they were drilled)...
My mistake, I thought this was the purpose of this post