2019 NPK Rules
NPK Vehicle Guidelines – As of 11.30.18
For Informational Purposes Only
1. No Prep Kings Tournament is a heads-up 1/8th mile class.
2. The use of dual power adders is prohibited. Water injection permitted on Nitrous combo only.
3. All entries must maintain the factory wheelbase of year, make, and model being used, + or – 3 inches maximum and an external/outwardly appearance for year, make and model being used.
4. Cars must have factory dimension full steel roof, full steel quarters, and OEM Factory VIN tag affixed. Steel panel overlays prohibited.
5. OEM composite body (Corvette) and OEM composite roof panel (4th Gen Camaro/Firebird) permitted.
6. Cars must be able to pass NHRA tech for the weight and speed that the cars run.
7. Cars will be weighed each Race and must meet minimum weight limitations/specifications.
8. All cars must have neutral safety switch in working order.
9. All cars must have working taillights.
10. Front / side exit style headers must have turn ups or be directed away from starting line sensors.
A. Weight Limitations/Specifications
All vehicles shall be weighed each Race and must conform to the following criteria:
Nitrous (over 5.00”)
Twin Turbo – Up to 88mm
Twin Turbo – Larger than 88mm
Twin Turbo (500 CI +)
Centrifugal up to 136mm
Centrifugal 137 to 145mm
Centrifugal 146mm and above
Twin Turbo – Up to 88mm
Twin Turbo – Larger than 88mm (98mm max)
Single Turbo 145mm max
Single Turbo (4cyl Production Engines Only)
Single Turbo (6cyl Production Engines Only)
Screw 98% max overdrive
B. Weight Additions / Deductions
All boosted Ford Modular Motors/Engines may deduct 100lbs from their original base weight.
All big block entries 585 cubic inches and smaller (Non 481X or Hemi) with a OEM bore space (4.84 Chevy, 4.900 Ford, and 4.800 Chrysler or smaller bore space) may deduct 100lbs from their original base weight. Cubic inch claims will be verified by P & G method.
Cast block with cast head combo may deduct 50lbs from their original base weight.
C. Small Block Engine
All entries using a small block engine have a maximum cubic inch size of 500 cubic inches. All engines 501 cubic inches and above will race in the big block category that their car fits.
D. Oil Retention Device
Mandatory – every car must have an oil retention device.
Any use of M3, M5, nitro-methane, polypropylene, and/or hydrazine are prohibited. Gasoline as defined by a mixture of hydrocarbons is permitted. The use of methanol fuel is for naturally-aspirated, turbocharged, and supercharged engine combinations. Methanol must be pure U.S. federal grades A or AA without the addition of additives, masking agents or any other substances. NPK Tech Dept reserves the right to check fuel at any time. Failure to pass fuel check is grounds for disallowance of the run and disqualification from the event during eliminations.
The maximum size for any and/or all entries using twin turbochargers is 98mm or 3.850 inches. Ported shroud inlets are prohibited. Map groove edge may not be more than 0.200 inches behind leading edge of compressor wheel. Map groove max width is 0.135 inches. Any type of reducer that decreases the inlet dimension, to lower class weight, is prohibited. Compressor wheel / impeller must only be constructed of cast or billet aluminum. Turbine wheels are only allowed to be constructed from Inconel material. Turbocharger size will be verified by one or both of the following methods:
1. By measuring the housing bore at the leading edge of the impeller wheel. The maximum diameter of the housing bore at the leading edge of the impeller wheel may not exceed 2mm more than the maximum allowable turbocharger size permitted in this class.
2. By measuring the impeller inducer wheel where the leading edge of the inducer wheel meets the housing. The wheel/blade contour from the inducer to the exducer must be continuous without steps.
The use of water, methanol or substance injection on any boosted vehicle is prohibited. Nitrous plates, bottles, solenoids or lines are not permitted on any vehicle unless nitrous is the sole power adder.
All nitrous bottles must be securely mounted and be safety vented with pop off to outside of the vehicle. The use of external flame type device for heating of bottles is strictly prohibited. Any use of nitrous in non-nitrous combinations is strictly prohibited. (example: shifter, waste gates, parachute systems, etc.)
Intercoolers are only allowed on centrifugal and turbocharged entries. Air-to-Air or Air-to-Water intercoolers are the only intercoolers permitted for gasoline powered entries. Air, water and ice are the only allowed substances in the intercoolers or the intercooler reservoirs. The use of any other agents is prohibited.
Any transmission, torque convertor, and clutch permitted. Direct drives are prohibited. Driveshaft meeting SFI 43.1 spec is required.
All vehicles must have a chassis that meets the guidelines set by SFI for their respective speed and elapsed time. A valid NHRA serialized chassis certification sticker is mandatory at an NHRA Member Track. NHRA license and chassis cert is accepted at ALL event locations. Minimum ground clearance is 3” from forward nose to 12” behind front spindles, including front exit style headers.
Body must maintain an overall OEM factory style and appearance for year, make and model being claimed. Aftermarket front ends are permitted but must maintain an overall factory style, appearance and proportions.
Front end external EXTENDER is permitted to achieve 47” overhang measured from center of spindle to front edge of external extender or front facia/bumper. Extended front ends that do not have factory style, appearance or proportions will be scrutinized and must be pre approved by NPK rules committee.
Pro Mod style bodies, Top Sportsman style bodies, and heavily modified bodies that are modified in a drastic and visually perceptible manner for aesthetics, improved aerodynamics (example: sloped noses,laid back windshields) and/or wheel base advantage and do not have an external outwardly appearance of a factory stock model, will NOT be allowed to participate. (to be determined by Racemaster in consultation with Producer, NPK rules committee and compliance consultant).
All entries must be self-starting from inside the vehicle.
M. Master Cut-off Switch
An operational master cut-off switch is mandatory.
N. Tow Vehicles
The use of tow vehicles is permitted.
O. Crew Members
Each crew member must have the proper starting line credentials.
P. Driver Safety Restraints
When in the vehicle, from the ready line until the vehicle is safely stopped on the return road, the Participant driver is required to have and wear all industry standard and compliable safety restraint systems (including the helmet), which will be securely fastened in the vehicle at all times.
A valid state or government issued driver’s license beyond a learners permit is mandatory for cars running 10.00 (6.40) or slower. A valid NHRA competition license is mandatory for cars running 9.99 (6.39) or quicker.
R. NHRA Note:
It is the Participant’s responsibility to familiarize themselves with the No Prep Kings class requirements as well as all NHRA safety requirements and general regulations. The Participant agrees they bear the ultimate responsibility when it comes to safety and how the Participant and the vehicle comply with the NHRA rule book. The Participant also agrees that no one else other than the Participant is in the best position to know about how their particular race vehicle has been constructed and how to safely operate it.
T. Repairs or Construction of Vehicles
Before proceeding with any builds or changes that do not fit within the exact guidelines of the NPK rules or are in a “gray area”, please submit proposed changes to NPK Rules Committee for approval.
REMINDER – Breaking the Tournament Rules will result in loss of points and/or permanent disbarment from No Prep Kings Series.
Note – These vehicle guidelines are an excerpt of the overall Tournament Rules and are being provided for informational purposes only. In the event a 2019 tournament takes place, other terms and conditions shall apply. In order to be considered for any future No Prep Kings Series invitational, vehicles should adhere to these guidelines.