LIMITED DRAG RADIAL

DESIGNATION:
The class designation is LDR. All entrants must display this designation on both sides of their car with car number.

FORMAT:
This is a 1/8th mile, heads up category running on a .400 Pro tree with a maximum of a 32-car field, professional
pairing ladder. This is a single power adder class only!

SAFETY:
All NHRA and Local Track Safety rules apply for car and driver, including the use of an oil retention device
and/or engine diaper is MANDATORY. 

BODY:
The car must retain its original appearance, profiles, and dimensions. No aftermarket one-piece bodies. OEM door
jamb and quarter panels must be used. No modified front ends to achieve maximum NHRA/IHRA overhang, must
stay within original body dimensions. Must retain factory body lines with removable composite components as in
hood, front bumper, front fenders, doors, and deck lid. Any beam tripping devices forward of the bumper are
prohibited. Aftermarket front bumpers (“Ex. Snowplows or Valances”) cannot have more than 2 inches of overhang
over the stock bumper dimensions, failure to abide by this rule will result in disqualification. Aftermarket wings and
spoilers are permitted. A hood must be used; scoop or hood must cover entire induction system. Exceptions are
throttle bodies or carburetors on naturally aspirated and nitrous oxide assisted engines along with intake
manifolds/throttle bodies on boosted engines. Those may protrude through the hood for clearance, if needed.
Forward facing hood scoops/turbocharger/supercharger inlets are permitted. OEM/Lexan windows are permitted.
Front ends must be within the spirit of the rules and legality is at the discretion of the race director. Firewall must
originate in the stock location; factory firewall can be modified, and aftermarket firewall is permitted. See maximum
overhang weight table, below in the weight additions/reductions section.

CHASSIS:
Door cars only, no pro mod or full tube chassis. Double frame rail permitted, if located inside of stock frame rail.
Backhalf style cars are permitted. No Wheelie Bars. Any rear suspension is permitted. Factory front frame rails are
mandatory, they can be modified. Frame rails must start at stock firewall location and must extend to the center of
the front spindle. Factory equipped ‘bolt-in’ subframe cars are permitted an aftermarket bolt-on front end (Ex., Smith
Racecraft) for ’62-’74 Nova and ’67-’81 Camaro/Firebird, must bolt in. Factory wheelbase for year/make/model must
be maintained, (+/- 1 inch). A minimum height of 3 inches from the front of the vehicle to 12 inches behind front
spindle center line is mandatory. A minimum height of 2 inches for the rest of the vehicle is mandatory (except for oil
pan and headers).

BALLAST:
Any material used for the purpose of adding to a car’s total weight must be permanently attached to the car’s
structure and must not extend in front of or behind the rear of the car’s body. No liquid or loose ballast permitted
(water, sandbags, rock, shot bags, metal weights, etc.). Removable weight must be securely mounted to the frame or
frame structure by a minimum of two 1/2-inch diameter steel bolts per 100 pounds, or one 3/8-inch steel bolt per 5
pounds. All other weight bars, pucks, etc., must use a minimum two 1/2-inch diameter SAE Grade 8 bolts for
attachment per 100 pounds.

ENGINE/POWER ADDERS:
All engines must have a diaper, belly pan or oil retention device. The cubic inch limit for any Big Block combination is
910 cubic inches. All SMALL BLOCK engines are limited to 4.600 bore spacing and 570 cubic inches on naturally
aspirated or nitrous assisted combinations. All boosted small block entries are limited to 4.600 bore spacing,
10.200-inch deck height and 505 cubic inches. Nitrous oxide is permitted to run any type of multi-stage nitrous
system with no restrictions. Nitrous entries must have bottle securely contained in a bottle bracket. Maximum bore
spacing for all boosted combinations is 5.000 or less. Turbocharger combinations are limited to a maximum 122mm
single turbo or a set of 88mm twin turbochargers. Hemispherical headed big blocks are prohibited to use twin
turbochargers as their selected power adder. Refer to weight addition/reduction section below for twin turbocharger
clarification. The maximum specifications for a single turbocharged combination are COMPRESSOR WHEEL
(inducer-122mm tip to tip, exducer-159mm maximum) and TURBINE/EXHAUST WHEEL (inducer-130mm maximum,
exducer-114mm maximum). The maximum specifications for a twin turbocharged combination are COMPRESSOR
WHEEL (inducer-88.9mm maximum, exducer dimensions-134mm maximum, measured at the backing plate),
(non-extended exducer tip-to-tip measurements may not exceed 135mm), (extended exducer tip-to-tip
measurements may not exceed 142.5mm) and TURBINE/EXHAUST WHEEL (inducer-113mm maximum,
exducer-103.5mm maximum). The maximum diameter of the housing bore at the leading edge of the wheel may not
exceed 2mm more than the maximum allowable turbocharger size permitted. Compressor map groove will not
exceed .250 of an inch. Turbochargers will be verified by measuring the housing bore at the leading edge of the
impeller wheel and must retain the contour of the compressor housing, stepped or clipped compressor wheels are
prohibited. Inserts or reducers to achieve inlet or outlet dimensions are prohibited. Any inconsistent modifications to
compressor or turbine wheel, blades, hubs, cover, or housing is PROHIBITED. Boreless shaft turbochargers are
prohibited. Boreless compressor wheels are prohibited. Machined turbine hubs are prohibited. Compressor wheel
tip-to-tip must be able to be captured by the checking tool, a minimum of 0.200-inches. Supercharger combinations
are limited to a single centrifugal supercharger at a F4-140 maximum, with inducer measuring 5.47-inches or
138.9mm and exducer measuring 7.22-inches or 183.39mm, small block and big block. The only F4 transmission
blowers allowed are the F4X-140 and the F4R-136. Maximum size on all twin centrifugal supercharged combinations
is base F1X, (F1X-12 is prohibited). Any modification to factory impeller, housing or housing size is strictly prohibited.
Roots superchargers are restricted to a 14-71 maximum. Screw superchargers are permitted as a C-Rotor design with
92% overdrive as the maximum. Dual power adders are strictly prohibited across all combinations. All forms of power
adders (nitrous, turbochargers and superchargers) must be commercially available to the general public for purchase
and use.

INLINE 6-CYLINDER/INLINE 4-CYLINDER COMBINATIONS:
Inline 6-Cylinder/Inline 4-Cylinder combinations are permitted under the following guidelines: a maximum of a
106mm single turbocharger with gasoline or methanol only as fuel of choice. Nitrous oxide is permitted as dual
power adder for this combination only with a .067 nitrous jet limit. Intercoolers are also permitted with gasoline or
methanol combination. Any transmission is permitted. Weights can be found in the weight table.
MODULAR V8 TURBO COMBINATIONS:
Modular V8 turbo combinations are permitted under the following guidelines: a maximum of a 122mm single
turbocharger with gasoline or methanol only as fuel of choice. Intercoolers are also permitted with gasoline or
methanol combinations. Any transmission and lockup is permitted. Weights can be found in the weight table.

ELECTRICAL:
All entries must be self-starting from inside the vehicle. A master cut-off switch is mandatory on the rear of the car
with an on/off sticker. Any electronic ignition system is allowed, see below for weight additions/reductions.
Computer/Data Recorders are permitted.

EXHAUST:
Exhaust may exit underneath car or out the front fenders/valance but must not affect timing or staging beams.
CO2 SYSTEM AND LINE:
The first TWO feet (minimum) of the line coming from the CO2 bottle must be 1/4″ plastic line with push-locks. No
braided steel lines direct from the CO2 bottle to ensure no nitrous oxide is being used. Braided steel line may be used
after the first two feet of plastic/push-lock line to protect the line running through the firewall and/or around
exhaust system.

INTERCOOLER/WATER INJECTION:
Any intercooler is permitted on gasoline combinations only. Must be securely mounted to chassis or mounts with
preferred hardware. Water box must be contained in a safe environment with a top to enclose water/ice during the
run. Intercooler combined with a methanol fueled combination is prohibited. Water injection is permitted on
gasoline combinations, cannot contain any amount of methanol, ethanol, or any other additive, must be pure water
in the injection system.

TRANSMISSION/DRIVELINE:
Any transmission permitted. Any converter permitted. Lock-Up Transmission/Converter is permitted on naturally
aspirated, nitrous oxide and diesel combinations only, prohibited on turbocharger or supercharger combinations.
Boosted combinations may not have a lock-up transmission or torque converter in the car, even if not in use. Removal
of lock-up mechanism and clutch hub does not define a converter as a non-lock-up unit. Must use non-lock-up length
bellhousing of 6.5 inches on 400, Ty-Drive, Lenco Drive, and 7.5” on QuickDrive, measured from mid-plate to mounting face of transmission. Naturally aspirated, nitrous oxide and diesel combinations with a lockup must use
lock-up length bellhousing of 7.5 inches on 400, Ty-Drive, Lenco Drive, and 8.5” on QuickDrive, measured from
mid-plate to mounting face of transmission.

FUEL:
Any gasoline, E85 or M1 permitted. M5 is prohibited. No nitromethane or additives.

WHEELS/TIRES:
Any brand 275/60-15 Drag Radial. Mickey Thompson 295/65-15 Drag Radial (PN: 3558) and Hoosier 295/65-15
DR2 (PN: 17316DR2) will also be legal tire options. Must stay on the same tire throughout the entire event.

WEIGHTS:
All weights are minimum with driver in car.

NATURALLY ASPIRATED:
• Small Block – No Minimum
• Big Block – No Minimum

NITROUS OXIDE:
• Small Block – 2,200 lbs.
• Big Block (4.840 Bore, Non-lockup or lockup Transmission) – 2,435 lbs.
• Big Block (5.000 Bore, Non-lockup or lockup Transmission) – 2,460 lbs.
• Big Block (5.200 Bore, No Lockup Transmission) – 2,660 lbs.
• Big Block (5.200 Bore, With Lockup Transmission) – 2,735 lbs.
• Big Block (5.300 Bore, Up to 910 CI Maximum, No Lockup Transmission) – 2,725 lbs.
• Big Block (5.300 Bore, Up to 910 CI Maximum with Lockup Transmission) – 2,800 lbs.

TURBOCHARGER:
• Inline 4 Cylinder – 2,600 lbs.
• Inline 6 Cylinder – 2,650 lbs.
• Small Block, Single Turbo – 2,650 lbs.
• Small Block, Twin Turbo – 3,050 lbs.
• Big Block, Single Turbo – 2,750 lbs.
• HEMI/HEMI Headed Big Block, Single Turbo – 3,000 lbs
• Big Block, Twin Turbo – 3,250 lbs
• Diesel, 6-Cylinder (Cummins) (106mm Maximum Single Turbo or 76mm Maximum Twin Turbo, .099 Nitrous Jet
Limit, Lock-Up Permitted) – 3,300 lbs

SUPERCHARGER:
• Small Block, Roots – 2,650 lbs.
• Big Block, Roots – 2,875 lbs.
• HEMI, Roots – 2,975 lbs. (+50)
• Small Block, Screw – 2,850 lbs.
• Big Block, Screw – 3,050 lbs.
• HEMI, Screw – 3,275 lbs.
• Small Block, Single Centrifugal (ProCharger F1, F3D or Equivalent) – 2,650 lbs.
• Small Block, Single Centrifugal (ProCharger F2 or Equivalent) – 2,700 lbs.
• Small Block, Single Centrifugal (ProCharger F3R or Equivalent) – 2,750 lbs.
• Big Block, Single Centrifugal (ProCharger F1, F3D or Equivalent) – 2,800 lbs.
• Big Block, Single Centrifugal (ProCharger F2 or Equivalent) – 2,850 lbs.
• Big Block, Single Centrifugal (ProCharger F3R or Equivalent) – 2,900 lbs.
• HEMI/HEMI Headed Big Block, Single Centrifugal (ProCharger F1, F3D or Equivalent) – 3,010 lbs.
• HEMI/HEMI Headed Big Block, Single Centrifugal (ProCharger F2 or Equivalent) – 3,060 lbs.
• HEMI/HEMI Headed Big Block, Single Centrifugal (ProCharger F3R or Equivalent) – 3,110 lbs.

WEIGHT ADDITIONS/REDUCTIONS:
• 25 lb. Weight Addition for any Small Block, boosted combination, with bore spacing over 4.510 and capped at
4.600.
• 100 lb. Weight Addition for Factory Bolt Pattern AMC Small Block Heads
• 50 lb. Weight Addition for Alcohol Big Block, Twin Turbocharged All-Billet Combination (Block and Cylinder Heads).
• 50 lb. Weight Addition for any Transmission with four (4) or more forward gears in use (must be approved by tech
official).
• 240 lb. Weight Addition for the ProCharger F3R-140 and F4X-140 Centrifugal Supercharged Hemi Combinations.
• 100 lb. Weight Addition for the ProCharger F3R-140 and F4X-140 Centrifugal Supercharged Wedge Combinations.
• 210 lb. Weight Addition for HEMI Headed Small Block Combination.
• 50 lb. Weight Reduction for Conventional Headed BBC Combinations on Methanol/E85.
• 75 lb. Weight Reduction for Conventional Headed BBC Combinations on Gasoline.
• 50 lb. Weight Reduction for Boosted Combination with Cast Cylinder Heads.
• 50 lb. Weight Reduction for Boosted Combination with Cast Block.
• 300 lb. Weight Reduction for Modular Ford Combinations. (+50)
• 75 lb. Weight Reduction for Factory Bolt Pattern Big Block Buick/Olds/Pontiac Heads
• 50 lb. Weight Reduction for Non-Extended Tip Compressor Wheel turbochargers on Twin Turbocharged
Combination Only. (Competitors may be asked to remove compressor cover for verification at any time by technical
inspection team)
• 75 lb. Weight Reduction for BB-Nitrous, 5.3 Bore Space with 11.8 and shorter deck height.
• 200 lb. Weight Reduction for Twin Turbocharger, V8 combination with 80.9mm and smaller inducer compressor
wheel. (All other specs are outlined above in ENGINE/POWER ADDERS section) (Modular Ford Combination
excluded)
• 150 lb. Weight Reduction for Single Turbocharger, V8 combination with 98mm and smaller inducer compressor
wheel.
• 65 lb. Weight Reduction for Single Centrifugal Supercharged, small block combinations with inducer sizing of
123mm and smaller.
• 50 lb. Weight Reduction for Centrifugal Supercharger Combination on Gasoline.
• 50 lb. Weight Reduction for Leaf Spring Rear Suspension.
• 25 lb. Weight Reduction for Triangulated Stock-Style Suspension with upper bar 35% shorter and not parallel to the
lower bar, upper bar must travel at a minimum of 45 degrees from housing to chassis mount (must be approved by
tech official).
• 25 lb. Weight Reduction for vehicles originally equipped with torque arm suspension (must be original
configuration and location).
MAXIMUM OVERHANG WEIGHT BREAK TABLE:
• 41-45” Overhang – No Weight Break
• 36-40” Overhang – 10 lb. Weight Reduction
• 31-35” Overhang – 20 lb. Weight Reduction
• 26-30” Overhang – 30 lb. Weight Reduction
• 21-25” Overhang – 40 lb. Weight Reduction – This would be based on the centerline of the most forward front wheel to the tip of the factory front bumper, this does not include the front valance.
* Rules are subject to review at any time. 

LDR REQUIRED CLASS DECALS: Decals will be available at Sign-Up at the SCSN Trailer

CLASS SPONSOR DECAL:

“TBD” decal must be installed on base of windshield on the passenger side.

(Bottom left-hand side when looking at front of vehicle windshield)

SERIES PRESENTED BY SPONSOR DECAL:

“FuelTech” decal must be installed on base of windshield on the driver’s side. (Bottom right-hand side when looking at

front of vehicle windshield) Decals will be available during registration at the SCSN Event Trailer

SCSN TITLE SPONSOR DECAL:

“” Decal must be placed on the upper windshield in the center

SCSN SERIES DECALS:

SCSN Decals must be placed on both left & right sides of race car on the 1/4 Window, 1/4 Panel or Side of Rear Wing in a

highly visible location

RACE DAY POLICY’S

Field Size and Ladder:

LDR will qualify on a 32-car field (with Alternates) both will be put on a 32-car Pro Ladder. If less than 32 cars enter, we

will follow the NHRA “Official Ladder” for the field size.

SCALES:

After each qualifying and elimination pass, all cars must stop and weigh at the track scales. If you lose in eliminations,

and your opponent fails to make weight you will be reinstated into the eliminations only if you made minimum weight

requirements. If both cars failed to make minimum weight, both cars will be disqualified. It is the driver’s responsibility

to verify with each track scale, the weight of his/her car prior to each race day. There will 5lb error factor allowed.

ALTERNATES:

If there are more than 32 cars qualifying for the 32-car field, we will start inserting alternates (To replace broken

qualified cars) starting at spot 33 and so on… If you are an alternate, and a spot opens, you will be inserted in the 1st

available position 

TOW BACK & TOW VEHICLES:

All LDR entries can tow to staging lanes and to the track scales with a golf cart or other similar small tow vehicle. All

carts will be subject to search by a SCSN Official at any time.

ALTERNATING LANES DURING QUALIFYING:

Each LDR driver must alternate lanes during qualifying. If you choose to ignore this rule, your second consecutive pass in

the same lane on the same day will be disqualified.

AUTO-START:

The Auto-Start System will be turned on with a 7-sec timeout

BYE-RUNS:

All vehicles must take the Tree (Scale for opportunity at Lane-Choice for next round)

Once Your Vehicle Passes Tech Inspection, There Are No Refunds

PAYOUTS:

$3,500 / To Win

$1,000 / Runner-up

$250.00 / Semi’s

CLASS ENTRY FEE: $200 (Plus $80 Weekend Track Tech Card Purchased at Racer Gate)