17.5 Spec Sprint

Body

Cage – Sprint cars must have a scale appearing contemporary cage made out of rounded stock. The cage must be symmetrical left to right and mounted level to the chassis. Unrealistic shaped cages designed to exploit the rules below are not permitted. Maximum cage width at driver halo, down tubes, and top frame rail: 3.600″. Maximum cage height 5.5″ from top of chassis to top of cage at highest point. All cage and body components such as cage, bumpers, nerf bars, hoods, side panels, tanks, etc. must be mounted on the centerline of the cage. Chassis may not extend outside of the side panels by more than 1/4″ on either side.

Bumpers – A flat, curved or tubular front bumper (or combination of) must be used and may not be designed to direct air or create downforce. Maximum height of front bumper is 1.75” from the bottom of the lowest point of the chassis. Scale appearing side nerf bars must be used on both sides of the car (left side of nitro sprint is optional due to clearance needed for nitro exhaust). A scale appearing rear hoop style bumper must be used. Bumpers and nerf bars must be made of a shock absorbing material.

Tail tank – A traditional scale appearing rounded style three dimensional rear fuel cell must be used.

Headers – Three dimensional scale appearing exhaust headers must appear on both sides of car in “engine area” (left side of nitro sprint is optional due to clearance needed for nitro exhaust).

Side panels – Flat side panels may be made from molded or fabricated polycarbonate. Maximum
height of side panels in front of the driver cockpit is 3.80” from the bottom of the chassis. Must have minimum of 3/4″ high by 2.5″ long openings on both sides of cage in driver compartment. Additional material may be used/added to either side of the side panel openings to replicate a scale appearing driver but may not exceed 1″ x 1″. (Note that the top wing mounts may cover these openings for winged classes.) Side panels may not extend beyond the rear of the cage by more than 0.25”. Side panels may not extend above or in front of the front downtubes. Scale appearing driver arm guards and engine vents may be used but cannot extend more than 3/8″ from the side panels. No other flares or turnouts designed to deflect, trap and/or form a pattern for air to travel in a directed manner are permitted except for those used to cool electronics.

Hood Area– A scale appearing hood must be used and is defined as beginning at the front axle and ending at the front of the driver cockpit. The hood must be symmetrical from left to right. The hood must be tall enough and wide enough to allow room for a scale engine intake and air cleaners (no unrealistically low or flat hoods). Minimum vertical gap from top of hood to bottom of front cage crossbar: .750″. The hood may not drop below the nearest point of the side panels by more than 3/8” and may not have any channels more than 0.25” deep designed to trap or direct air.

Nose Area – A molded or fabricated nose piece may be used and is defined from the front axle forward to the front bumper. Front bumper may not extend more than 3” from front axles. Nose piece (any lexan) must be at least 3/8″ back from the leading edge of the front bumper. Maximum width of nose piece/bumper is 3.75″. Maximum width of any surface designed to add downforce is 3.125”. Nose piece may not extend above the cage downtubes or an imaginary line connecting the downtubes if the cage is a split design.

***Note that the hood and nose piece can be one piece or multiple pieces for the purpose of easy access to electronics and suspension but are defined as above for purposes of aero rules.

Front wing/mounts
 – For front wing dimensions see appropriate wing drawing pdf. The front wing center section may not extend in front of the front bumper. Front wing mounts may be made of lexan but may not exceed 1.75” in length and 1.75” in height and may not extend in front of or behind the center section of the wing.

Top wing/mounts – For top wing dimensions see appropriate wing drawing pdf. Top wing minimum height at leading edge: 5.00″ from bottom of chassis. Top wing maximum height at leading edge: 6.50″ from bottom of chassis. Center section and side panels must be made from at least 3 separate pieces of polycarbonate, carbon or aluminum material. All corners and edges must be rounded and free of sharp edges. Main and Front wings must be mounted so that they are centered on cage, no offset wings. Wing center sections must have all 4 corners set at 90 degree angles, no canted or angled panels. Wings must also be mounted level from side to side. Center section of wing may not extend beyond leading or trailing edge of side panels. Side panels must have braces that hold side panel rigid at 90deg. to center section during race conditions. Two braces are required from top of the center foil to the left sideboard and one brace is permitted below the center foil to the right side board. Braces can be a maximum of .750″ wide and front edge of front brace must be no more than 1.5” back from side panel leading edge. Side Panels may have front, back, top and bottom turnouts of no more than .375″ and are included in max dimension. Flat foil center sections will be allowed a .250” turndown at the leading edge.

No additional lexan or any other material may be mounted to nerf bars, bumpers, cage, wing or any other part of the car that will trap, alter, or direct air flow for the purpose of gaining an aerodynamic advantage.

The 6×6″ wing will be the standard Sprint Car wing size.

Top wings are mandatory and front wings are optional for all sprint classes.

6×6″ Foam Tire Wing

Motor

DODC SPEC 17.5 MOTORS (Schuur Speed 17.5 Extreme Stock SS, Novak Ballistic, Novak Premium Ballistic and Novak High RPM Ballistic 17.5 motors only.) Any parts standard to any of the listed motors can be used including, ceramic bearings and vented endbells.) Motors shall be no less than 10° F below the temp of a control motor.

Intermixing of manufacturer parts will not be allowed. No parts of motors may be modified, altered or removed in any way. All stock hardware must be used, I.E. no aluminum or titanium screws/bolts. The minimum resistance allowed is 21.1 milli-Ohm’s at 75* F. It is not legal to unwind, rewind, unsolder, resolder, re-epoxy, add epoxy or any other coating or material to any part of the stator. If the solder tabs are found to be tampered with you will be immediately disqualified. All motors are subject to disassembly at any given time during an event at the race directors discretion.

Spec Class Motors:
1) Schuur Speed 17.5 Extreme Stock (#SUU540174) Black can & End bell Only. Signature Select Series will NOT be legal. Ceramic bearings may be used but must be the same dimensions. The Schuur Speed motor must use the 12.5mm x 24.2mm rotor that comes standard in the Schuur Speed Motor (#SUU501126) Removal of Stator from can will result in immediate disqualification.

2) Novak Ballistic, Premium Ballistic, High RPM Ballistic and Vulcan Spec 17.5 motors only. Any parts standard to each design/make must be used respectively. Ceramic bearings may be used but must be the same dimensions as the original bearing. All Novak motors must use the 12.5mm (MPV5955) pre 12.3mm (NOV5941) rotor.

Approved Batteries:
Fantom Racing 5200 mAH 50C battery (FAN26168D)
RC King 5200 30C (#5230-2S1PD)
LiPo Onyx 2S 7.4V 4000mAh 25C Hard Case Deans
LiPo Onyx 2S 7.4V 5000mAh 25C Hard Case Deans
Dynamite DYN9005EC Reaction 5000mah 2S 30C
Dynamite 5302d Speedpack Gold 4200mAh 30C
DODC SPEC Li-Po 3200mah

Batteries must use stock Deans style plug for connection to ESC. Checked batteries shall be no more than 10° F above the temp of the control pack.

No additional batteries are allowed including those used to power receivers or cooling fans.

DODC Spec motors must be out of the box stock, with no modifications allowed. No parts of motors may be modified, altered or removed in any way. You can replace any parts of the motors with stock OEM replacement parts only. ie: rotors, stators, etc.

Spec Speed Control
Novak Edge or Novak Havoc
SPEED PASSION Reventon Stock Club Race part number:SP000048
Hobbywing Justock Black Edition 81020001 & Blue Edition (81020000)
Hobbywing XeRun XR10 Justock (30112000)
Tekin RS Gen2 Spec ESC (TEKTT1155)

IF YOUR MOTOR, BATTERY, OR SPEED CONTROL IS FOUND TO BE ILLEGAL BY THE RACE DIRECTOR, YOU WILL BE BANNED FROM ALL SPORTSMAN AND SPEC RACING FOR ONE YEAR AND AREA TRACKS AND RACE SERIES WILL BE NOTIFIED.

Chasis

General – Maximum Overall Length: 18.000″. Maximum Chassis width: 4.025″

Minimum Weight: 55 oz

Foam tires or 2.0 or 2.2 rubber street treaded.

All foam tires must be wiped clean of any traction compound before setting the vehicle down on the track. Tires will not be allowed to leave tracks on the racing surface or pit lane. One warning will be issued before disqualification for the day.

No mini pins, ribbed or sticks.