NHRA Introduces Factory Experimental Exhibition Class
NHRA has been trying to get more interest for its Camping World Drag Racing Series Pro Stock category, one that’s actually one of the most technically competitive in the four-class Camping World family. While dominated by the Chevrolet Camaro car since electronic fuel injection replaced carburetors in 2016, Pro Stock just hasn’t captivated the interest of paying fans at its current 18-stop schedule.
To remedy this issue, NHRA has elected to bring in exhibition class Mountain Motor Pro Stock, which initially had some great acceptance from the fans who liked seeing the nostalgic cars with their nose-piece intakes. But just as with Pro Stock, this exhibition class didn’t fill stands as fans would circle the midways and pits while Pro Stock and Mountain Motor took to the track. It’s been a similar issue for Factory Stock Showdown: came out of the box with full steam and then deflated a bunch.
Now NHRA is proposing a new class that’ll take to the tracks during the 2022 season: Factory Experimental (A/FX) is reserved for 2019 and later manufactured vehicles with the factory production engine of the same make. At this point there are three accepted makes and models available for competition, although NHRA will happily welcome appropriate additions: Chevrolet’s COPO Camaro; Dodge’s Drag Pak Challenger; Ford’s Cobra Jet Mustang. All three models carry a minimum weight of 2,650 pounds, including the driver, or about 1,000 pounds lighter than a Factory Stock Showdown machine. NHRA, of course, reserves the right to adjust minimum weights, supercharger pulley ratios and other malleable settings to preserve parity in this exhibition class.
A run-down of rules for each automobile accepted for competition in the A/FX category includes certain accepted engine, transmission and suspension combinations:
The 2020 Chevrolet COPO Camaro 350 uses a 2.65-liter Magnuson 620-horsepower supercharged engine with an upper supercharger pulley size of 3.125 inches. The supercharger’s rear jackshaft cog pulley may contain 32 teeth while the rear cog pulley has 34 teeth. The 2021 Dodge Challenger Drag Pak 354 has the 3.0-liter Whipple engine, also with 630 horsepower. The upper supercharger pulley size is 3.375 inches while the lower engine pulley is eight inches. The 2019 Ford Mustang Cobra Jet 327 runs a 610-horsepower supercharged 3-liter Whipple engine with an upper supercharger pulley size of 3.750 inches and a lower engine pulley of 6.938 inches.
In this A/FX class, neither body, drivetrain nor chassis may be altered, modified or relocated – except as outlined in the NHRA specification chart. At the conclusion of each run, the minimum weight on the rear axle must be 1,300 pounds, including the driver.
Engines in this class must be the correct casting number for the year the race car is constructed, although NHRA-accepted aftermarket engine blocks are permitted. Cylinder bores may not exceed .080-inch over stock. Aside from normal balance jobs, the lightening of component parts is prohibited. CNC porting of both intake and exhaust runners, and to the combustion chamber are permitted, but changing configuration is banned. Spark plug holes must maintain the stock location, size and angle as machined by the OEM. Wet sumps with a single stage external oil pump are permitted, and the accepted A/FX ECUs will allow larger fuel injectors (one per cylinder), provided mods to or re-drilling of manifolds is not undertaken. All cars must use an NHRA-accepted lower engine oil-retention device, or use a belly pan in lieu of the original device attached to the engine. Engine setback has not yet been determined.
Purists will love the specification of a manual transmission; NHRA will allow aftermarket planetary or clutchless transmissions with a maximum of five forward speeds (plus reverse). Automatic transmissions are prohibited, making each individual shift a function only by the driver and controlled manually. NHRA has specified a maximum of three clutch discs with a minimum six-inch diameter and clutch release operated manually by the driver’s foot. Brakes, too, must be driver-operated and four-wheel hydraulic disc brakes are mandatory. At the same time, carbon fiber brake rotors – used together with carbon fiber specific pads, both front and rear – are mandatory, with all other materials prohibited. Stock-type steering in the as-located production destination is mandatory. Production 4-link suspension systems are permitted with a single hydraulic damper required per wheel (four maximum). Active suspension is prohibited. The wheelie bar length is a maximum of 66 inches.
NHRA is permitting ballast for the A/FX exhibition class with a maximum of 30 pounds. Ground clearance must be a minimum of three inches from the front of the car to 12 inches behind the centerline of the front axle. Clearance is two inches for the balance of the car, except the oil pan and exhaust headers. Dual parachutes are mandatory.
Bodies on these three – and any other models ultimately accepted by the sanctioning organization – must be accepted by NHRA, using OEM dimensional steel roof, steel quarter panels, A pillars and rockers. No chopping channeling, sectioning to the contour, length or width of any body panel is permitted. Doors must be functional to OE dimensions. Bumpers must be stock-appearing and consistent with the year, make and model claimed. Rear spoilers are mandatory, with a length of 14 inches, measured from the body line/spoiler transition point to the rear of the spoiler. A 90-degree wicker bill, too, is mandatory. Tires are restricted to 10.5W x 33 x 16, with a required height of the front tire at 26 inches. Rear wheels must meet a minimum SFI Spec 15.1, measuring a minimum of 16×16 inches, of a double deadlock design.
The specs are in and the interest in this new exhibition category is beginning to mount, even after less than a week. Will this class augment or replace Pro Stock and/or Factory Stock Showdown? Competitor and factory interest will be the ultimate determinator, but it’s always good to see NHRA trying to get more manufacturer interest in both competition and the added benefit of midway shopping between rounds.