Basic NHRA Rules and Tech inspection

white95

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Even though passing tech inspection seems a hassle, remember that safety is the primary concern. But, tech inspection doesn't have to be a drag if you know and follow the rules- remember that as your car gets quicker, the rules get stiffer. This story is not a complete list-for that you'll need to consult an NMCA, NHRA, or IHRA rule book, or talk to local track officials for specifics.


Common Stuff That'll Get You Busted

General Safety Check: Most tech inspectors do a basic vehicle-safety check that includes: checking for functioning brakes, verifying that at least one brake light works, checking the steering for excessive play, checking the driver seat for solid mounting, looking for loose objects (clothes, tools, portable boom boxes, tapes/CDs, and so on), and checking the function of the inside door handles for a hasty exit.


Bogus Battery Hold-down: Your battery must be held down with a fixed metal strap, not a cheezy rubber one, a tie-down, rope, or tape. Factory hold-downs are usually OK.


No Puke Tank: If your engine uses liquid coolant, then you've gotta have a radiator overflow tank (minimum 1 pint) with the proper hoses to prevent coolant from spraying onto the track during an engine overheat.


No Driveshaft Safety Loop: In most instances, if your car goes 13.99 or quicker or runs slicks, you're required to have an approved driveshaft safety loop (mounted within 6 inches of the front U-joint) that's at least 1/4-inch thick and 2-inches wide and provides 360 degrees of driveshaft en-closure.


Bogus Throttle Return-Spring Setup: Throttle control must be manually operated by foot and be fitted with two positive-acting return springs attached directly to the carb throttle arm.


Funky Fuel Line: There can be no more than 12 inches of rubber fuel line throughout the car. Approved braided-steel fuel line (as well as approved woven-type line with push-lock connectors as available from Aeroquip) is accepted. Inline glass fuel filters are prohibited, except for stock factory-offered setups plumbed with original hardline tubing.


No Reverse Lockout/No Neutral Safety Switch: In most instances, non-OEM transmissions with a floor-mounted shifter must be fitted with a shifter that has a spring-loaded Reverse lockout. In addition, there also must be a functional Neutral safety switch that prevents the engine from being started while the car is in gear.


Rollbar Requirement: Any open-roof or convertible car running 13.99 or quicker must have a minimum of a five-point rollbar to race. For those running 10.99 or quicker, an eight-point (or more) rollcage is required.


Hardtop cars must have at least a five-point rollbar when running 11.99 or quicker and a full rollcage (eight-point or more) when running 9.99 or quicker.


Missing Lug Nuts: There must be proper-style and thread-engagement lug nuts for every wheel stud. If you've got a broken stud, it doesn't mean that you can do without-you've got to fix the stud and use a lug nut! In addition, aftermarket wheel studs must protrude through the lug nut at least the diameter of the stud, and all lug nuts must be of the open-end variety. Capped nuts are prohibited.


Seatbelts: In most instances, vehicles are required to have seatbelts attached directly to a reinforced floor or frame mount. A car that is required to run a rollbar or rollcage must have approved aftermarket five-point restraint belts. Such belts must be recertified or replaced every two years.


No Leakers: It's simple: If your vehicle leaks any type of liquid or crud (oil, water, fuel, grease, and so on), you won't be allowed to run.


General Rules
Wheel Spacers: In general, there's no set rule regarding wheel spacers. However, when tech inspectors see spacers that are 3/4 inch or thicker, you may have problems. In most instances, bolt-on wheel adapters are acceptable.


Auto Tranny Shields: Vehicles running 10.99 or quicker (or over 135 mph) must have an SFI-approved tranny shield or tranny blanket.


Auto Tranny Flexplates: Vehicles running 9.99 or quicker, or over 135 mph, must have an SFI-approved flexplate and flexplate shield.


Bellhousing/Scattershield: Manual tranny cars running 11.99 or quicker must have an SFI-approved scattershield with a proper shattershield-to-block plate.


Helmet Requirements: If your car runs 13.99 or quicker, you'll be required to wear a SNELL- or SFI-approved helmet. A valid SNELL or SFI sticker must be visible on the inside of the helmet, and the helmet must be in good visual condition (no cracks, chips, gouges, and so on).


Ballast: In most classes, add-on ballast is allowed as long as it's properly located and fastened to the vehicle. Tech inspectors prefer to have the ballast contained within an approved ballast box or welded to the car. Bolt-down boxes must have two 2 1/2-inch Grade 8 retention bolts per every 100 pounds of ballast. Loose or liquid ballast is strictly prohibited.


Rollbar/Rollcage Mounting: Regardless of the type, mounting must be to a frame with full-frame cars and to approved 6x6x0.125-inch steel plates welded to the floorboards (shown) for unibody cars. Chrome-moly steel tubing must be welded by TIG heliarc method, and mild steel tubing must be welded using either the TIG or MIG wire-feed method.


Other Rollbar/Rollcage Stuff: The bar/'cage must be no further than 6 inches behind the driver's head, must extend at least 3 inches above the driver's head, must be at least as wide as the driver's shoulders, and must include a driver-side sidebar that intersects the seated driver at a point between the shoulder and the elbow. Wher-ever the bar/'cage could come into contact with the driver's helmet, there must be SFI-approved padding. When a rollcage (eight-points or more) is required, an approved driver's window net is also mandatory.


Fuel and Brake Lines: Most tech inspectors prefer lines to be mounted inboard the framerails in locations free from excessive heat, sharp edges, or kinks. As of January 1, 1999, NHRA prohibits the fuel line from being run inside the actual framerail tubing.


Axle-Retention Devices: In most instances, any car running 10.99 or quicker, or any car running a locking or spool-type differential, must be upgraded with a C-clip eliminator kit (when applicable).


Aftermarket Axles: Any car running 10.99 or quicker must upgrade to approved non-C-clip-type aftermarket axles.


Drag Slick Stuff: Although tire antirotation devices (such as rim screws) aren't required in most e.t. or Sportsman class racing, they're highly recommended. However, when running 11.99 or quicker, all wheels must be upgraded with metal, screw-in valve stems.


Fuel-Pressure Gauge Location: Installing a mechanical fuel-pressure gauge in the cockpit without an approved fuel isolator is strictly prohibited. Mounting a fuel-pressure gauge on the hood or cowl without an isolator is usually OK.


Battery Relocation: The battery may not be in the driver's compartment. When relocated to the trunk, it must be in an approved battery box bolted directly to the frame by at least two 3/8-inch bolts (no J-hooks). A battery cutoff switch and rear firewall is mandatory.


Battery Cutoff Switch: A battery cutoff switch if required on all cars running 9.99 or quicker or over 135 mph. The switch must be wired to the positive side of the electrical system and must be clearly labeled with the "off" position at the rear of the car.


Nitrous/CO2 Bottle: The bottle must meet (and be engraved) with the minimum 1,800-pound DOT rating. It must be securely bolted down (no hose clamps, tie-wraps, or tape) and must be properly vented to the outside of the car when located in the driver's compartment.


Reverse: You can't have your buddies push your car back for you.


Sharp Metal: There's no set rule regarding body-panel finish. However, if tech officials feel that a sharp edge or protruding corner poses a potential problem, you're out. Radiused rear wheelwell openings require the sharp metal lip to be rolled upward.
 

RichV

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Stock closed lugs are OK tho right? I've never been questioned about them.

Also, they would not let me run my road race car because I have no windows. Not sure if this is some rule, because I've seen Cobra kit cars run, or they just didn't want to let a road race car out. :)
 
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white95

white95

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The big sanctioned race events don't slide on the rules much but test n tune nights usually are a bit more lenient. As for the windows, if you had window netting, they should let you run.
 

RichV

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Yea dunno, they wouldn't. I had my Foxbody #71 out at a Ford Day at the local strip.
 

Suspect

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starting to read up on all these rules. want to be ready for when we open up. i guess i need to start looking for a helmet. also did not know about the driveshaft safety loop. i have one, but its not on the car.
 

duff daddy

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starting to read up on all these rules. want to be ready for when we open up. i guess i need to start looking for a helmet. also did not know about the driveshaft safety loop. i have one, but its not on the car.

Funny thing is I dont actually have a loop I have a flat bar that looks like a loop haha. Helmets are good buys at pawn shops

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Suspect

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I got a helmet before I went.. then I got there I needed a jacket. :( still got to run twice. ill buy my jacket here soon.. just waiting on my wheels.
 

99GreenStang

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Some of these rules are just ridiculous rules that try to make you buy expensive parts for nothing. Man needs a helmet and a fire proof suit and a car that will go and stop , any other accidents are on him lol .

Question seeing as I don't do drag racing as I've always been in Dirt track racing why do they want you to have aftermarket non C clip axles ?


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duff daddy

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Question seeing as I don't do drag racing as I've always been in Dirt track racing why do they want you to have aftermarket non C clip axles ?


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This is 1 if the carrier fails, the axles wont fall out the end tubes, basically takes a c clip rear end and makes it similar to a 9"


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