D3 2011   Retro Pro   Regulations

The D3 Board of Directors invites all other affiliates to submit their own racing calendar for publication herein. Publication of the rules shown below in other Forums is permitted by Slotblog! if unaltered, unless with approval of the relevant D3 Committee members.

D3 2011 1/24 Retro Pro racing class rules (version V6, 12/21/09)

1. Intent: The intention of this class is to provide a class of scratch-built slot cars reflecting the spirit of the early 1970's racing era at low cost, to attract more experienced racers and builders.

2. Dimensional Specifications

2a. Maximum Overall Chassis Width: 3.125" (measured across any part of the chassis)
2b. Maximum Rear Tire width: 0.810"
2c. Minimum Rear Tire diameter: 0.790"
2d. Minimum Front Tire width: 0.063". O-ring tires allowed.
2e. Minimum Front Tire diameter: 5/8"
2f. Minimum Clearance: 0.040" (measured under rear axle excluding gear) and 0.015" ( measured at the lowest, most forward part of the chassis ). Both clearances measured with car standing on a flat tech board on its wheels, without guide.

3. Chassis construction

3a. Chassis type: Any personally-built or commercially-available scratch-built chassis conforming to these specifications and to the spirit of the intent statement is allowed.
3b. Chassis Materials: Brass sheet, rod, and tube; steel wire, pin tubing, and guide tongues are allowed. Other than guide tongues, stamped steel parts and EDM or laser-cut parts of any material are not allowed unless submitted for approval. Absolutely no form of pillow block construction (as in individual sheet-metal axle holders soldered into slots cut in any form of sheet-metal support) is allowed.
3c. Drive type: open to the imagination.
3d. Hinged movements in any direction are allowed. Centerline hinges (Flexi hinges) are not allowed. No chassis movement, dynamic or induced, may extend the overall chassis width to more than 3.125". Hinged or fixed side structures cannot "hang" below the line formed by the main rails.
3e. Front axle: A single straight, one-piece front axle is required, carrying both front wheels. The axle may be fixed or rotating inside a tube. No visual obstruction of any kind across either front or rear wheels must be seen when viewing the car from its sides. NO hinged front wheel movements are allowed (i.e. no "L" arms). Front wheels may rotate independently.
3f. Rear axle:  two methods are allowed:
1/ An axle tube of constant diameter capturing the axle bearings. The axle tube may be notched for motor clearance. This axle tube must be held by the steel, bronze or brass-wire main rails.
2/ The bearings are set in a one-piece  formed sheet brass bracket that may also hold a bolt-on motor bracket soldered to the base of the main rails.

3g. Guide: One guide flag centered on the longitudinal axis of the chassis (i.e. no sideways "free float" or offset) is allowed.

4. Motor rule

4a. Motor type: Pro Slot PS4002, unmodified Falcon 1 to 7 or TSR D3.
Modifications allowed only to the PS4002 and limited to:
-Fitting of screws to hold end bell to can, installation of ball bearings and shunt wires. Magnets MUST remain stock items. Magnets may be glued to can with epoxy.
-Allowed armatures: Pro-Slot X12 or lesser armatures (I.E. "Puppy Dog", "Big Dog"...). Minimum armature diameter: 0.512".  Minimum stack length: 0.350"


5. Body rules

5a. Body style: Bodies must be originals or exact reproductions of 1966 to 1973 Pro-Racing bodies by Russkit, MAC, Lancer, Associated, Dynamic etc. No "flattened" or "aerodynamically improved" bodies allowed (i.e. no molded-in spoilers, wings etc that were not on the original full-size car or original mold). Front wheel arches must be cut out. Rear wheel arches may be left closed if the original full-size car ran with closed wheel arches. Bodies must be presentably painted and carry at least three racing numbers, one on each side, and one on the front. Bodies with molded-in cockpits are not allowed. No part of the chassis or tires may be seen when looking on the car from its top.

5b. No air-control devices may be added to the one-piece bodies.

Example of car for this class:





Approved bodies listing:

MAC-V10 Porsche 917PA
MAC-V02 Ti22
MAC-V04 Lola T290
MAC-V05 Ferrari 612
MAC-V06 Ferrari 512M
MAC-V07 Gulf-Mirage
MAC-V08 Porsche 917-30
MAC-V09 McLaren M20
TrueScale Porsche 917
ToyTech March 707
OS-400 BRM (formerly Dynamic Can-Am Porsche)
OS-401 Shadow (formerly Dynamic Lola T260)
OS-404 Honda XR (formerly Lancer Porsche 908)
OS-04 Ti22

Other bodies must be submitted to The Division III Committee members for approval.
Bodies must be molded from material with a minimum thickness of 10 thousands of an inch.

5c. Cockpit: Cockpits must be fully opened following the natural line of the windscreen and body. A separate 3-D driver figure painted in at least 2 colors must be fitted.

NOTE: The use of "speed rubber" tires (regardless of their brand or name) that have a partial silicone content that effectively leave a deposit on the track is forbidden.
The use of such tires during qualifying or racing will cause immediate disqualification of the entrant/racer and a single warning. A second offence will cause permanent banning from D3 racing.

Any matter regarding this class must be submitted in writing to a member of the D3 Board of Directors

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