275 Limited is a heads-up 1/8th mile class for any and all types
of Rear Wheel Driven Vehicles from Classic 50's Iron, 60's Muscle
Cars to Late Models Hot Rods & Trucks. This class is going to
feature limitations in Cubic Inch Displacement, Power Adders and all
cars will have to use a 275 or smaller Radial Tire or 28x10.5 or smaller
BODY / INTERIOR
BODY: The car must retain its original appearance, materials
and profiles. Aftermarket Fiberglass or Carbon Fiber Body Parts limited
to Hood, Deck-lid and Bumpers only. Rear Mini-Tubs or altering of
factory wheel tubs are permitted however no full size wheel tubs will
FIREWALL: Must retain factory unaltered firewall, in original
location. A cosmetic overlay is permitted.
FLOORBOARD: Must retain the factory Floorboard from Firewall
to beginning of Trunk/Hatch area... Trunk/Hatch/Spare Tire area can
be modified/flattened for battery placement, Fuel Cell etc..
GRILL / FRONT BUMPER: Factory Grille and Front Bumper must be
of original design with no alterations to allow additional Air-Inlets
HOOD: No Forward-Facing Hood Scoops of any design or Air-inlets
added for Blower/Turbo Cars
INTERIOR: Factory appearing door panels, carpet and dashboard
are required. Back seat may be deleted, but must have carpet covering
the bare floor.
SEAT & SEAT LOCATION: Two front full-size bucket seats,
or one bench seat with upholstery required. Seats must remain in the
factory location without. Nitrous Bottle, Ignition box or any other
device cannot be mounted within the passenger side seat.
WINDOWS: Must be factory OEM Glass, no Lexan permitted.... 1
exception, rear window on a truck if the roll-cage goes into the bed
CHASSIS / SUSPENSION
FRAME & CHASSIS: Stock frame rails must be retained in stock
locations front and rear, Notching of rear frame rails is allowed
(No Full Back Half Chassis Permitted) Sub frame connectors are permitted.
FRONT SUSPENSION: All cars must retain stock-type front suspension.
Aftermarket Tubular Control Arms, K-Member & Coil Over kits are
legal but must completely be a bolt-on conversion. Bolt-On Firewall
forward are not legal unless noted below**. Replacement Bolt-on Lightweight
K-Members are legal, but must be a direct bolt on, no welding modifications
permitted. Stock wheelbase will be enforced on all vehicles.
REAR SUSPENSION: After-Market Control Arms, Bushings, Shocks, Leaf
Springs, Torque Arm & Coil Springs are OK to upgrade as long as
all Factory/OEM Suspension Attaching Points are utilized in the way
they came from the vehicle manufacturer with the following exception:
On Mini-Tub or vehicles with Leaf springs moved inward, Shocks must
still follow the same angle and placement as factory equipped (so
if the bottom bracket is moved in 2" the top must do the same)
Bolt On Traction/Slapper Bars are allowed.
Rear Coil over Conversions are allowed with a 100lb weight penalty.
WHEEL BASE: Must retain stock wheel base with a maximum variation
right to left and front to back of one inch.
WHEELIE BARS: Wheelie bars are strictly prohibited and not permitted.
AUTOMATIC TRANSMISSIONS: Any OEM automatic transmission permitted.
Aftermarket torque converter, shift kit, valve body, shifter, and
pan cooler use are permitted. Trans brakes are permitted.
MANUAL TRANSMISSION: After-market Standard Manual Transmissions
are allowed except for Clutchless-Types, Clutch/Automatics or Planetary
Transmissions. All shifts must be made manually without the aid of
electric, hydraulic or pneumatic devices.
ENGINE / ELECTRICAL
BRACKET RACING AIDS: The use of bracket racing aids such as
optical sensors, delay boxes, and throttle stops are prohibited
ENGINE: 515ci Limit for Power Adder Big Blocks - 525ci Limit
for NA Big Blocks - 444ci Limit for Nitrous and NA Small Blocks -
410ci for Boosted Small Block (See Weight Breaks)
ENGINE BLOCK: Aftermarket Cast Iron are allowed. (No After-Market
Aluminum or Billet Blocks permitted)
ENGINE MOUNT LOCATION: Engine must remain in factory stock OEM
location. Engine may not touch the factory unaltered firewall. Motor
plates are permitted.
OILING SYSTEM: No Restrictions. The front cross member may be
altered for oil pan removal. Vacuum pumps are acceptable.
ON BOARD DIAGNOSTICS / DATA RECORDERS:
On board diagnostic computers and recorders are permitted. Memory
and playback tachometers are allowed.
STREET LEGAL REQUIREMENTS: All cars are required to have Left
& Right working headlights and tail lights
TRACTION CONTROL: Strictly Prohibited... Vehicle is limited
to the use of a single drive-line sensor that is capable of measuring
RPM and/or Wheel Speed. Sensor wiring must be clearly identified and
easily traceable from sensor connection to Data Acquisition system.
Sensor cannot be spliced or have any jumpers installed under any circumstances.
RPM sensor CANNOT be routed into any Engine Management/Timing Management
system, be it via direct or indirect connection. Driveline will be
checked in Tech and Random checks will be made during race weekends...
If you are caught violating these rules, Car & Driver will be
suspended from future Events
INDUCTION - EXHAUST
CARB: Any 4150 Based of Conventional design 4-Barrel is Max
permitted (no 4500 Series/Dominators allowed on a power adder combo)
EFI: Any EFI system is permitted but throttle body is limited
to 92mm or a 4150 Series 4-Barrel
FUEL: Gasoline (Race Gas) and E-85 are the only legal fuels
CYLINDER HEADS: (See section under weight adds)
INTAKE (POWER ADDERS): 4150 flange as-cast aluminum of conventional
1-piece design (non Tunnel-Ram) Intake Manifold. Intake must have
a visible part number from the manufacture to prove its of 4150 design.
Porting is allowed but intake cannot be cut-up, welded-on or altered
in any way from its original design. If you're not sure, please email
us at email@example.com with your questions
LS/LSX Legal Composite Intakes: FAST 54039, 146302 / Weiand 5000 /
Professional Products Typhoon
INTAKE (Naturally Aspirated):
4150 or 4500 flange cast aluminum (Unless listed below) of conventional
1-piece design (non Tunnel-Ram) Intake Manifold. If you're not sure,
please email us at firstname.lastname@example.org with your questions. 4500
Intake and or 4500 Series Carb add 200lbs
MUFFLERS: REAL Production Mufflers are required all 275 Limited cars,
no Collector Mufflers permitted unless a Real Muffler is also in place.
Modification or removal of muffler internals is prohibited (no gutting).
If you're not sure what a "REAL MUFFLER" is (at least 6"
of the muffler "Main Body" is required)
INTERCOOLER: Air to Air legal with a 25lb weight Deduct. Air
to Water legal but complete system must be mounted from the firewall
(engine side) forward... This includes everything including Intercooler,
tank, lines, etc.
NITROUS: Any 4150 Nitrous Plate is legal, but cannot be used
with any other power adder and with the following restrictions.
*Only one (1) 10lb Nitrous Bottle is permitted
*Only one (1) -4 Nitrous Bottle line to Solenoid is permitted
*Only one (1) .125" MAX Orifice Size Nitrous Solenoid is permitted
*Only one (1) Fuel Solenoid is permitted
*Only one (1) Small Purge Solenoid Permitted (Purge plume must be
entirely outside of the engine bay and directed upward)
SUPERCHARGER-SMALL BLOCK ONLY: 10-Rib Max Belt (No Cog or Direct
LEVEL 1 (3200lbs) VORTECH: V3-SCI, V2-S, V2-SC, V2-SCI, V1-S, V1-SC
& V1-SCI / ProCharger: PB600B, P1iSC, P-1SC-1 & P-1SC-2
LEVEL 2 (3300lbs) VORTECH: V3-SI, V2-SI, V2-E & V2-SCI / ProCharger:
D1 & D1SC / KenneBell: 2.6
LEVEL 3 (3400lbs) VORTECH: V2-Ti, V1-Ti / ProCharger: F1, F1A &
F1D / KenneBell: 2.8 & 2.8LC / Paxton: Novi-2000
LEVEL 4 (3500lbs) VORTECH: V7-J, V7-JT, V7-YSi & V2-7YSi/ ProCharger:
F1A-91, F1A-94 / KenneBell: 3.6LC
ACCEPTED SINGLE "Non-Billet Wheel" TURBOCHARGER: 76mm with
the following guidelines: