Some general NHRA rules:
-All cars must have a catch can for radiator overflow of at least 1 pint. These must be securely fastened (bolted or clamped). Factory overflow in most late-models is fine.
-Neutral safety switch (again, if using a factory shifter, this should be already installed. Aftermarket shifters will require wiring this in).
-If battery is in the back/trunk (regardless of ET), a secured tray and cutoff switch is required.
-If using Nitrous oxide, the bottle must be securely mounted (no plastic brackets), bottle must be stamped with 1800-lb DOT rating and identified as nitrous oxide. If bottle is located in driver's compartment, it must be equipped with a relief valve and vented outside the compartment. Commercially available thermostatically controlled bottle-type warmers are permitted, all other heating of bottles prohibited (i.e. blow torches).
-Any vehicle using a spool center section requires aftermarket axles with positive retention (c-clip eliminators).
-NHRA national and divisional races require clear glass around the vehicle, subject to check. Local races vary, check with your division or track.
-Tires/Wheels/Studs and lugs/spacers:
Tires may be checked for condition, pressure, defects, etc. by a tech inspector before allowing runs. All street tires must have a minimum of 1/16 inch tread depth. Temporary spares, space saver spares or trailer tires prohibited.
Thread engagement on the lug must be equivalent to or greater than the diameter of the stud or bolt. Length of the stud/bolt doesn't determine permissability (example: a 7/16 inch stud must be thoroughly engaged through the threads in the hex portion of the lug a minimum of 7/16 inch.
Spacers are allowed and can be either hub centric or lug centric. Spacer can not reduce the minimum permitted thread engagement below the standards listed above. No stacking of wheel spacers allowed.
13.99 1/4-mile (8.59 1/8-mile) or quicker:
-A driveshaft safety loop is required when you run slicks (not drag radials or street tires). With street tires or drag radials, no loop is required until 11.49 1/4-mile (7.35 1/8-mile) and faster.
-A helmet (closed face or open) is required with a minimum Snell K98 or M2000/SA2000 rating. Helmets last 12 years from their rating date (example a Snell 2005 would be good until 2017). Shield is not required.
11.99 1/4-mile ( 1/8-mile) or quicker:
-Metal screw-in valve stems required on tubeless tires on all wheels.
11.49 1/4-mile (7.35 1/8-mile) or quicker:
-A 5-point minimum roll bar on a fixed roof car (t-tops okay as well if in place while racing) from 11.49 to 11.00 (7.00 1/8-mile). If the hardtop / t-top car has un-altered floors, firewall and frame rails (wheel tubs are okay), then the 5-point roll bar is good til 10.00 1/4 mile (6.40 1/8-mile). Convertibles require the 5-point bar from 13.49 (8.25 1/8-mile to 11.00 (7.00 1/8-mile). The rollbar must be constructed of minimum 1 ¾ inch o.d. x .118 inch wall mild steel tubing, or 1 ¾ x .083 chrome moly tubing. The roll bar can be bolted or welded to the floor, see diagram for specs. Roll bar must be padded anywhere the driver's helmet may contact it while in the driving position.
See diagram below.
The 5-points are:
-Main hoop; 2 "down bars" (bars that go from the main hoop rearward to the trunk floor/hatch area. These can be straight or bent like a "package tray" style, search for photos); Welded crossbar for belts (can't be removable); Driver side door bar (can be a swing-out. Many put a passenger's side bar in as well (6-point) because it strengthens the car on both sides, but if you have subframe connectors the difference may be minimal).
-Protective Clothing (SFI jacket with a 3.2A/1 rating, no expiration date)
-5 point harness (up to date, they must be replaced or re-certified every 2 years)
-SFI-approved flywheel and/or clutch (no expiration date)
-Screw-in valve stems
-No tint allowed on window except factory
10.99 1/4-mile (6.99 1/8-mile) or quicker:
-5-point roll bar is still okay to 10.00 1/4-mile (6.40 18-mile) in hardtop / t-top with un-altered floors, firewall and frame rails (wheel tubs are okay). If the floor and/or firewall has been modified, then a full roll cage is required beginning at a 10.99 e.t. or any vehicle running 135 mph or faster (regardless of e.t.). The roll cage must be constructed of minimum 1 5/8 o.d.x .118 mild steel tubing, or 1 5/8 x .083 chrome moly tubing. Roll cage must be padded anywhere the driver's helmet may contact it while in the driving position.
See diagram below.
-Convertibles require full roll cage at 10.99 and quicker.
See diagram below.
-aftermarket axles with positive retention (c-clip eliminators)
-Transmission shield SFI Spec 4.1 at 10.99 and quicker or 135 mph and quicker (blanket is okay, no expiration date)
-Harmonic Balancer SFI Spec 18.1 (no expiration date)
9.99 1/4-mile (6.39 1/8-mile)/ 135 mph or quicker:
-Roll cage is required on all vehicles at 9.99 and quicker or any vehicle running 135 mph or faster (regardless of e.t.). The roll cage must be constructed of minimum 1 5/8 o.d.x .118 mild steel tubing, or 1 5/8 x .083 chrome moly tubing. Roll cage must also be certified by NHRA every 3 years, and have a serialized sticker affixed prior to participation. The cage must be padded anywhere the driver's helmet may contact it while in the driving position. This style of cage is good til 8.50 1/4-mile times, then a funny car style cage is required.
See diagram below.
-Window net required (can be ribbon or mesh, no altering allowed unless done by manufacturer. No expiration date per 2008 NHRA rule book, but some have said 2 years on expiration/re-cert. Check with your local track or division).
-NHRA competition driver's license required, done by car designation (dragster, door car, etc). A physical, 2 NHRA licensed drivers to witness/sign your forms and minimum 6 runs are required.
-Flexplate SFI 29.1 and shield SFI 30.1 required (no expiration dates listed, but I believe the shield is 5 years)
-Protective Clothing (SFI jacket and pants with a 3.2A/5 rating, gloves and neck collar, no expiration date)
-Battery cutoff (regardless or whether battery is still up front or relocated to rear of vehicle)
-A full-face helmet is required with a minimum Snell K98 or M2000/SA2000 rating. Helmets last 12 years from their rating date (example a Snell 2005 would be good until 2017). Shield is permitted but not required. This rule posting is as it applies to cars like ours (closed body type). For open cars a different helmet ruling is required.
-A engine diaper is required at NHRA national and divisional races, local races vary, check with your division or track.
Parachutes:
-Required at 150 mph or faster, no matter the e.t.
http://www.nhraonline.com/contacts/tech_faq.html
Roll bar Diagram:
Roll Cage Diagram (good to 8.50 1/4-mile elapsed times):
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