Last Updated: Nov. 30, 2015

$5,000.00 WINNER
$1,000.00 RUNNER UP
$300.00 SEMIS
$200.00 1/4'S


2016 Leaf Spring Rules

FORMAT: This is a 1/8 mile heads-up class run on a .400 pro tree with a pro ladder. Courtesy staging and auto-start is in effect. THIS IS A SINGLE POWER ADDER CLASS ONLY!

WINDSHIELD/WINDOWS: OEM glass or Lexan windows are permitted.
CHASSIS: Front and rear frame rails required (rear maybe notched for tire clearance). Tube chassis and back-half cars not permitted. Tubing forward of the strut tower or forward of the a-arm mounting point permitted. Front core support may be modified or removed. Aftermarket bolt-on replacement front K-members/sub frames are allowed. Shock tower must be in factory location. Factory wheelbase must be maintained. (+ or – 1 inch) All vehicles must have come from the factory WITH leaf springs.
ENGINE: Billet SB/BB blocks not permitted. All blocks must retain stock bore spacing. 640 cubic inch maximum on Nitrous BB combo and 588 maximum on Boosted BB combo. NA entries over 640 will add weight. See note below.

TURBOCHARGERS: SB Twin turbochargers limited to 80 mm maximum with no reducer(s). Inserts or reducers to achieve inlet dimensions permitted on single turbo applications only. 106 mm max with 98 mm reducer. Any type of air to air or water to air intercooler permitted.

SUPERCHARGERS: Cog or gear driven superchargers are permitted, must meet all factory inlet, outlet, and internal housing dimensions. Any type intercooler is permitted. Roots superchargers permitted. Centrifugal superchargers are permitted. Screw superchargers are not permitted. F3R centrifugal blower will need to be reduced to 110 mm entry – reducer will need to be mounted within one inch of the leading edge of the blower volute.

NITROUS OXIDE: Small block are permitted to run any type of multi-stage nitrous system. Big Block entries are limited to 3 systems.

TRANSMISSION: Any factory style automatic transmission allowed. Electric shifters or air shifters are permitted. Bruno-Lenco not permitted. Add 50 lbs. for Lock-up Transmissions/Converters

INDUCTION: Small Block and Big Block combinations may run any type induction. * see below for additional weight information.

EXHAUST: Mufflers or inserts are required on all cars except for turbo cars.

FUEL: Gasoline or M1 only is permitted. M5 prohibited
Mag + 50#

SUSPENSION: Stock style rear leaf springs permitted. Aftermarket direct replacement components such as: front control arms, front coil over shocks, and rear shocks are permitted. Aftermarket rack and pinion steering allowed. Rear leaf springs and shocks may be moved to accommodate tire clearance, and do not need to be mounted in stock location. Bolt-on or welded sub-frame connectors, rear sway bars, are permitted on all cars. Coil springs are NOT permitted on rear of car. Ladder bar with floaters NOT permitted. Wheelie bars are prohibited on all cars.

TIRES: MT 275 Pro Radial p/n 3754X or MT 275 ET Street SS p/n 3453 permitted


• SB NA – 2500
• SB NOS – 2700

• BB NA – 2800 add 100 for anything over 640
• BB NOS w/24* & greater valve angle - 3150
• BB NOS w/23* & less valve angle - 3200

• SB SINGLE Turbo/Roots Blower (106 reduced to 98 mm /14-71 max)- 3200
• SB SINGLE F3 or v28-123 Centrifugal Blower – 3300 (reducer not required on SB)

• SB TWIN Turbo/Blower - 3350 (80 max no reducer) (+/- 3 mm)

• BB SINGLE Turbo/Blower - 3400 (add 50 lbs. for F3R 130 139/v28/123 with 110 mm reducer)
• Inline 6 / V6 (turbo/nos combos) deduct 500 lbs. from SB Turbo/Blower combo
• Inline 4 / rotary (turbo/nos combos) deduct 800 lbs. from SB Turbo/Blower combo


• 4 and 6 cylinder combos permitted 1 single nitrous nozzle between turbo and intake
• SB NOS add 50 lbs. for multiple systems
• SB NOS add 50 lbs. for canted/splayed/sub 14* cylinder heads
• SB NOS add 25 lbs. for dual carb
• BB NOS add 25 lbs. for extra carb
• NA BB over 640 add 100 lbs.
• Deduct 50 lbs. for MT 275 ET Street SS p/n 3453

If one combination appears to have an advantage rules may be changed at the race director’s discretion at ANYTIME in order to keep a level playing field for all competitors.