From the NHRA Heritage series rules:
Junior Fuel:
Fire extinguishing system must meet SFI Spec 17.1. Minimum 5-pound, NHRAaccepted
fire extinguishing system mandatory. System must be divided with one
nozzle on driver’s side and one nozzle on engine.
A/Fuel:
Fire extinguisher system meeting SFI Spec 17.1 mandatory. A minimum 20-pound
system required with a minimum one nozzle aimed at the driver and one at the front
of the engine.
7.0:
Fire extinguisher system meeting SFI Spec 17.1 mandatory. Minimum 20-pound
or more NHRA-accepted fire extinguishing system mandatory on all front-engine
open-bodied alcohol-burning supercharged cars. Activation cables must be
protected in bellhousing and engine area. Activation cables and distribution
tubing must be steel. Must be installed per manufacturer’s specifications. Carbonfiber
bottles prohibited.
Nostalgia Eliminator (NE I, II and III)
Permitted; must be securely mounted. See General Regulations 9:3.
And here is the 9.3 section of the rules:
9:3 FIRE EXTINGUISHER
An onboard fire extinguisher system is mandated under certain Class Requirements. In
other classes, it is recommended that each contestant and/or his or her crew have a
loaded, serviceable fire extinguisher and a fire blanket in their possession, carried in the
tow vehicle, race car, or otherwise available for immediate use. Dry chemical or CO2-type
extinguishers, 2 1/2-pound minimum size, are recommended. When installed in a race car,
must be mounted in a secure manner; use of flip-open-type clamps prohibited.
When required, Nostalgia Top Fuel, Nostalgia Funny Car, fire extinguishing system must meet
SFI Spec 17.1 and be installed and utilized per manufacturer’s installation requirements.
For all other vehicles, onboard fire extinguisher systems must be manually controlled Cold Fire
302, Fire X plus, Halon FE1211 or 1301 or FM200, or F500, and mounted per manufacturer’s
specifications with the primary nozzle(s) directed in an attempt to protect the driver. Other
agents, classified on the EPA SNAP list as Acceptable Total Flooding Agents (Feasible for Use
in Occupied Areas) and NHRA accepted, may be used. Bottles and lines must be mounted
above the bottom of the adjacent framerails. Fire bottle activation cables must be installed
inside framerail where cables pass engine/bellhousing area. Bottles must be DOT-approved or
meet SFI Spec 17.1 and permanently mounted (no hose clamps or tie wraps). In the case of
more than one bottle, each bottle must have its own distribution tubing and nozzles. The use
of bottles, nozzles, or tubing other than that recommended by the manufacturer is prohibited.
Upon activation of the system, the contents of the bottle(s) must be totally discharged; partialdischarge
systems prohibited. The bottles must be mounted in such a manner that should an
explosion or failure of any mechanical component of the vehicle occur, the bottles will be
protected from flying parts. When installed in/on a race car, must be mounted in a secure
manner; use of flip-open-type clamps, hose clamps, tie wraps, snaps, etc. prohibited. They
should be protected from excessive temperature and mounted rigidly to the vehicle. Remote
cables must be metallic (plastic or plastic-wrapped cables prohibited) and installed so they are
protected in the event of an upset or collision. Follow the manufacturer’s recommendations
regarding installation, especially on bend radius, and protection from crimping or kinking. All
fire systems must use steel lines, steel or aluminum distribution nozzles, and must be
equipped with a pressure gauge. All bottles must be identified with a gross loaded weight
figure. It is the responsibility of the competitor to weigh the bottle prior to each event.
And if you read all of that it is once again a bunch of totally ambiguous BS that quite often contradicts itself. Every big show funny car on the planet uses plastic wrapped cables (the grey spiral bound Morse style) and nowhere in the NE section does it spell out that blown cars are required to have a 20 lb system despite the fact that tech inspectors are requiring just that because the regular NHRA rule book does actually state that "All front engine, open bodied supercharged or turbocharged (gasoline of methanol) cars must be equipped with an SFI-rated 20lb system". And what that means is that ANY car that fits those criteria must have a 20 lb system despite the fact that it may only run in the 10's or slower
In the 7.0 call out it says that the cables must be protected in the bellhousing area while the 9.3 call out specifies that they must be in the frame rail so there is more chance for different interpretations there as well.
A lot of the wording in the Heritage rules has been pulled straight from the regular rule book and that makes for some classic rulings like the one calling for an anti displacement collar on the steering column:
" A secondary steering shaft stop must be installed to prevent long steering shaft from injuring driver in case of frontal impact (i.e., collar or U-joint pinned at crossmember, bracket, etc.)." If the steering box gets pushed back in a front motor car I think that you are probably toast anyway.
Roo