LIMITED STREET 235 SHOOTOUT CLASS
RULES & REGULATIONS
Updated: Feb. 16, 2021
Limited Street 235 is a heads-up small
tire class designed for American
production vehicles. Small block and
big block engines are allowed the use
of a single power adder which is
restricted in size to maintain class
parity. Cross breeding of an engine to
a different make/manufacturer body is
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
This class will be an all run heads-up
field, 1/8 mile, NHRA Pro Style Ladder
on a .400 Pro Tree.
ENGINE POWER ADDER BASE CID – (WEIGHT)
SB naturally aspirated inline – 2600/
2700 non inline
BB NA 3000 (+100 lbs. for big chief
4cyl VW 1600
SB nitrous - 8.2 deck or modular 2950
SB nitrous - 2950 cylinder head add
see bottom for additional weights
BB nitrous 3250
BOP Mopar 3150
SB cast turbo - 3200
6 Cyl turbo – 3175
6 Cyl any listed supercharged/Blower –
SB D1, NOVI 2000, Kenny Bell 3.6 –
SB 6-71 3100
SB V7/V30 JTB Trim 3125
SB D1x 3250
SB YSI cast – 3250
4cyl turbo manual trans 2025
4cyl turbo auto trans 2225
Inline 6 turbo manual trans 2900
Inline 6 turbo auto trans 3100
Twin 71 mm turbo full size car with
bench seat 4000 lbs
– Maximum CID for all small block N/A
entries is 480 inches. (Add 7lbs per
cu in over 470 up to 480 cu in.)
– Maximum CID for all small block
Boosted entries is 440 inches.
– Maximum CID for all small block
Nitrous entries is 465 inches.
– Maximum CID for all Big Block
Naturally Aspirated combos is 632
– Maximum CID for big block Nitrous
entries is 588 inches. (Deduct 50 lbs.
for 540 and under)
– Maximum CID for Buick, Olds,
Pontiac, Mopar Nitrous combinations is
– Buick, Olds, Pontiac, Mopar
combinations are permitted
Blower/Boosted applications. Blower
combo will be 440 cu in with blow
thru, belt, and E85 (3200 lbs)
– Any engine in question will be
measured with a P&G gauge. A
correction factor of 1.5% will be
used. Competitors may be asked to
remove a cylinder head for bore and
stroke measurements should any
– All weights will be rounded down to
the nearest 5lb. increment.
- Add 25 lbs. for Holly High Ram or
equivalent on power adder SBF/SBC/LS
-Add 25 lbs. for a nitrous controller
-Add 50 lbs. for a boost controller
-Add 50 lbs. for gear drive
-Add 50lbs for BBF A head
-Add 50lbs for All* SB High port, Ford
TFS-R, TFS High port
-Add 50lbs. for class spec 76/105
billet 96/88 Turbine NEW
-Add 50lbs. for W5 Mopar head on
-Add 75 lbs. for All SB Nitrous 20
degree high port SR20 –FT1 or T1RI or
equivalent, 15* SBF and SBC Nitrous
18* and 23* raised runner heads. No
turbo/ supercharger combos with these
With all the new heads that are coming
out, we will look at them and adjust
-Add 200 lbs. Ultra Cast Turbo 76 x
116 - 96 x 88
Deduct 50lbs for 235 S/S radial (any
combo can take weight break)
Deduct 50lbs for SBC and SBF Stock
Deduct 50lbs.for Mod and LS Stock iron
Deduct 50 lbs. Stock 7.4L/9.8 deck and
smaller factory block
Deduct 50lbs for 6AL or equivalent box
with no add on.
Deduct 50lbs. for non-intercooled
boosted/blown combos only
REQUIREMENTS & SPECIFICATIONS
Any aftermarket cast iron or cast
aluminum block permitted. All blocks
are restricted to factory OEM bore
spacing for brand being used. LSX
block bolt pattern is permitted for LS
based engines. World Products
Man-O-War bolt pattern is permitted
for small block Ford engines.
All entries are permitted to bush
lifter bores. Billet Blocks
SB Power Adder Limited to 440 cubic
inch (NA permitted up to 470 cubic
inch at 1.5 lbs. added over 440)
BB NA Limited to 620 cu in (over 572
add +3 lbs. per cubic inch up to 600
add 3.5 601-620)
BB NOS to 588 (over 572 add +3 lbs.
Per cubic inch up to 588.) (Includes
BOP – Mopar entry)
SFI Spec 18.1 balancer is required.
ENGINE MOUNTS & LOCATION
Engine/motor plates and mid-plates are
permitted. Engine block and cylinder
heads cannot be in contact with the
Factory OEM or aftermarket cast iron
or aluminum cylinder heads are
permitted. Billet and one-off
fabricated heads are prohibited. All
cylinder heads must maintain factory
OEM bolt pattern for head and intake
manifold bolts of manufacturer brand
being used. Porting is permitted. All
cylinder heads must maintain factory
OEM valve angles of +/- 2 degrees. The
Event Tech Director reserves the right
to check valve angle either on or off
NA BB permitted Big Chief/Big Duke
style and Ford C head.
NA SB permitted any cast cylinder head
with prior approval.
Power Adder cylinder heads for SB
limited to, 23 degree Chevrolet, 15
degree LS, 18 degree Mopar, 20 degree
Ford, OEM Ford casting 4v Modular, any
2v Modular, Trick Flow Twisted Wedge
and LS 13.5 OK
All cylinder heads must maintain the
automobile OEM intake manifold bolt
Nitrous Big blocks limited to stock
valve angle/stock port layout/no
Note: Stock factory OEM heads are
those cylinder heads that are factory
production line installed on
production vehicles as recognized by
Inline non stock valve angle not
permitted on boosted combos
Any splayed or canted valve
(non-inline) head not permitted on
Any aftermarket, commercially
available, mass produced, single
carburetor, 4150 or 4500 series, cast
intake manifold permitted. Modified
opening cast tunnel ram intake
manifolds are permitted for Small
Block & BB N/A combinations only.
Porting is permitted. Cast Holley EFI
ram intake or similar short ram
permitted on SBF/SBC/LS boosted
combinations only. See note in
All entries are permitted to use any
conventional single stage plate system
or any conventional single stage
fogger system. The use of water
injection is permitted. The use of a
plate system with a fogger system is
prohibited. Nitrous push systems are
prohibited. The use of agents other
than nitrous oxide as part of, or
mixed in, the system is prohibited.
All entries must use only gasoline for
the fuel enrichment circuit. All
nitrous jets must be as-supplied,
un-modified from the manufacturer and
must be a concentric circle. No other
shapes such as ovals, diamonds, etc…
permitted. All entries are permitted
to use a maximum of two 10lb nitrous
bottles or a single 15lb nitrous
bottle. Any method of cooling the
nitrous bottle inside the vehicle is
strictly prohibited. Bottle
temperatures will be randomly checked
before and/or after a run. If the
bottle temperature is found to be
colder than 65 degrees, the run will
Plate System: Any conventional single
stage or cross-bar single stage plate
nitrous system with a maximum of four
spray bars (two nitrous & two fuel)
Big Block Nitrous entries maximum
1 jet .088
2 jets .062
8 jets .030
Small Block Nitrous/BOP Mopar entries
1 jet .098
2 jets .073
8 jets .036
Small Block Nitrous entries maximum
(8.2 Deck/2V mod motor ONLY!!!)
1 jet .104
2 jet .078
8 jet .040
Progressive systems are permitted. If
you are claiming NO PROGRESSIVE all
grounds and wiring must be traceable
Purge System: Nitrous purge systems
are permitted a maximum of 1 solenoid.
Progressive systems are permitted to
use one inline ‘’safety’’ solenoid.
Purge line must clearly exit the
hood/cowl or body in a fashion to not
allow purged nitrous to enter the
engine when racing.
Nitrous Lines: All entries are
required to have one continuous -8
maximum (Plate System) and -8 maximum
(Fogger System) uninterrupted (no
coiling) nitrous supply line from the
nitrous bottle to the engine. Maximum
length of nitrous supply line from
nitrous bottle to nitrous supply
solenoid is 15ft. The line from the
valve to the engine cannot store/hold
nitrous oxide when the system is not
Centrifugal superchargers are limited
to the following dimensions: Maximum
impeller inducer diameter of 3.70
inches. Supercharger impeller must be
constructed from aluminum. Centrifugal
superchargers are permitted to use any
gear drive or transmission system,
including the Vortech V30 series.
Maximum supercharger sizes D1, V-7/V30
JTB Trim, NOVI 2000, Kenny Bell 3.6,
Roots 6-71 blowers must be off the
shelf street style – B&M type/TBS) Sb
w/ single carb on gas only.
Max cast turbo size 76mm measured tip
to tip. Compressor inducer will not
exceed 76 mm Compressor Exducer will
not exceed 102 mm Turbine will be 96
mm X 88 mm. The Borg Warner S400SX4
S475 1.32 a/r with T6 flange fits into
Forced Inductions carries our SPEC
class spec 76/105 billet 96/88 Turbine
unit. (preferred part)
(No reducers allowed to achieve this
size and no clipped wheels)
V6 and 4cyl permitted billet wheel.
(see additional notes below)
You may be required at any time to
remove your turbo and/or your turbo
cover to be checked.
If you are claiming NO BOOST
CONTROLLER: A single line from the
manifold to the wastegate only
Nothing else to top of wastegate or
blow off valve
Air-to-water intercoolers are
permitted for supercharged and
turbocharged entries only. Only one
intercooler is permitted for all
Meth injection permitted on Nitrous
combos only. Any use of
nozzle/injector in any engine
combination forward of throttle body/
carburetor is strictly prohibited. All
injectors on boosted combos must be
directly mounted to the intake
Any Oil System permitted. Any oil
pump, vacuum pump, and oil pan
permitted. All entries are required to
use an oil retention device. Device
can be either a ballistic style
blanket or a custom built metal pan.
Metal pan must extend from the
engine/motor plate rearward to the
back of the engine. Metal pan must fit
inside the frame rails and be 3 inches
above the ground.
Any cooling system permitted.
Radiators are not required.
Any exhaust system permitted. All
exhaust systems must be directed out
of body and away from driver and fuel
tank. Exhaust may exit underneath car
or out the front fenders but must not
affect timing or staging beams. Bull
horns prohibited. Zoomies prohibited.
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.
Fuel injector size and or type are
Any single aftermarket throttle body
permitted NA. 4150 or 4500 for power
Maximum carburetor size for all power
adder entries is a single 4500-style
or a Pro-Systems 115mm SV1.
Throttle control must be operated by
the driver’s foot.
VP Racing Fuels Gasoline, Q16, C-85,
E-85, C12, 16, 23, 25, 45, or NO2 are
the only fuels permitted. 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. M1 and M5 prohibited.
CLUTCH, FLYWHEEL & FLYWHEEL SHIELD
Flywheel and clutch meeting SFI Spec
1.2, 1.3, 1.4, or 1.5 is mandatory.
Clutches are limited to a dual disc
maximum. Flywheel shield meeting SFI
Spec 6.2 or 6.3 is mandatory. Clutch
must be manually operated by the
driver’s foot. Electronics,
pneumatics, hydraulics, or any other
device may in no way affect the clutch
system. The throw-out bearing must
release all fingers, levers, stages,
etc. simultaneously. Staged or
variable release clutches are
OEM or aftermarket transmissions with
a maximum of 5 forward speeds
permitted on N/A combinations only.
Clutchless models permitted. Any gear
change must occur from direct action
by the driver. Pneumatic, electric,
hydraulic, etc. shifters prohibited.
Torque converter not permitted with
this type of transmission. Manual
transmissions must utilize SFI
approved bell housing.
Any OEM or aftermarket automatic
transmission is permitted. Lock-up
style transmission and/or torque
convertors are prohibited unless OEM
equipped (i.e. A.O.D.). The use of
transmission-to-engine adaptors is
permitted. The use of trans-brakes is
permitted. Pneumatic, electric,
hydraulic, etc. shifters permitted.
Any American production type steering
Aftermarket stock-type shocks/struts
permitted. Rear coil-over shocks are
Factory type front suspension only.
Coil over shocks are allowed.
Aftermarket replacement control arms
are allowed. Aftermarket
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.
Stock-type and ladder bar rear
suspension systems are permitted.
The use of wheelie bars is prohibited.
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 radiator
support 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
Entries must retain stock wheelbase
dimensions of + or – 1 inch. Maximum
wheelbase variation from left to right
is 1 inch.
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
Any 235/60 or 26 x 8.5 bias or radial
deduct 50 lbs. for 235 S/S tire
Aftermarket racing wheels permitted.
Interior must maintain a factory
upholstered appearance. OEM dash board
is required and can be made of
fiberglass or carbon fiber. 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.
Aftermarket steering columns and
steering wheels are permitted.
PEDALS & PEDAL LOCATION
Stock type pedals/linkage is required.
Body must retain original appearances
and profiles for year being used. OEM
body shell must be intact. Light
weight body panels are restricted to
hood, fenders, bumpers, doors and
deck-lid/truck-lid or hatch. Composite
roof panels are permitted on 2005 and
newer vehicles. Hood and
deck-lid/trunk-lid must be hinged or
lift off style. All front ends must be
of factory dimensions and cannot be
lengthened. No extenders permitted.
Alterations or aerodynamic
modifications are prohibited. Body
must be finished or painted. Pre- 1964
body style will receive -25 deduction
The use of aftermarket forward facing
hood scoops is permitted on NA. The
use of cowl induction style hoods are
allowed on any vehicle with a maximum
height of halfway point of windshield.
OEM cowl is required and modifications
Grille must maintain a "professional
appearance" for year, make and model
Stock, factory firewall 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.
RADIATOR CORE SUPPORT
Radiator core support is not required.
FENDER SPLASH PANS
Fender splash pans may be altered.
WINDSHIELD & WINDOWS
OEM glass or NHRA approved Lexan is
Stock floor in stock location is
required under driver and passenger
seats. Flat area of floor-pan behind
seat area and rearward may be replaced
with a minimum of .024-inch thick
steel or .032-inch aluminum. All
entries are allowed a removable
Aftermarket style mini-tubs are
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/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 Limited
Street 235 Shootout 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 Limited Street
235 Shootout 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
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.
Battery may be relocated and must be
an automotive type.
Any battery-operated ignition system
permitted. Distributorless ignition
systems are limited to one coil per
cylinder only. Optical devices and
magneto ignitions are prohibited.
A master cutoff switch is mandatory on
all vehicles with a battery located in
Aftermarket starters, in stock
SUPPORT GROUPS: 9
BRACKET RACING AIDS
The use of any bracket racings aids
such as optical sensors, delay boxes,
shutter boxes, throttle stops, etc.
are prohibited. The use of any device
(electrical or mechanical) that allows
a driver to ascertain the position of
their vehicle to the starting line is
All pressurized bottles must meet
D.O.T. 1800lb minimum specification.
The use of tow vehicles is permitted.
The driver when in the vehicle, from
the ready line until the vehicle is
safely stopped on the return road, is
required to have all safety restraint
systems (including the helmet) on and
be securely fastened in the vehicle at
A Valid state or government issued
driver’s license beyond a learner/s
permit level is mandatory for cars
running 10.00 or slower. A valid NHRA
competition license is mandatory for
cars running 9.99 or quicker, at a
NHRA Member Track. A valid NHRA or an
IHRA competition license is mandatory
at an IHRA Member Track.
Note: It is ultimately the
competitor’s responsibility to
familiarize themselves with the
Limited Street 235 class requirements
as well as all NHRA safety
requirements. The competitor agrees
the ultimate responsibility when it
comes to safety and how it complies
with Ultra Street Class rules and NHRA
rule books. The competitor also agrees
that no one else other than the
competitor is in the best position to
know about how their particular race
car has been constructed and how to
safely operate it.
X275 Motorsports will reserve the
right to adjust the rules for parity
at any time. Any rules adjustment
request must be sent via email to: