1,000.00 RUNNER UP
X275 Drag Radial 2019 1/8/18
X275 is a heads-up class designed for small tire,
single power adder small block and big block
engine combinations to compete on the eighth mile.
Centrifugal Superchargers, Turbochargers and
Nitrous Combinations are restricted to specific
dimensions/sizes to ensure overall class parity.
All entries have the option to run either a 275
drag radial tire or 28inch by 10.6inch bias slick
on any type of rear suspension.
Note: This set of class rules is presented to all
competitors under the assumption that any
modifications not specifically written within
these rules shall be deemed illegal, unless the
competitor has the expressed written consent from
the Event Tech Director.
This class will be a 32 car field, heads-up - Pro
Style Ladder on a .400 Pro Tree
ENGINE POWER ADDER BASE CID BASE WEIGHT
6 Cylinder diesel (Cummins) Turbo 88mm 431 3200
6 Cylinder/4 Cylinder Turbo 88mm 431 2800 Turbo
80mm 2750 (no add or deducts)
Small Block Nitrous 500 cu in 2500
Small Block Supercharger max 4.025” Inlet 480 cu
Small Block Supercharger max 4.200”Inlet 480 cu in
Small Block Roots Supercharger 871 (on M1 with
billet head or block) 3100
Small Block Turbo 80mm 480 2825
Small Block Turbo 85mm 480 3075
Small Block Turbo 88mm 480 3125
Big Block Naturally Aspirated 750 2600
Big Block Conventional Head Nitrous up to 588 2875
Big Block Un-Conventional Head Nitrous up to 588
Big Block Conventional Head Nitrous 589-610 2975
Big Block Conventional Head Nitrous 611 to 650
Big Block Un-Conventional Head Nitrous up to 650
Base weights are set with gasoline as fuel
Maximum CID for all small block boosted entries is
Maximum CID for all small block nitrous entries is
Maximum CID for 4.84/4.90 nitrous big block
entries is 650 inches (add 2.5lbs per cubic inch
over 632 for nitrous combos)
Maximum Deck Height for all small block
combinations is 10.000 inches.
Maximum Deck Height for GM Big Block combinations
is 10.200 inches.
Maximum Deck Height for Ford Big Block
Combinations is 10.300 inches.
Maximum Deck Height for Mopar Big Block
Combinations is 10.700 inches.
6cyl/4cyl combinations are permitted intercooler
and Nitrous with gasoline as fuel.
(Prohibited with M1 as fuel)
Boosted diesel combinations may only use nitrous
oxide as a second power adder.
Add 100lbs for M1 with Turbocharger (intercooler
not permitted with M1)
Add 50lbs for M1 with Supercharger (intercooler
not permitted with M1)
Add 50lbs for any combination using a lockup
transmission/convertor. (No adder for N/A - SB NOS
combinations – prohibited on supercharged roots
Add 50lbs. for billet head (must be used with cast
block only of stock bore space)
Add 50lbs. for billet block (must be used with
cast head only and be stock bore space)
Add 50lbs. for SR20 or equivalent BB cylinder head
must maintain 20 deg. Valve Angle and conventional
Add 50lbs for any turbocharger with 141mm exducer
tip to tip and 133 exducer back plate measurement.
(Except on 6cyl, 8.2 deck and mod motor)
Add 50lbs for 4 link rear suspension – * see rear
suspension notes Add 25lbs. for E85
Deduct 25lbs for any SB Nitrous combination using
inline non-stock valve angle 12deg to 18deg
Deduct 50lbs for cast iron small block Chevrolet
or LS with stock deck height.
Deduct 50lbs for IRS
Deduct 50lbs for belt driven centrifugal
Deduct 50lbs. 3.70 inducer diameter centrifugal
supercharger (from 4.025 base weight)
Deduct 50lbs for NA/NOS combinations using a 4150
carb/throttle body/25lbs deduct for boosted combo
Deduct 50lbs for any SB Nitrous combination using
RR Stock Valve Angle (23*GM, 20* Ford, 18* Mopar,
or any square port 15*LS)
Deduct 50lbs for any SB boosted combination using
inline 12deg or down cylinder heads
Deduct 75lbs for any SB boosted combinations using
13deg to 15deg inline square port heads or Stock
Valve Angle (23* GM, 20* Ford, 18* Mopar) Raised
Deduct 100lbs. 4.10 inducer diameter centrifugal
supercharger (from 4.200 base weight)
Deduct 125lbs. GTX55-85 GTX55-88 GEN 1 (118 mm
compressor exducer back-plate)
Deduct 100lbs. any plate nitrous system
Deduct 100lbs. SB Nitrous and SB boosted entries
using cathedral port LS - 13.5/15 degree or Stock
Valve Angle 23*GM, 20*Ford, or 18*Mopar non raised
runner inline valve heads.
Deduct 100lbs for any Ford Modular combinations,
8.2 deck height combinations or 365cid or smaller
pushrod combinations using billet block. (Coyote
Deduct 200lbs for any Ford Modular engine
combinations, 8.2 deck height combinations or 365
Cubic inch or smaller pushrod combinations
REQUIREMENTS & SPECIFICATIONS
Any aftermarket cast iron or aluminum engine block
permitted. Billet engine blocks are permitted.
Billet blocks are only permitted to be used with
cast cylinder heads. The use of billet cylinder
heads on billet blocks is prohibited. Factory OEM
bore spacing for particular engine brand being
used is required for all entries. Diesel combo
SFI Spec 18.1 balancer is required.
ENGINE MOUNTS & LOCATION
Engine block and cylinder heads cannot be in
contact with the firewall.
Any aftermarket cylinder head is permitted. Small
block entries are permitted to use billet cylinder
heads. Billet cylinder heads are only permitted to
be used with cast engine blocks. The use of billet
cylinder heads with billet blocks is prohibited.
Big block entries are permitted to run any cast
conventional and unconventional style heads. Twin
spark plugs per cylinder are permitted for Factory
OEM applications (Gen III Hemi). Diesel combo
Any intake manifold is permitted. Except on Big
Block conventional or Big Block unconventional
stock bore space, nitrous combos. (A commercially
available, mass produced, cast aluminum intake
manifold is required).
Small Block Entries: Allowed to use any
Big Block Entries: Allowed to use any single-stage
system with a maximum of one nozzle per intake
Big Block & Small block nitrous are permitted
water/meth injection. All EFI Big Blocks will only
be allowed 2 nitrous solenoids for a dry nitrous
system and will only have 1 line per nozzle/per
cylinder. (Using both sides of the fogger nozzle
on a dry EFI NOS BB combo is prohibited (Cold
Centrifugal superchargers are allowed a maximum
impeller inducer diameter of 4.200 inches with a
maximum air inlet outside diameter of 5.00 inches.
Supercharger impeller must only be constructed of
cast or billet aluminum. Supercharger is permitted
a fresh air source from either the front bumper or
grille area of the vehicle.
Single turbocharger limited to 88mm maximum.
*Garrett GTX GEN II/PTE XPR (using current X275
exhaust/turbine measurements) permitted with
weight penalty. Turbocharger size will be verified
by measuring the housing bore at the leading edge
of the impeller wheel and must maintain the
contour of the compressor housing. (Stepped
compressor wheel prohibited) Inducer dimensions
may not exceed 80.9/85.9mm/88.9mm and Exducer
backing plate and blade tip to tip dimensions may
not exceed 133mm on MID FRAME turbos except where
noted. *The Garrett GTX GEN II/PTE XPR Inducer
dimensions may not exceed 85.9mm/88.9mm, Exducer
backing plate dimensions may not exceed 133mm. The
Exducer tip to tip measurements may not exceed
142.5mm. On LARGE FRAME turbos the inducer may not
exceed 85.9/88.9mm and Exducer dimensions may not
exceed 141.224mm. The maximum diameter of the
housing bore at the leading edge of the wheel may
not exceed 2 mm more than the maximum allowable
turbocharger size permitted. Inserts or reducers
to achieve inlet or outlet dimensions prohibited.
Compressor map groove will not exceed .250 of an
inch. Any turbocharger entry may be asked to
remove the compressor cover and/or turbine housing
for inspection. The turbine wheel may not exceed
113mm X 103mm on ANY turbocharger. Turbine wheels
are only allowed to be constructed of Inconel
material. Billet aluminum compressor
wheel/impeller permitted. Any inconsistent
modifications to compressor or turbine wheel,
blades, hubs, cover, or housing, beyond accepted
commercially available manufacturing process, is
All boosted gasoline, diesel or E85 entries are
permitted to use one intercooler. Intercoolers can
either be air-to-air or air-to-water. Water and/or
ice are the only agents allowed to be used with
intercoolers. The use of any other agent to assist
in the cooling of discharge and/or inlet air for
boosted applications is prohibited. Use of
intercooler with M1 (Alcohol) is prohibited
(except on 6cyl/4cyl with M1).
Meth injection permitted. The use of a single
nozzle/injector in any engine combination forward
of throttle body/carburetor in the charge tube is
permitted but must be within 6 inches of throttle
body or carburetor and must supplied fuel directly
from intake mounted fuel rail (diesel combo
permitted stand-alone fuel supply).
OIL RETENTION DEVICE
All entries are required to have an oil retention
device. The device can either be a custom built
ballistic blanket or a ‘’belly’’ style pan.
Any cooling system permitted. Radiators are not
Any exhaust system permitted. Exhaust may exit
underneath car or out the front fenders but must
not affect timing or staging beams.
Any electronic, mechanical or belt driven fuel
pumps are allowed. Electronic fuel pumps must shut
off with the master electric cut-off switch. Fuel
cell must have a pressure cap and be vented to the
outside of the body. Front mounted fuel cells must
meet SFI Spec 28.1 and be mounted between the
frame rails or enclosed in a round tube frame. A
round tube frame must be constructed of a minimum
of 1 ¼-inch O.D. x .065-inch chrome moly tubing.
Artificial cooling or heating of fuel (i.e., cool
cans, ice, Freon, etc.) prohibited. Circulating
systems that are not part of the normal fuel pump
system are prohibited.
Any aftermarket electronic or mechanical fuel
injection may be used.
Any aftermarket throttle body permitted. Nitrous
and Boosted applications are limited to a single
throttle body and N/A entries are permitted two.
Aftermarket carburetor is permitted. Spread or
Split carburetor is permitted.
Throttle control must be operated by the driver’s
VP Racing Fuels Gasoline, M1, C-85, and E-85 are
the only fuels permitted. Diesel combinations must
use VP Racing Fuels Torque Diesel (Car must be
equipped with fuel sample valve). Event Tech
Director reserves the right to inspect fuel at any
time during competition Failure to pass Fuel Check
is grounds for disallowance of the run during
competition and disqualification from the event
during eliminations. Fuel is checked using various
means. Samples given to Fuel Check Technical
Inspectors are compared to data taken from known
fuel samples provided by VP, adjusted for
temperature, and within a tolerance determined by
Event Tech Director. Failure occurs when the
sample readings fall outside those tolerances.
CLUTCH, FLWHEEL & FLYWHEEL SHIELD
Clutch and flywheel meeting SFI Spec 1.1 or 1.2 up
to a twin-disc maximum is mandatory. Steel
flywheel shield meeting SFI Spec 6.1 is mandatory.
Flywheel shield cannot be modified for clutch
adjustment and/or cooling holes
Aftermarket transmissions with a maximum of 5
forward speeds are permitted. Clutchless
transmissions are permitted. All gear changes must
be a direct action of the driver. Pneumatic,
electric, hydraulic, etc. shifters are prohibited.
Any OEM or aftermarket automatic transmission is
permitted. Lockup convertors permitted.
Trans-brakes are permitted. Pneumatic, electric,
hydraulic, etc. shifters are permitted. Bruno
converter style transmission prohibited
Any steel, aluminum or carbon fiber driveshaft
meeting SFI 43.1 spec is required.
Any automotive type rear-end is permitted.
BRAKES, STEERING & SUSPENSION: 3
Front and rear hydraulic brakes are required.
Automated brakes are prohibited. The application
and release of the brakes must be a function of
the driver. Dual reservoir master cylinder is
required. Line-lock is permitted only on the front
wheels using one line-lock button and solenoid.
Any other electrical, pneumatic, hydraulic, etc.
switch in braking system is prohibited.
Any American production type steering system
Aftermarket stock-type shocks/struts permitted.
Factory type front suspension only. Coil over
shocks are allowed. Aftermarket replacement
control arms are allowed. Aftermarket
K-Members/Commercially available sub-Frames
allowed. (Must have prior approval from tech)
Strut towers must be in factory location with
factory sheet metal attaching factory frame rail
to top of strut tower, can be notched, windowed,
or trimmed for header clearance but must maintain
factory sheet-metal attachment.
Pre-1978 and Older Vehicles: The use of
aftermarket bolt-on front suspension kits for
engine fitment is permitted. Factory strut/shock
towers are optional in pre-1978 vehicles using an
aftermarket bolt-on front suspension kit.
Stock-type, ladder bar, and OEM COPO/Drag
Pak/Cobra Jet suspension systems are permitted.
NHRA SS GT/Super Mod FWD conversion keeping rear
frame rail permitted. 4 link permitted on SB NOS
Combo without penalty.(* NMRA/NMCA 2018
competitors with 4 link will be grandfathered in)
*see weight add
The use of wheelie bars is not permitted.
All vehicles must have a chassis that meets the
guidelines set by SFI for their respective speed
and elapsed time. A valid NHRA serialized sticker
is mandatory at an NHRA Member Track.
Stock frame required from the front engine/motor
plate to the back of the rear wheel tub.
Back-halved cars are prohibited. Front and rear
sub frames may be joined together. Horizontal and
vertical notching of rear frame rail is permitted
for tire/rear end clearance.
All entries must maintain a wheelbase of +/- 1inch
from OEM specifications.
A minimum of 3 inches from the front of the
vehicle to 12 inches behind front spindle
centerline is mandatory. A minimum of 2 inches for
the rest of the vehicle is mandatory (except for
oil pan and exhaust headers).
TIRES & WHEELS: 5
All entries have the choice to either use a
28-inch tall by 10.6-inch wide bias slick or a
275/60/15 or Pro Bracket drag radial tire. Tire
tread may not extend outside of the fender. Any
racing wheel permitted.
Interior must maintain a factory appearance. Any
aftermarket racing style seat is permitted.
Driver’s seat must be located in the stock
location. Passenger seat is not required. Door
panels are required. Floor and transmission tunnel
where visible must be carpeted or upholstered. .
All Vehicles must retain its original appearance,
profiles, and dimensions. Factory roof and quarter
panels must be used. 2005 and newer vehicles
permitted replacement roof panel. Aftermarket
fiberglass and/or carbon fiber replacement panels
are limited to hood, front fenders, doors,
deck-lids, and bumpers only. All front ends must
be of factory dimensions. Any beam tripping
devices forward of the bumper are prohibited.
(Track tech official will have final say) Stock
style appearing front and rear bumpers are
required. A hood must be used: scoop or hood must
cover the entire induction system. Forward facing
hood scoops/ turbo or supercharger inlets are
permitted. Alterations or aerodynamic
modifications are prohibited. Any
aftermarket/modified front bumper/valence must
have prior approval from the Event Tech Director
Forward facing hood scoops are permitted for
nitrous assisted entries and may not extend above
the roof line. Vehicles that are equipped with an
EFI system are not required to run a hood scoop.
Carburetors must be completely covered by the hood
or hood scoop. Sensors, transducers, vents,
wiring, hoses/lines, etc. are prohibited from
being inside the hood scoop.
All entries are required to have an OEM cowl area,
except 4th Gen GM F-body vehicles.
Factory Grille or facsimile (painted or decal)
Stock, factory firewall location is required.
Notching and smoothing of firewall is permitted
but must be identifiable as being in the factory
location. Factory OEM fiberglass firewalls
(Corvette) are permitted to replace the factory
firewall with a minimum of .024 thick steel
located in the factory location. No part of
mid-plate may attach or support the firewall.
FENDER SPLASH PANS
Fender splash pans may be altered.
WINDSHIELD & WINDOWS
All entries are permitted to use Lexan windows.
All entries are required to have stock floor pans
on both the driver’s side and passenger’s side of
vehicle. Transmission tunnel may be removable and
must be made of either .024 inch thick steel or
.032 inch thick aluminum. Removable floor panels
are prohibited. Patching permitted.
All entries all permitted to use steel, aluminum,
or carbon fiber wheel tubs.
All entries are permitted to use rear
wing/spoilers. Wing/spoilers are allowed a maximum
length of 26 inches. Any adjustments to the
wing/spoiler during a run are prohibited.
All entries must have operational headlights
and/or fog lights and taillights.
All cars in competition must be painted or
wrapped. Advertising graphics are permitted on the
body. In order to be eligible for the X275 points
championship program, all sponsors’ decals must be
easily visible and located on the outside of the
vehicle. Failure to do so can result in the driver
forfeiting all claimed championship points for
that particular event. The X275 points
championship program requires that all entries run
the following decals:
1. Championship Windshield Banner: Decal needs to
be located on the top of the windshield or just
above the windshield located on the body.
2. Championship Series License Plate: Plate must
be located on the front of the vehicle
3. Class Sponsor(s): Decal must be located on the
passenger’s side lower portion of the windshield.
4. Class & Competition Numbers: Numbers must be
easily visible/legible and located on the front,
back, and both side windows.
A maximum of two batteries is allowed.
Any battery operated ignition system and
distributor drive system is permitted.
All entries must be self-starting with an on-board
MASTER CUTOFF SWITCH
An operational master cutoff switch is mandatory.
SUPPORT GROUP: 9
Computer/data recorders are permitted and must
standalone and to be only used for information
BRACKET RACING AIDS
The use of any device (electrical or mechanical)
that allows a driver to ascertain the position of
their car on the track prohibited.
A maximum of one pressurized container (excluding
nitrous and fresh air systems) per vehicle is
permitted. All pressurized bottles must meet D.O.T.
1800lb minimum specification.
The use of tow vehicles is permitted.