Here are the rules pertaining to TL-01 spec classes (I cut out almost everything that would be specific to the on-road cars....)
1. Tamiya parts only. No parts from other manufactures unless specified here.
2. Any manufacturer’s electronic speed control, radio equipment, servo saver, antenna, antenna mount, pinion and spur gears, spur gear adapter, ball bearing, tire inserts are allowed in all classes.
3. A 27 MHz or 75 MHz radio system must be used. A minimum of 2 frequencies is required for use at the events. Spektrum systems are also allowed.
4. The batteries that are allowed for the 2006 season are: Sanyo NI-CD 2400, Sanyo NI-MH HV 3000, 3300 & 3600, Panasonic 3000 Ultra Metal Hydride, Panasonic 3000 Stock Metal Hydride, GP (Gold Peak) 3300 & 3700, Intellect Batteries 3600, 3800 and LRP 3700, EPIC 3800. LIPO batteries are not legal at this time. Sport packs that are readily available at hobby stores are legal as long as they are assembled from the general hobby industry i.e. Orion, Peak, Reedy, Duratrax, Dynamite, Trinity and Hobbico. Batteries that are purchased direct from Sanyo, Panasonic or Gold Peak that have no hobby industry branding are not legal. These batteries include those that are used in power tools and have a solid colored shrink-wrapping to them. Racers that still own batteries such as the Sanyo NI-CD 2000, 1400, 1700 or 1200 are allowed as long as they have the original hobby industry shrink wrap.
5. Any Tamiya Hop-Op Option and spare part is allowed as long as it is used in the way it was designed, and on the vehicle it was designed for. it is strictly forbidden to cut, mill or lighten the chassis. It is strictly forbidden to re-engineer or modify the cars in any way other than with Tamiya Hop-Ups. (This applies to all classes)
6. All bodies must be painted and must be cut along the trim lines. No extra vents or holes may be added to the body.
8. Any motor connector or direct hard wiring to the motor is allowed.
9. Any battery connector or direct hard wiring to the battery is allowed.
10. Tire conditioners are allowed on rubber tires in all classes, but may be restricted at certain venues. (some TCS host sites do not allow additives due to the track being indoors and the lack of ventilation)
11. Any modification not called out specifically in these rules is not legal.
12. All bodies must use the wings that are supplied in the kit. Mixing and matching wings between different bodies is not allowed.
13. Lightweight screws that are made of aluminum, steel or Titanium that are made by other manufactures is allowed. i.e. Any screw is legal.
14. The use of thin shims (available at most hobby stores and now made available by Tamiya) to space out the slop or play in suspension arms, steering bell-cranks and wheel axles is now permitted in all vehicles except in the spec class. Shimming the aforementioned components of the car in a way that alters the geometry of the car or its basic geometry design is not legal.
15. The use of O-Rings on shock ball ends and camber/steering links is allowed.
17. If a driver finds a loophole within the rules, that exploitation will be deemed illegal.
TL-01 spec rules (since the current 4wd off-road buggies are based upon these Tamiya chassis'
1. Chassis allowed: All TL01, TL-01 LA and TT-01 chassis kits.
2. The Only Hop-Ups allowed are:
a. Tamiya plastic oil-filled shocks
b. Ball bearings
c. TL-01 Turnbuckle steering tie rod set
d. TL-01 adjustable arm set . TT-01 adjustable arm set , TT-01 Turnbuckle steering tie-rod set
3. The Kit type closed-end-bell, silver can motor (Mabuchi/Johnson) is the only motor allowed for this class.
4. The stock size pinion is the only gear allowed for both chassis types.
5. You must run kit type tires
6. All Tamiya Spec Class cars must use stock wheels and tires.
7. Any tire insert may be used.
8. New for 2006: The aluminum/carbon center prop shafts are now allowed for the TT-01 and TL-01 based chassis
Also I just found 5 tamiya 4wd off-road TT-01 and TL-01 based kits that would be legal... all come with oil filled shocks and 2 come with a Tamiya esc....ranging from $79.99 to $105.99!! and 2 RTR's ranging from $161.99 to $169.99!!
That would get the LHS prices from between $80 and $125 for a kit and $165 to $180 for the RTRs....
Tell me that kids wouldn't dig this buggy, it looks pretty cool!!!