Cage or Roll Bar Specs?

[907rs]

I'm starting to do research for my cage/rollbar, and can't find any NHRA or IHRA rule books online.

I don't want to speculate on what quarter mile times my car will run, But it'll be mini-tubbed and have all the DSE goodies, along with smallblock and twin turbos.

Anyone know what wall thickness and diameter/points are required for different quarter mile times?

[XcYZ]

Bill, this is an older article, but gives you an idea of the different levels and breakdowns. I know the NHRA dropped the 11.99 cutoff to 11.49.

http://www.hotrod.com/techarticles/48019/

[tndude]

Bill, this is an older article, but gives you an idea of the different levels and breakdowns. I know the NHRA dropped the 11.99 cutoff to 11.49.

http://www.hotrod.com/techarticles/48019/

Scott, where did you get your roll bars?

[907rs]

Thanks Scott. :thumbsup:

[907rs]

Scott, where did you get your roll bars?

Well Doug, since he just logged off, I'll answer it for him. He got his through DSE.

And speaking of DSE, one of our members is now a dealer for them! I'm sure he'll chime in when it's ready for publication.

[68protouring454]

whos the dealer, fess up?? camco? vince???
give it up
jake

[XcYZ]

Bill, this is the most technical info I could find. You will want to get a hold of a rulebook to be sure this is the most up to date. I know on Jan 1, 2005, the 11.99 break moved to 11.49.

ROLL BARS{reprint from IHRA Rulebook}
Mandatory in all cars running 11.49 or quicker, or per class
requirements. All roll bars must be within 6 inches of the rear or
side of the driver's head, extend in height at least 3 inches above
the driver's helmet with driver in normal driving position, and be at
least as wide as the driver's shoulders or within 1 inch of the
driver's door. Rollbar must be adequately supported or cross-braced
to prevent forward or lateral collapse. Rear braces must be
of the same diameter and wall thickness as the roll bar and
intersect with the roll bar at a point not more than 5 inches from
the top of the roll bar. Sidebar must be included on driver's side
and must pass the driver at a point midway between the shoulder
and elbow. Swing-out sidebar permitted. All roll bars must have in
their construction a cross bar for seat bracing and as the shoulder-
harness attachment point; cross bar must be installed no more
than 4 inches below, and not above, the driver's shoulders or to
side bar. All vehicles with OEM frame (i.e. pickup truck where body
bolts to framerails) must have roll bar welded or bolted to frame.
Installation of frame connectors on unibody cars does not
constitute a frame; therefore, it is not necessary to have the roll bar
attached to the frame. Unibody cars with stock floor and firewall
(wheeltubs permitted) may attach roll bar with 6-inch x 6-inch x
.125-inch steel plates on top and bottom of floor bolted together
with at least four 3/8-inch bolts and nuts, or weld main hoop to
rocker sill area with .125-inch reinforcing plates, with plates welded
completely. All 4130 chrome moly tube welding must be done by
approved TIG heliarc process; mild steel welding must be done by
approved MIG wire feed or approved TIG heliarc process. Welding
must be free of slag and porosity. Any grinding of welds prohibited.
Roll bar must be padded anywhere driver's helmet
may contact it while in driving position. Adequate padding must
have minimum 1/4-inch compression or meet SFI Spec 45.1.

ROLL CAGE{reprint}
Mandatory in all cars running quicker than 10.99 seconds or faster
than 135 mph, or per class requirements. Cars with unaltered
firewall, floor and body (from firewall rearward, wheeltubs
permitted) running between 10.00 and 10.99, roll bar permitted in
place of roll cage, or per Class Requirements. Cars with altered
firewall, floor faster than 11.49 must have rollcage and window net.
All cage structures must be designed in an attempt to protect the
driver from any angle, 360 degrees. All 4130 chrome-moly tube
welding must be done by approved TIG heliarc process; mild steel
tube welding must be approved MIG wire feed or TIG heliarc
process. Welding must be free of slag and porosity. Any grinding of
welds prohibited. Additionally, roll cage must be padded anywhere
the driver's helmet may contact it while in the driving position.
With driver in driving position, helmet must be in front of main
hoop. If helmet is behind or under main hoop, additional tubing,
same size and thickness as roll cage, must be added to protect
driver. Main hoop may be laid back or forward, but driver must be
encapsulated within the required roll cage components. On
unibody cars with stock floor and firewall (wheel tubs permitted),
the roll cage may be bolted or welded to the floor/rocker box via 6-
inch x 6-inch x .125-inch steel plates
Unless attaching to OEM floor or frame, the minimum requirements for a
frame member to which a roll cage member is attached are 1 5/8-
inch x .118-inch MS or .083-inch CM round and/or 2-inch x 2-inch
x .058 MS or CM rectangular.
All cage structures must have in their construction a cross bar for
seat bracing and as the shoulder-harness attachment point; cross
bar must be installed no more than 4 inches below, and not above,
the driver's shoulders, or to side bar. All required rear braces must
be installed at a minimum angle of 30 degrees from vertical and
must be welded in. Side bar must pass the driver at a point midway
between the shoulder and elbow.
Unless an OEM framerail is located below and outside of driver's
legs, a rocker or sill bar, minimum 1 5/8-inch x .083 CM or .118 MS
or 2-inch x 2-inch x .058-inch CM or MS rectangular, is mandatory
in any car with a modified floor or rocker box within the roll-cage
uprights (excluding 6 square feet of transmission maintenance
opening). Rocker bar must be installed below and outside of
driver's legs and must tie into the main hoop, the forward hoop,
frame, frame extension, or side diagonal. Rocker bar may not tie
into swing-out side bar support. If rocker bar ties into side diagonal
more than 5 inches (edge to edge) from forward roll-cage support
or main hoop, a 1 5/8-inch x .083 CM or .118 MS brace/gusset is
mandatory between the diagonal and forward roll-cage support or
main hoop.

[907rs]

Cool! Thanks again Scott; that's really in-depth, man. Yeah, I guess I'll have to fork over the ten bucks to get the book.

I don't plan on being a dragstrip junkie by any means, but I do plan on making a few passes and want it to be safe and legal.

[conekiller13]

Anyone know what Scca or Silver state Regs on cages are?

[sinned]

NASA requires at least 2"X.120" (at it's thinnest) so better go with at least 2"X.165" for the bends. You can go down to a 1.75"X.095 if you run cro-mo. Not worth it IMO. Silver state and SCCA are very similiar...way more stringent than NHRA or IHRA.

Of course hitting a guard rail at 120MPH is not really as bad as barrel rolling 6X at over 150MPH through the rocks and into a mountain side. Most of the SSCC wrecks I have seen you can't even tell what kind of car it might have been.

[conekiller13]

Denny,

Why do think Cro-Mo is not worth it? I had thought that was the standard..............I really don't know much when it comes to this though. :willy:

[sinned]

Added expense. The price of steel has tripled if not more in the last 3-5 months. Tubing has gotten VERY expensive. Using good old DOM 2X.150" will save a bunch of money without sacrificing much weight (maybe 40lbs or so if that).

The other reason is some organizations that spec cage constructions do not differentiate between cro-mo and DOM so using cro-mo might not have any weight advantage (the reason for use of cro-mo is usually you can run smaller tubing with the same protection for weight savings).

I have a friend who installed a very nice cage, passed tech at almost every sanctioning event EXCEPT the one he drove 800 miles to enter. They turned him around for floor plate size. I always recommend overbuilding the hell out of everything for that exact reason.

[67Sally]

Anyone know what Scca or Silver state Regs on cages are?

The 2005 Rule Book is at their site in pdf format "link" (http://www.silverstateclassicchallenge.com/rules-1-index.htm)
W.

[68protouring454]

i see for 2700 b vehicles and over they require 1.75x.090 wall
what would the reason for 2x.150 ?? those are scca rules right?, also nhra says 1 5/8 dom .118 minimum wall thickness in a bend, so you would need 1-5/8 .134 to make that, if you went 1.75x.090 it would not pass nhra, would 1.75 x .150 be the best bet to be good all the way around??

jake

[CraigMorrison]

On a mild steel roll cage we use 1.75"X .134". If SCCA allows mild steel (like NHRA/IHRA does) this might be the way to go.

[68protouring454]

what about scca?? i read thru rules posted above and over 2700lbs it needs 1.75 x1.50?? not sure i follow will your cage pass scca,silver state etc?
jake

[sinned]

Ahhh, and there lies the catch. That is why I recommended 2.00X.154". At that size you are only going to be gaining ~50lbs in extra weight and you are going to be guaranteed to pass any tech at any event..period.

[conekiller13]

Ahhh, and there lies the catch. That is why I recommended 2.00X.154". At that size you are only going to be gaining ~50lbs in extra weight and you are going to be guaranteed to pass any tech at any event..period.

Good point............