This Page Last Updated:
November 30, 2017
Ultimate/Ultra 275 Street
Rules 2018 FINAL
1/8th mile Eliminator
Fiberglass/Carbon body panels are limited to hood,
rear deck lid, fenders, doors, roof panels on 2005
and newer vehicles, and bumpers. Cowl hoods may
not be taller than half way point of the
windshield. Forward facing scoops are prohibited
on power adder combos unless factory installed or
less than 5 inches from flat area of hood. Inlets
for superchargers must not be exposed to ram air
and pass a "line of sight inspection" from the
front of the vehicle, I.E. they must be blocked
off from a direct source of air this includes
closing off factory holes/grills. Turbochargers
permitted to be forward facing and exposed to ram
air. Factory firewall must be in factory location,
notching and smoothing permitted but must be
identifiable as being in the factory location.
Factory floor must remain under driver and
passenger seat area, fwd of the rear door jamb.
All front ends must be of factory dimensions and
cannot be lengthened and must meet all NHRA/IHRA
height. (See ground clearance note below). Race
car lettering limited to windows, side of cowl
hoods, side of hood scoops, and side of rear
wings, rear quarters, and front chin spoilers, to
maintain street type appearance.
Minimum 3 inches from front of car to 12 inches
behind centerline of front axle, 2 inches for
remainder of car, except oil pan, oil retention
device, and headers.
Aftermarket steering columns are allowed. Factory
type dash accepted. Must have carpet.
Optical devices and magneto ignitions are
prohibited. All entries must have operational head
lights and tail lights.
Aftermarket stock bore space blocks and cylinder
heads are allowed. All entries must utilize a
single carburetor cast intake manifold (see
induction section below). Motor plates and solid
mounts are allowed. Engine must be in stock
location. Mufflers are required on all vehicles
(except turbocharged combos). All SB power adder
engines are limited to 440 cubic inches. SB N/A up
to 480 cubic inch permitted with added 7 lbs. per
cubic inch over 470 and BB N/A limited to 632 and
BOP/BB Mopar power adder limited to 540. 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
Small blocks and power adder Mopar/BOP may use a
"Commercially available/mass produced 4150 or 4500
series cast intake only. The Cast Holley LS EFI
ram intake is permitted on boosted combos. Small
Block N/A may use cast tunnel ram/sheetmetal/dual
carbs w/weight penalty (See*below) Mod motor
permitted aftermarket ram or billet intake. BB N/A
permitted any single entry carb or efi intake.
Nitrous limited to SB and BOP/Mopar BB and BBC/BBF
entries - Progressive nitrous controllers are
allowed. Entries (except 8.2 deck see notes) must
utilize a single stage nitrous plate with one
nitrous, one fuel and one redundant purge
solenoid. Cross bar plate on BB Mopar/BOP
permitted #6 from bottle to solenoid. BBC/BBF
entry permitted single stage, single bar plate
with #6 single line from bottle to solenoid and a
maximum of .110 orifice nos jet. 8.2 deck SBF
combos permitted single stage fogger. Single 10 or
15lb bottle on with a maximum #6 line size from
bottle to solenoid. Foggers must be disconnected
and all solenoids must be capped off. Cold Nitrous
prohibited. Push systems prohibited. Nitrous
plates using fogger nozzles prohibited. Purge line
must clearly exit the hood/cowl or body in a
fashion to not allow purged nitrous to enter the
engine when racing.
Turbocharged (mid frame turbo only see list below)
and supercharged (must be unmodified from
manufacturer) entries are limited to stock valve
angle SB combos only. (SB CHEVY 23 DEGREE
including RR - SB FORD 20 DEGREE 18 DEGREE MOPAR
- FACTORY HEADED SMALL BLOCK FORD MOD MOTOR - LS
CHEVY 15 DEGREE - GEN III Hemi SBM - TFS-R Head
Stock Casting Z06 LS 12 degree Casting for
** NOTE: SB Ford 20 degree SR20 FT1 or T1RI or
equivalent with boosted combo +50 lbs. Aftermarket
LS 12/13 degree with boosted combo +50 lbs.
Pump gas, E85, M1, Q16, and C12/16/23/45 NO2 or
equivalent racing fuel. M5 Prohibited
Any OEM style automatic or OEM manual transmission
is allowed with power adder. Clutch
assisted/clutch-less manual transmission allowed
on N/A. Manual transmissions must utilize SFI
approved bell housing. Aftermarket lock-up
converters and transmission prohibited
Stock type rear suspension or ladder bar only.
Coil over shocks are allowed. Anti-roll allowed.
Aftermarket replacement control arms are allowed.
Stock frame rails must be in factory location,
notching permitted. Corvette permitted any type of
transverse leaf spring rear suspension. Wheelie
bars are prohibited on all cars. Late model GTO
permitted torque arm or ladder bar w/ additional
weight (see below)
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.
POWER ADDER LEGAL TIRES:
MT 3553 255/60-15 ET Street R -50lbs
MT 3453 275/60-15 ET Street S/S -100lbs
MT 3559 275/60-15 ET Street R
MT 3754X 275/60-15 +50 on 8.2 nos entry
N/A LEGAL TIRES:
MT 3559 275/60-15 ET Street R
MT 3754X 275/60-15 ET PRO275 +25 lbs.
MT 3453 275/60-15 ET Street S/S -150lbs
Inline non-stock valve angle head 3050
Mopar BB conventional B1 head/BOP combo 3100
BBC/BBF 588 cu in conventional head combo w/ .110
nos jet 3200 lbs
Any canted valve head 3075
Any non-raised runner 23 degree combo 2950
Any raised runner 23 degree combo - 3000
Blue Thunder Cylinder Heads 4.3 /SC1 3075 and
3.6 - 3050
C3/C302B/C302/Yates style -3000
Any 20 degree ford 3000
Any 20 degree high port SR20 FT1 or T1RI or
equivalent - 3025
TFS-R Ford - 2950
F1A - 91 series - 3050 (-94 series add 200 lbs.)
F1C- 91 series 3100
YSI 3000 (deduct 50 for cast wheel) (+50 for
V30-94 series with ** TBD)
4.0L - NHRA SS COPO - 3200 (must have run NHRA SS
to be legal)
Eaton 2.65L - 3100
N/A WEIGHTS: TBD
N/A Inline head up to 440 2500
N/A Non-Inline head 2600
N/A Buick/Olds/Pontiac/Mopar 2775
N/A (big block with 9.8 standard deck height and
conventional head) 2825 lbs. (add 2.5 lbs. per cu
in over 589) chg.
N/A (big block Ford with standard deck height and
conventional head) 2825 lbs. over 589 add 75 lbs.
N/A (big block with tall deck height and
conventional head) 2875 lbs. over 589 add 75 lbs.
N/A (big block with 9.8 standard height and big
chief head) 2900 lbs. (add 2.5 lbs. per cu in over
N/A (big block with tall deck height and big chief
head) 2925 lbs. over 589 add 100 lbs. chg.
N/A (big block Ford with standard deck height and
non-conventional head) 2925 lbs. over 589 add 75
N/A (big block GM with Symmetrical
port/non-conventional head) 2950 lbs. over 589 add
75 lbs. chg.
N/A (big block Ford with Pro Stock/Symmetrical
type cylinder heads) 3000 lbs. over 589 add 75
- No Billet cylinder heads/blocks
- No Billet wheels on any turbo combo
- No Reducers on turbo or supercharged combo
- Alcohol/E85 legal (meth injection legal on non-intercooled
- All turbochargers (mid frame GT47 or S400
chassis only) must be as manufactured from factory
with cast wheel(GT47-76/S400)
- Cast compressor inducer cannot exceed 76.6mm and
the compressor exducer cannot exceed 116 mm
- 76.5 mm compressor wheels must be "as-cast"
- Turbine wheel must not exceed 96.2 mm x 88.3 mm
- All turbochargers and blowers will have the
compressor cover removed for tech inspection
- Turbos not exposed to ram air may deduct 50 lbs.
(tech directors discretion)
- No muffler required on turbo entry, required on
all other combos
- No bull horns - front exit exhaust permitted but
must not effect timing equipment
- Gear driven supercharger allowed
- Belt driven supercharger deduct 50 lbs.
Serpentine belt driven -100
- Boosted GEN III Hemi SBM add 50 lbs.
- Non Intercooled boosted combos deduct 50 lbs. on
gas (add 50 lbs. boosted combo on M1)
- Late model GTO permitted ladder bar or torque
arm add 50 lbs.
- Cast Tunnel Ram/Sheet-metal/Dual Carbs on SB N/A
add 50 lbs. - Single 4150 carb used with 4150
intake manifold and 4150 plate system deduct 50lbs
deduct 25 lbs. for use with EFI (N/A or NOS only)
- N/A may deduct 150 lbs. P/A deduct 100 lbs. if
using M/T S/S 3453 tire
- N/A BBC and BBF and BOP deduct 25 lbs. for NO
forward facing scoop
- V6 - I4 - I6 entries deduct 200 lbs. deduct 100
lbs. if using NOS with Turbo on I4 and I6
- 8.2 deck nitrous combo deduct 150 lbs. permitted
- Single entry 1 nos/1 fuel or single nos (dry
system) plate deduct 50 lbs.
- 4 NOS Jet dry plates add 50 lbs.
- 2 NOS Jet dry plate not eligible for single
entry plate deduction
- COPO permitted aluminum block
- IRS deduct 50 lbs. leaf spring -25 lbs.
- any SMALL BLOCK COMBO 441 to 465 ci add 2 lbs.
per cubic inch over 440. Blown/BOOSTED combos NOT
permitted over 440 ci
- BB conventional cylinder head list see X275 for
Accepted products deadline for Ultra Street/X275
Motorsports; Requests from manufacturers to have
new products considered for addition to the 2017
season should be submitted before December 23,
2017 for the 2018 season. After this date, Ultra
Street/X275 Motorsports will not consider
manufacturer requests for new products for the
2018 season. Tech director reserves the right to
adjust rules at any time for parity.
ALSO: EVENT / RACE INFORMATION