Class Rep: Tom LaRue
All NTPA rules must be followed
Drawbar length, 18 inches. Drawbars cannot be shorter or higher than specifications listed. Drawbar lengths are measured from the
center of rear wheels to the point of hook.
Drawbar Height 30 inches
Class weight not to exceed 6,200 lbs.
1) The maximum length of the vehicle is no more than 15 feet from centerline of rear axle to forward most portion of the vehicle including
2) The 15-foot from center of rear axle overall rule will apply to all TWD vehicles with the exception of a 10-inch over-length allowance for
cosmetic fiberglass only. No steel structure, re-enforcement, or steel bumpers allowed past 15 feet.
NOTE: this allowance applies only to pickup truck-style bodies of the following models: 1994 Dodge or newer; 1996 Fords or newer; and 1998 Chevy and/or
GMC or newer.
3) Must run a minimum of 14- inch front rims with an automotive or front tractor tire.
4) Any wheelbase is permitted.
5) Front wheel and axle to remain in the visual center of the front wheel well. Maintain minimum of 2 inches of complete original type
wheelhouse forward of front wheel. Must be able to see forward most part and rearward most part of tire from a side view.
6) Maximum width of vehicle is 8 feet.
7) Weights are not to extend forward of maximum length stated in Rule a:1 above, nor rearward more than 12 inches from hitch point and
must not interfere with hitching and unhitching of vehicle.
8) Any factory production body truck or van is allowed, including passenger-type bodies.
9) Funny car-type body and/or fiberglass body must have escape hatch or doors in top or back of body.
10)Vehicle must have a presentable van/pickup bed with cover or flatbed in place.
11)Chassis (frame) may be truck frame or fabricated frame like Modified tractors.
12)Vehicle must have hood, grill, and fenders in place as intended by manufacturer.
13)Vehicle body style must be or have been available from a dealer as mass produced.
14)Vehicle must maintain original appearance.
a) Fiberglass hood scoops, spoilers, fender flares are allowed.
b) Allowed to use stock appearing pickup truck and van fiberglass bodies and body parts.
16)Driver must be in original driver compartment.
17)Side doors must be mounted and closed if vehicle was manufactured with doors.
18)Vehicle doors must have a single latch design, allowing the door to be opened from both inside and outside.
19)Flip-top-body type vehicles and vehicles that do not have two (2) working doors must have door glass lowered or removed while under green flag.
20)Vehicles with less than stock size window openings must have an escape hatch with a minimum size of 17 inches x 18 inches, or
large enough for driver to exit.
Note: Escape hatch will not be counted as a working door.
21)All TWD vehicles must have a presentable front windshield of glass, plexiglass, or lexan. Factory-tinted glass acceptable. Stained or
smoke glass not allowed. Tinted windows that impair track official’s view of drivers compartment not allowed.
22)Vehicles in this division must have vertical bumpers at the rearmost point of the vehicle. Bottom of bumper to be a maximum of 24
inches from the ground. Bumper to extend minimum of 8 inches vertically. Must be rigid.
23)Hood line variance: original hood line should be kept and a 3-inch maximum clearance opening will be allowed for speed equipment.
1) Torque converters, automatic shifts, etc. are permitted.
2) No electronic, pneumatic or hydraulic device that effects the clutch system allowed. All staged or variable released clutches of any
(This does not effect slave cylinder for clutch pedal)
C: Driveline Shielding
Without planetary rearend:
1) If planetary rearend is not used, transmission to final drive,
a) Vehicle must have (3) round metal loops shielding on each drive shaft (two-piece drive shaft must have six metal loops).
b) 360 degree loop must be a minimum of 3/8-inch aluminum or 5/16-inch steel, ¾ -inch wide (or wider) and not more than 2 inches from the shaft in
c) End loops to be placed no farther than 6 inches from universal joints, with third loop in center of shaft.
d) May use a solid tube (3/8-inch aluminum or 5/16-inch steel) to meet the above requirements.
2) Drive shafts between engine and transmission must have solid shielding a minimum of 3/8-inch aluminum or 5/16-inch steel.
3) Vehicle must have 360 degree metal shield around the universal joints, 3/8-inch aluminum or 5/16-inch steel, minimum width 6 inches.
Note: If a split design is used, mount as in Rule 6:a. below.
4) Axle and hub bolt shield required, except where planetary final drives are used.
a) Shield must be at least 0.060-inch thick.
b) Minimum diameter of axle end or hub bolts to be covered on both front and rear axles.
c) Mounting shield may not be mounted to axle end or hub bolts.
d) A hole may be installed in center of front shield so lock can be operated, so long as hub end or axle bolts are covered.
5) No counter balancers permitted in driveline.
With planetary rearend:
6) All remaining drive train, excluding additional manual transmissions, must be enclosed in 5/16-inch minimum steel or 3/8-inch aluminum,
round, inside diameter not to exceed 2 inches more than the outside diameter of the largest universal joint, fastened every 6 inches or closer,
with 3/8-inch or larger bolts (Grade #5), or butt and seam welded, and securely mounted to vehicle’s frame. Applies to all vehicles with
exposed drive shaft. No more than 1/4–inch of end of driveline shall be visible with driveline shielding in place.
Note: If U-joints are used in any drive shaft application, the shielding must be 5/16-inch steel or 3/8-inch aluminum with 1/8-inch steel
insert in aluminum. The insert must be a minimum of 6 inches wide.
a) All TWD vehicles engine/automatic transmission combinations must have either:
i) Two front engine mounts, two rear engine mounts and support saddle for rear of transmission, with 1/2 –inch maximum
ii) Two front engine mounts, support saddle at rear of engine, with ½-inch clearance, and a mount at rear of transmission.
Note: This is to prevent engine or transmission from dropping if breakage occurs.
7) TWD vehicles with a driveshaft of 60 inches or longer must have a minimum 2-inch nylon strap in the middle of that span to secure
the driveshaft shield to the frame.
D. Engine/Engine Limitations
1) Vehicles are limited to a single automotive-type engine.
Note: Automobile engine is any engine or it’s replica available in a passenger car. Maximum (8) cylinders. A replica to be considered legal
must accept and swing a stock crankshaft. No diesel engines permitted.
a) At all levels of TWD competition – a limit of 575 cu. Inc. and two valves per cylinder.
2) Engine must be in stock location, which is defined as being within engine compartment as manufactured, behind stock grill, and in front of stock
3) Vehicle may run without radiator, and engine may be moved forward, but engine must stay behind the grill.
Note: Entire engine to mean anything that is bolted to the engine block.
4) Except for high performance type starters with crank shaft drive, rear of engine block may not be moved forward of center line of
5) Allow only single staged turbochargers, 1 per bank in this division, and must therefore follow the safety rules that apply to all
a) Turbochargers that are not under the hood must be completely shrouded, except for inlet and exhaust pipes, with steel or aluminum of
at least 0.060-inch thickness.
b) Turbochargers under fiberglass hoods must be completely shrouded, except for inlet and exhaust pipes, under the area of the fiberglass
with steel or aluminum of at least 0.060-inch thickness.
c) Intercoolers located outside of normal engine shielding must be shielded the same as turbochargers not under the hood. Must be
shielded with steel at least.
d) Supercharger limit: maximum size 14-71, 19-inch rotor case length, 11.25-inch rotor case width. Helix restricted to a maximum rotor
spiral of 6.5 degrees per inch of rotor length. Variable multi-speed supercharger devices prohibited.
i) All superchargers must be mounted to the intake manifold by use of aluminum studs only. (No steel studs allowed.)
ii) Supercharger restraint system is mandatory and shall consist of four separate straps, one on each corner of the supercharger, with each
strap securely fastened to the engine by means of it’s own attachment bracket. The top attachment bracket to be sandwiched between the
lower surface of the injector body and the upper surface of the supercharger case. The bottom attachment bracket for each strap shall be
connected to the engine by a minimum of one 5/16-inch bolt or stud (SAE Grade 5 or better).
e) Supercharger drive components must be shrouded on the top and sides with 0.060-inch metal.
i) The shield must be wider than the drive belt or chain, and be securely mounted.
ii) Blower belt shield must be wider than all components, idler, belt, pulleys, etc., and extend to bottom of bottom pulley or below.
f) Carbureted or injected Allison, Packard, Industrial or Marine engines using a centrifugal supercharger must be shielded.
i) Shield to start at the center line of supercharger housing and extend 5 inches rearward, notching allowed only to fit around accessory
ii) Shield must extend 8 inches forward of center line of blower housing and notched only for accessory components (such as air boxes).
iii) On front edge of the shield there must be a rolled lip extending inward 1 inch.
iv) Shield must be 3/8-inch steel, bolted every 2 inches or closer, with 3/8-inch bolts (Grade #5 or better) or larger.
v) Shield must start at bottom of blower housing, up side, over top and down other side to bottom of blower housing. Holes or notches
allowed only for accessory components. Shield must maintain it’s integrity.
vi) Shielding must be the same on each side of the supercharger. (SFI Spec. 4.1)
h) No cutting or grinding on Allison supercharger wheels.
i) Allison blowers must have a steel shield as in rule g) i to vi above, or an SFI Spec 4.1.
j) On pulling vehicles the tubing on the pressure side of the turbocharger or supercharger to the intake must be under the hood or side
shields, or bolted or strapped securely.
k) All supercharged engines with blower drive facing the driver must use SFI Spec. 14.1 blower restraints.
l) Screw-type superchargers are not permitted for competition vehicles.
6) Competitor must disable one ignition system by means other than a switch; i.e. removal of spark plug wires on either end or by removal
of the distributor for that system.
7) Automotive engines are only allowed to run a maximum of (2) valves per cylinder head and one spark plug per cylinder.
8) Fuel injection (and carburetors) and headers may protrude through the hood.
Note: Bubble or scoop is optional, but if used, the scoop or bubble must cover the carburetor(s) of fuel injection, if induction
system protrudes through the hood.
9) Vehicle must have vertical exiting exhaust. Height of pipe must be a minimum of one foot above the bend.
Note: Vertical is defined as “being in plumb,” with a 10-degree variance in any direction
1) Tubular steel frame is allowed.
1) Vehicle must have floor or bed cover.
2) Vehicle may compete without tailgate or rear door(s) for greater hook point visibility.
3) No portion of vehicle may interfere with sled, chain or hook during pull or while being hooked or unhooked.
4) An area 5 inches wide and 12 inches high immediately above and below the drawbar must be free of all obstructions (including weights,
wheelie bars and second drawbars) for ease of hooking and unhooking.
a) If body extends more than 12 inches behind point of hook, the open area must be 18 inches above drawbar and 24 inches wide at
rear most point of body.
5) Vehicle must have tow hitch on front of vehicle.
a) It may extend no more than 6 inches ahead of the farthermost front portion of the vehicle.
b) It will not be counted when measuring length of vehicle.
c) It must have a 3-inch diameter hole, positioned horizontally.
d) It must be strong enough to push or pull the vehicle at it’s heaviest weight.
e) It is to be used only for pushing or pulling the vehicle.
1) Vehicle must have a complete firewall with no holes except for controls. Holes not to exceed ½-inch larger than control.
2) Vehicles that do not have working doors must carry an onboard halon fire system with a minimum of (3) nozzles located within the
driver’s compartment/engine compartment.
3) Flip-top bodies or funny car type vehicles must have body in lowered position before vehicle may be moved under it’s own power.
4) Flip-top type bodies must have a safety lock to hold up the body.
5) Body may be raised to start engine and may stay in raised position while engine is running as long as vehicle is not in motion.
6) Operator’s Compartment:
a) No radiator, heat exchanger and/or water hoses allowed inside operator compartment.
b) If battery is inside operator’s compartment, it must be safely enclosed and securely fastened.
c) No fuel tanks, fuel pressure gauges, fuel pumps and/or fuel lines inside operator’s compartment.
d) If the fuel tank is located behind the driver, a fire barrier is required from the firewall to the rear of the driver’s seat. (0.060-inch
aluminum or steel is acceptable fire barrier material.)
Rear tire diameter shall not exceed 143-inch circumference when mounted on an 18-inch rim and inflated to 28 psi. The ground patch is
not to exceed 19 inches based on original tread.