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NHRA Rules Governing Rollbars...

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,236
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Hermosa Beach, CA
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1987 Z51 Silver Coupe
NHRA Rules governing rollbars...

I was asked a question regarding rollbars and the NHRA's rules for convertibles. I decided to respond here so that many may share the inquiry asked of me.

In the stock classes, the rules state:
ROLL BARS

  • Mandatory in A/S through M/S*, A/SA through M/SA*, and all convertibles. Front braces may not extend in front of the firewall. Six-point attachments permitted. Roll cages permitted. See General Regulations 4:10, 4:11.

GR 4:10 ROLL BARS
  • 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 the 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 must have roll bar welded or bolted to the 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 chromoly tube welding must be done by approved TIG heliarc process; mild steel welding must be done by approved MIG wire feed or TIG heliarc process. Welding must be free of slag and porosity. Any grinding of welds prohibited. (see illustration in book) 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.
GR 4:11 ROLL CAGE
  • All cage structures must be designed in an attempt to protect the driver from any angle, 360 degrees. All 4130 chromoly tube welding must be done by approved TIG heliarc process; mild steel welding must be done by approved MIG wire feed or TIG heliarc process. Welding must be free of slag and porosity. Any grinding of welds prohibited. Plating of chassis prohibited in Comp for cars manufactured after 01-01-2002; painting permitted. Additionally, roll cage must be padded anywhere driver's helmet may contact it while in driving position. Advanced ET, Comp, Top Alcohol Dragster, Top Alcohol Funny Car, Pro Stock, Funny Cart and Top Fuel padding must meet SFI Spec 45.1. (see illustrations on pages 210-215).

I hope that helps you some Jerry. ;)

And I hope all drag racers may have received some benefit from this. :upthumbs
 
G

gfbrown

Guest
Ken - many thanks for posting this information. You ALWAYS come up with the GOOD (accurate) info that drivers need!

Brother Gary
 

-=Jeff=-

Well-known member
Joined
Feb 2, 2001
Messages
909
Location
Bartlett, IL. (Chicago Suburb)
Corvette
1990 ZR-1
So what happens when you want a roll bar and your helmet hits the roof when you are int he car? it states 3" above the drivers helmet.. in my car, if I cage it, that ain't gonna happen..
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,236
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
Ya know Jeff, the same thing crossed my mind, but I don't know if it is one of those things that is simply ignored (a rule on paper only) or maybe it refers to the Pro cars or something in Comp. I can't see where any car with factory seating will accomodate the dimensions specified in the rule book.

_ken :w
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,236
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
Further clarification, hopefully...

The rules I cited above were taken from the General Regulations section of the NHRA rulebook. It has come to my attention that we need to clarify the rules a little, and I will attempt to do just that, but I'm probably going to get as lost as anybody here.

In the West Coast Corvette Challenge forum, Edgar (REDGAR) pointed out to me that we (the WCCC) use the rules in Section 1A for Super Pro, Pro and Sportsman racers. The following regulations governing roll bars and roll cages come from that section.
Section 1A, Frame: 4
ROLL BAR

  • Roll bar mandatory in all cars running 11.00 (*7.00) to 11.99 (*7.49), in convertibles running 11.00 (*7.00) to 13.99 (*8.59), and in all dune-buggy-type vehicles running 12.00 (*7.50) seconds and slower. Permitted in all cars. See General Regulations 4:10, 10:6.

ROLL CAGE
  • Roll cage mandatory in cars running 10.99 (*6.99) or quicker or any car exceeding 135 mph. In full-bodied cars, with unaltered firewall, floor, and body (from firewall rearward, wheeltubs permitted), running between 10.00 (*6.40) and 10.99 (*6.99), roll bar permitted in place of roll cage. In convertibles running 10.99 or quicker or exceeding 135 mph, roll cage mandatory. Cars running between 7.50 (*4.50) and 9.99 (*6.39) must have chassis inspected every three years by NHRA and have a serialized sticker affixed to cage before participation. Plating of chassis prohibited for all cars manufactured after 1/1/2003. Effective 1/1/2003, rear-engine dragsters must conform to SFI Spec 2.7A; vehicles exceeding 170 mph must meet appropriate SFI Spec for body used. All others must conform to specs for body style used, as listed in General Regulations 4:11, 10:6.

* 1/8 mile

I realize now I left out the regulation 10:6 from the original post here. I shall now atone for that mistake.
10:6, HEAD PROTECTOR
  • In any car where a roll bar or a roll cage is installed, a padded head protector must be provided at the back of the driver's head and constructed in an attempt to prevent whiplash upon impact. The roll bar or cage must be padded wherever it may come into contact with the driver's helmet. Adequate padding should permit minimum 1/4-inch compression or meet SFI Spec 45.1. The use of weather stripping and similar thin or low impact resisting materials is prohibited. A padded roll bar or cage alone is not acceptable as a padded head protector unless it is within 4 inches of the driver's helmet. A seat that incorporates a reinforced head rest is permitted.

Let the questions begin. :upthumbs

_ken :w
 
O

okieracing

Guest
3" above the helment I think is for a convertible only. If you have a hard top then its to the roof. On a hard top you have the roof to protect you as well as the roll bar. In a convertible you need the extra 3" to keep your head from touching the ground when a car is upside down.
:v

okieracing
 
R

REDGAR

Guest
4"s from the head to the rollbar is pretty short but I think we cover are within spec with the rollbar padded and the seat up against it.
 
B

BigBoyzToyz

Guest
enforced for verts in Hawaii

Yep, as soon as I broke 13.986 at the track here, they told me I had to either slow down or put in a roll bar. So...supposedly I can still practice my launches without one.

Hate to modify the sweet thing tho; I'm sure it would hurt the resale value.
.
 
R

REDGAR

Guest
There is an 1/8 mile ET as well you have to stay under. The track may not enforce it since only you and them see the ticket.
 
W

wallstAL

Guest
Good info, but these sanctioning bodies need to get into the 21st century!
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,236
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
Welcome to the Corvette Action Center wallstAL

Al! You finally found us!! Welcome aboard. :upthumbs
 

KOPBET

Well-known member
Joined
Jan 31, 2003
Messages
1,355
Location
Tulsey Town
Corvette
'73 Silver LS4 4 speed
walstAL

Nice pics BTW on your site. It is a shame that you choose to associate yourself with others that use this crap to trap people.

Update%20Privacy%20Protection%20Update.gif
 
A

Arnie

Guest
Rule change for 2004

I found this on the NHRA website:

E.T. brackets
In Super Pro, Pro, and Sportsman, T-top design vehicles will be required to have a roll bar if the car runs between 11.00 and 11.99; and a roll cage if the vehicle runs 10.99 or quicker.

Here's the page: http://www.nhra.com/2003/news/october/102302.html

It doesn't say anything about an unaltered firewall or floor.

Someone has already checked with the NHRA and states this has been posted in error, but until it is pulled off their website I'll wait and see what happens. I just had a 6-point roll bar installed and don't want to put a cage in the car.
 

fastglass95

Well-known member
Joined
Jan 27, 2001
Messages
208
Location
St. Peters, MO.
Corvette
1996 LT4 coupe + 2004 Z06 Z16
Re: enforced for verts in Hawaii

BigBoyzToyz said:
Yep, as soon as I broke 13.986 at the track here, they told me I had to either slow down or put in a roll bar. So...supposedly I can still practice my launches without one.

Hate to modify the sweet thing tho; I'm sure it would hurt the resale value.
.


FYI: I belive in NHRA you can run a "factory" hardtop on a C4 convertible Vette and they treat it as a coupe. So you would be O.K. with a factory hardtop down to 11.99 seconds in 1/4 mile.

Now, if only NCCC would agree with NHRA on the hardtop issue!
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,236
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
Nice! :cool

I thought of doing mine in silver, but I stuck with stealth black - it hides in the interior better. ;)

What did you use to paint it? I used POR-15 on mine.

interior_0313_03_320.JPG
 

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