Heavy Hitters | Diesel Truck Heads-Up Class

HEAVY HITTERS - Diesel Truck Heads-Up Class

MANDATORY RULES — No Exceptions — Violation = DQ + No Refund 

1. Mandatory Inlet Air Restrictor Tube

Every competitor must run the provided inlet air restrictor tube (supplied with the entry fee). The restrictor is a 3D-printed tube measuring 4" OD × 6" long, featuring a rib on each end to secure a rubber coupler/boot. Competitors with a 4" inlet turbo (S300, Stock appearing, etc) will be sent a slightly larger restrictor tube based on Firepunk's dyno testing to target 750-800 hp maximum effort. 5" inlet turbochargers (S400 and the likes) will be sent a slightly smaller restrictor tube with a 4" to 5" rubber coupler and two T-bolt clamps.

•    The restrictor may be mounted directly on the turbo face or at any distance away from the turbo face (long or short intake tubes are allowed).
•    Clamps must remain tight and secure at all times. No loose clamps are permitted.
•    The intake must be completely sealed. No holes, no gaps, and no leaks are permitted in the intake tube or connections.
•    All air entering the face of the turbo must pass through the restrictor tube. Any modification that allows air to enter the turbo without passing through the restrictor tube will result in a disqualification.
•    No modifications to the restrictor are allowed.
•    The restrictor must be present, properly installed, and unaltered for all tech inspections.
•    If the restrictor tube or intake falls off during the competition (while the truck is racing), the competitor will be disqualified and that round results in a loss.

2.    Engine Management

•    Factory OEM ECM only (Dodge/Ram, Chevrolet/GMC, or Ford).
•    Engine swaps/repowers allowed, but the engine must be 100% controlled by one of the three OEM ECMs listed.
•    No aftermarket/standalone ECM controlling fuel (MoTeC, Bosch, Haltech, Holley, FuelTech, etc.). Data loggersand transmission controllers are permitted only if the truck continues to run with the aftermarket unit unplugged.
•    OEM ECM may be tuned, unlocked, or reflashed.

3.    Intercooler

•    Air-to-air intercooling only.
•    Liquid, CO2, ice, or any other supplemental intercooler cooling systems are prohibited.
•    Exception: Factory 6.7L Power Stroke may retain its factory air-to-water system only if using OEM-style heat exchanger, water pump, and plumbing (drop-in core allowed). No ice, remote tanks, secondary pumps, or extra reservoirs. Switching to air-to-air is allowed and recommended.

4.    Transmission, Launch & Suspension

•    Foot-brake only.
•    No trans brake, no bump box.
•    Standalone or aftermarket transmission controllers are allowed.
•    Trans-brake buttons must be disconnected if the valve body is equipped.
•    No aftermarket 4-links. Stock or aftermarket leaf-spring, factory 4-link, or equivalent stock-appearing suspension only. No fabricated or racing-specific 4-link setups.

5.    Fuel / Power Adders

•    Diesel fuel only.
•    Nitrous, water/meth, propane, or any other injectables/power adders are 100% banned.
•    No bottles, solenoids, lines, nozzles, brackets, or hidden systems of any kind.
•    Any evidence found = immediate DQ and ban from future Heavy Hitters events.

6.    Weight

•    7,000 lb minimum with driver (weighed post-run).
•    No margin of error (6,999 lb = DQ).
•    All ballast must be bolted or welded in place. No temporary straps or removable weights.

7.    Turbocharger

•    Factory 4" or 5" compressor inlet turbos only.
•    4" inlet turbo competitors will be sent a slightly larger restrictor tube based on Firepunk's dyno testing to target750-800 hp maximum effort.
•    5" inlet turbochargers will be sent a slightly smaller restrictor tube.
•    Turbos that were manufactured with 5.5" or 6" inlets and machined down to 5" inlets are prohibited.
•    5.5" and 6" inlet turbochargers are not allowed.
•    No aftermarket housings or modifications that increase the effective inlet size beyond the original factory inlet.
•    Turbo must remain in as-manufactured condition regarding the inlet; no machining, porting, or adapters that enlarge the inlet.

8.    Safety

•    Competitors are responsible for meeting current NHRA/IHRA safety equipment requirements for their projectedET and speed.
•    Helmets, seatbelts, and other required safety gear are the driver’s responsibility based on performance level.

9.    Racing Format

•    Heads-up.
•    Instant green (no amber on the tree).
•    Chip-draw pairings every round (no fixed ladder).
•    Win light only — no timeslips shown or given.
•    Single elimination.
•    Red light = loss (first foul loses in the event of a double red).

10.    Inspections

•    Pre- and post-race checks: weight, restrictor presence/condition and correct size for the turbo, turbo inlet verification, and visual sweep for nitrous or other power adders.
•    Restrictor must match the provided unit exactly for the competitor's turbo type.
•    Tech officials have final authority on all compliance decisions.

11.    Tires

•    Minimum 400 treadwear rating (examples: Nitto 420, Toyo Proxes, or equivalent DOT street tires).
•    No slicks, no drag radials rated below 400 TW, and no race-specific tires.

*These rules are intended for a proof-of-concept heads-up race and may be refined for future events. Competitors are responsible for knowing and complying with all rules prior to arrival. Questions should be directed to the event organizer before the race.