LAS VEGAS // Nov 18-21, 2021
Precision Turbo Pro Modified presented by Energy Manufacturing & Payless Water Heaters will run 1/4-mile and qualify for a 32-car field (with Alternates) and be put on a 32-car Pro Ladder…..Unless fewer than 32 cars qualify, then we will follow the NHRA "Official Ladder" for that field size....
The SCSN follows NHRA Advanced ET Safety Rules - Refer to the NHRA rulebook.
REQUIREMENTS AND SPECIFICATIONS...
Funny car or one-piece bodies not allowed even if equipped with doors. Maximum front end overhang of 45” as measured from centerline of front spindles. An SCSN accepted extension may be used to create 45” overhang if the front-end overhang of the original body is less than 45”. All bodies must originate from a documented production vehicle. All new cars must be accepted by the SCSN Technical Services Department prior to construction. DOORS: Required. Doors must be functional and able to be opened from both the inside and outside
of the vehicle. Doors may be fabricated from carbon fiber, fiberglass or metal.
Must be in conventional left-hand drive location.
Minimum of 3” required from front of car to 12” behind front axle centerline, 2” minimum for remainder of car.
SUSPENSION: Race car type suspension required. Solid suspension prohibited. Shock absorbers
required for all four wheels. Lockup shocks prohibited. Active suspension of any kind prohibited. Any
ability to make on-track setting/rate changes based on “real time” data or input from any source is
prohibited. Electrically or pneumatically controlled, hydraulic shocks and/or struts are permitted,
provided all adjustment settings/changes are preset before the run. Only 1 three-wire shielded cable
connection is permitted from the top of the shock/strut to the shock/strut controller. Electrical
connections of any other kind to or from the shock/strut prohibited. Shock/strut travel sensors
permitted but may ONLY be connected to the vehicle data recorder. Shock/strut control boxes that
have connections for travel sensors must have the pin removed from the connector. Connection to
serial port on control box prohibited once car reaches the ready line. All wiring must be visible and
DRIVELINE AND ENGINE
Flywheel and clutch meeting SFI Spec. 1.3, 1.4, or 1.5 certification required. Three
discs maximum with a maximum disc diameter of 11 “ or four discs maximum with a maximum disc
diameter of 8 “. Flywheel shield meeting SFI Spec 6.2 or 6.3 required. Maximum depth of flywheel
shield: 9.400 “. Clutch must be manually operated by driver’s foot: electronics, pneumatics,
hydraulics, or any other device may in no way affect the clutch system. Throwout bearing must
release all fingers, levers, stages, etc. simultaneously. Staged or variable release clutches of any
CYLINDER HEADS: Hemi, canted-valve, or wedge heads permitted. Billet heads permitted. Maximum one spark plug per cylinder.
ENGINE CONTAINMENT SYSTEM: SFI Spec. 7.1 lower engine containment system required. If a flexible 7.1 system is utilized, it must be supported by a belly pan made from carbon fiber or .032” aluminum with a minimum 2” vertical lip.
MAXIMUM CUBIC INCH ENGINE DISPLACEMENT: 526 cubic inch maximum for
Turbocharged entries 960 cubic inches (At different min weights) for Nitrous powered entries, unlimited CI for NA entries, Supercharged
entries refer to weight section below. All rules subject to change at the sole discretion of the SCSN Technical Services Department.
ENGINE SETBACK: Maximum of 10% of total vehicle wheel base as measured from the centerline of the forward front spindle to center of front spark plug hole.
FUEL: Alcohol, gasoline and methanol allowed. The use of nitro-methane and/or propylene oxide is strictly prohibited.
NITROUS OXIDE: Prohibited on Turbo and Supercharged entries. Water injection permitted on Nitrous entries only, only water permitted in water injection system.
SUPERCHARGER: Hi-helix or standard helix Roots type supercharger only. Manifold burst panel
meeting SFI Spec 23.1 plus restraint system meeting SFI Spec 14.2, including injector restraint straps
mandatory. Intercoolers, variable multi-speed supercharger devices prohibited. The top opening may
not exceed 12 “ in length or 5 “ in width. The entire inlet opening must be on/in the upper surface
only. The maximum length from the front of the supercharger drive pulley to the leading edge of the
rotor is 15 “. Offset drive pulleys, spacers, modified cases, or attaching methods may not be used to
add to the 15” maximum. The rotors must be driven from the front (both the external drive and the
internal gearing. Any inlet/outlet cavity in front of the rotors is restricted to a maximum of 3.000“
measuring from the face of the bearing plate to the front of the cavity. Roots Type: Maximum size: 14-
71, 22 1/4-inch case length, 11- ¼” case width, 19” rotor length; maximum rotor diameter:5.840
including fixed stripping. The case must be one piece with removable front and rear bearing end
plates; rotor must be contained within one-piece case. Roots-type high helix: Must adhere to same
maximum case dimensions and maximum rotor cavity diameter as standard Roots. Rotor helix angle
may not exceed 6.5 degrees per inch (123.5 degrees total over 19” maximum rotor length). Screwtype supercharger legal but has limitations (See weight section below).
TURBOCHARGER: Twin Turbochargers permitted to race at 2650 base weight are limited to 88mm NHRA Legal Pro Mod "As Produced" Turbos. Turbocharger size will be verified by measuring the housing bore at the leading edge of the impeller wheel. 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. (Larger Turbo sizes are permitted at higher weights see Weight Section Below)
2300 pounds for Nitrous entries (911-960ci Max)
2200 pounds for Nitrous entries (866-910ci)
2100 pounds for Nitrous entries (up to 865ci)
2350 pounds for Supercharged entries (up to 526ci Max)
C ROTOR - 2425 lbs Up to 92% Overdrive
C ROTOR - 2475 lbs Up to 98% Overdrive
C ROTOR - 2575 lbs Up to 108% Overdrive
C ROTOR - 2625 lbs Unlimited Overdrive
D ROTOR - 2450 lbs 108% Max Overdrive
2300 pounds for Centrifugal Supercharged entries (Small Blocks)
2500 pounds for Centrifugal Supercharged entries (Big Blocks up to 526ci)
2600 pounds for Centrifugal Supercharged entries (Big Blocks 527ci up to 565ci)
TURBOCHARGED BIG BLOCK:
2350 pounds for Single Turbocharged entries
2575 pounds for Twin Turbocharged entries (Up to 88mm Max)
2700 pounds for Twin Turbocharged entries (up to 94mm Max)
2850 pounds for Twin Turbocharged entries (up to 98mm Max)
2900 pounds for Twin Turbocharged entries (up to 104mm Max)
TURBOCHARGED SMALL BLOCK:
2200 pounds for Single Turbocharged entries
2350 pounds for Twin Turbocharged entries (88mm Max)
2200 pounds for Twin Turbocharged Modular entries (88mm Max)
Add: 50lbs for the use of a “Lock-Up” Torque Converter in any Boosted Big Block Combo
Deduct: 75lbs for use of a Torque Converter in Small Block Applications Only
Deduct: 75lbs for Non-Hemi Big Block Boosted Combo
Deduct: 100lbs for Pontiac Based Engines
PRO MOD REQUIRED DECALS:
CLASS SPONSOR DECAL:
"Precision Turbo" decals on both lower front fenders forward of the wheel opening
SCSN TITLE SPONSOR DECAL:
"Comp Cams" Decal must be placed on the upper windshield in the center. All Decals will be available during registration at the SCSN Event Trailer
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
CLASS PRESENTED BY SPONSOR DECAL:
"Energy" decal must be installed on base of windshield on the passenger side or on both
lower front fenders forward of the wheel opening
SCSN SERIES DECAL:
SCSN Decals must be placed on both left & right sides of race car on the 1/4
Window, 1/4 Panel or Rear Wing in a highly visible location
CONTINGENCY PROGRAM & CONTINGENCY DECALS:
All contingency decals may appear anywhere on the vehicle in a clear and organized fashion. Contingency decals may not be overlapped or modified. Most decals are available at the SCSN Event Trailer, but in the event the SCSN does not have the decals in stock, it is the racer's responsibility to obtain the proper decals to be eligible for the Contingency payout.
RACE DAY POLICY'S
FIELD SIZE AND LADDER:
Pro Modified will qualify for a 32-car field (with Alternates) and will be put on a 32-car Pro Ladder. If
less than 32 cars enter, we will follow the NHRA "Official Ladder" for the qualified field size....
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.
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 before the drivers meeting on Sunday morning. This
will give the qualified cars overnight to get the cars repaired.
TOW BACK & TOW VEHICLES:
All Pro Modified 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 Pro Modified 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.
The Auto-Start System will be turned on with a 7-sec timeout
All vehicles must take the tree, and run down the 1/4 mile & Scale
$15,000 / To Win
$1,500 / Runner-up
$500 / Semi's
$250 / Quarters
Class Entry Fee: $350 (Plus $80 Track Tech Card)