Tamtech LWB Chassis

Three models are equipped with the short-wheelbase Tamtech chassis. For the numbering identifying these models there is some confusion because the first series in 1986 is released for sale with a 4-digit identification code, which becomes 5 digits from 1987. The 5-digit code is the one that was most widely used in catalogues until it was finally released from the market in 1992.
In addition to this confusion dictated by the identification code, these models are available in two versions:

– a ready-to-run solution in which the package includes remote control, “C.P.R.” or “Control Processing Reveiver” on-board electronics (servo + receiver + integrated speed control), 7.2 V 270 mAh battery pack, complete chassis to be built, bodywork to be painted and stickers to be completed. In some markets the 7.2 V by 270 mAh ‘TAMPACK’ battery pack is also included, in most countries the purchase of a 12 V Tampack quick charger is suggested. The remote control is of Futaba origin in the ‘Attack’ version, includes the receiver incorporating the speed control and separately the micro servo for steering.

– only car in which the package includes complete chassis to be built and bodywork to be painted and completed with stickers.

List of models released for sale

– Ferrari Testa Rossa released for sale in 1987: code number 47005 car ready to race complete with electronics – remote control – battery and code number 48005 car only. The bodywork is red to be coloured and completed with stickers. No 4-digit code was used for this model.
– Porsche 961 released for sale in 1987: code number 47006 ready to run car complete with electronics – remote control – battery and code number 48006 car only. The bodywork is in white colour to be coloured and completed with stickers. The 4-digit code for this model is 2111 for the ready to race version and 2112 for the chassis and body only version.
– Lamborghini Countach released for sale in 1987: code number 47007 ready to race car complete with electronics – remote control – battery and code number 48007. The bodywork is in white colour to be coloured and completed with stickers. No 4-digit code was used for this model.

There are several advertisements that Tamiya or the various importers around the world have published in trade magazines, in the image below are some examples.

Other part numbers are available:

– Ferrari bodywork code number 40017

– Porsche bodywork 961 code number 40018

– Lamborghini Countach bodywork code number 40019
– remote control complete with speed control receiver and servo, Tamtech 201 code number 1101 or 45001
– 7.2 V 270 mAh battery pack, Tampack code number 5530 or 55030
– 12 V 270 mAh battery pack, Tampack Quick Charger part number 5532 or 55032
– replacement motor FK-180SH Mini-Black, part number 2603 or 40003
– replacement differential complete with sprockets, part number 2605 or 40005
– replacement rims (4 pieces), part number 2604 or 40004
– replacement sponge front wheels (4 parts), part no. 2608 or 40008
– replacement sponge rear wheels (4 pieces), part no. 2608 or 40009
– set of ball bearings part number 40012
– receiver unit with speed control code number 45008

The main features of this design are:

– transmission on the two rear wheels,
– central double-shell chassis housing the speed control receiver and steering servo,
– rear system housing FK-180SH Mini-Black motor and transmission with differential. The package includes 4 sprockets with 8, 10, 12 and 14 teeth. A higher number of teeth increases the maximum speed achieved but reduces battery life and acceleration,
– independent front suspension acts directly on the steering shaft. The package includes two sets of springs: the grey springs are the normal ones and the black springs are the softer ones. The softer springs ensure better steering responsiveness and oversteer behaviour of the car,
– The rear rigid axle suspension acts between the centre shell and the rear drive unit. The guaranteed travel is minimal, but sufficient for such a compact model,
– innovative motor speed control system via the C.P.R. control unit, which stands for “Control Processing Reveiver”; an electronic board that includes the receiver and integrated motor speed control. The control unit allows proportional movement forwards and backwards. The electronics are equipped with a safety system against short-circuiting and overheating. The safety system intervenes and stops everything when the machine is used on heavy surfaces if the motor gets too hot. It is necessary to wait for the system to cool down before it can be used again, average time 15 minutes. Surfaces to be avoided are turf, carpets and surfaces covered with fine sand; for correct operation avoid dirt accumulating on the transmission, gears and differential. The power unit is delicate and suffers when exposed to rain and water,
– the four wheels are made of sponge and are the part that wears out during use, the other parts are not subject to particular wear or breakage.

The on-off contact system is a bit complex to assemble and if the operation is not carried out in a workmanlike manner it can generate false contacts by switching off during normal operation of the machine.

The short wheelbase and long wheelbase versions of the Tamtech are completely different from each other although they take up the basic concepts, the short wheelbase being the evolution of the long wheelbase. This guide illustrates the differences between the short and long wheelbase chassis.
It is quicker to list the parts in common between the two models: rear differential, sprockets, FK-180SH Mini-Black motor, ball bearing bushings, front suspension springs, wheel hub, drive axle, CPR unit with servo and battery pack…
The scale of these products is 1/24 and all these models have very detailed ABS bodywork; the dimensions of the model are small in fact the remote control is larger than the model.
For the 4×005, 4×006 and 4×007 chassis there is the possibility of changing the distance between the front and rear axle by approximately 7 mm. The Porsche 961 model 4×006 has the shortest wheelbase ever at 97 mm. The Testa Rossa model number 4×005 and the Countach model number 4×007 have a wheelbase of 104 mm, while still remaining a short wheelbase chassis as the 4×001 chassis; 4×002, 4×003 and 4×004 have a wheelbase of 116 mm.
In the image on the left it is highlighted how to set the short wheelbase chassis with a pitch of 97 mm by installing the axle of the engine – transmission unit in the blue point and on the right it is highlighted how to set the short wheelbase chassis with a pitch of 104 mm by installing the axle of the engine – transmission group in the red dot.

To adapt the frame to the shortest wheelbase among those available, the two rear tie rods have two different positions on the central shell.

The scale of these products is 1/24 and all these models come with highly detailed ABS bodywork; the dimensions of the model are small, in fact the remote control is larger than the model.
There are several static models that have exactly the same bodywork installed on the Tamtech chassis. In some cases, the Tamtech wording is printed on the bodywork of the static version inside the bodywork. The main differences are:

– the cockpit windows are transparent in the static version and black in the Tamtech version,
– the 4 screw holes for attaching the bodywork to the chassis are only sketched out in the static bodywork,
– the hole in the bodywork for the antenna which is missing in the static version e
– some details (such as headlights, engine exhaust, air intakes) are part of the bodywork in the Tamtech version, they need to be glued in the static version

These are the static models that share the bodywork with the Tamtech model:

– Ferrari Testarossa model number 24059. The bodywork of the static version is much more detailed than that of the Tamtech. In the image on the left you can see the side air intakes of the static version which are replaced by the bars used to join the chassis to the bodywork in the Tamtech version. The static bodywork must be modified in order to be installed on the Tamtech chassis.

Porsche 961 which participated in the 24 hours of Le Mans in 1986, model number 24320 from 2011 and 24072 from 1987, has the exact same bodywork as the 4×006 and has two holes on each side to secure the bodywork to the frame. In the construction manual of the static version (first image on the left below) you can clearly see the two holes on each side in the bodywork at the height of the two doors. In the static version there are four flat-headed pins which two on each side close these holes (central image below). These holes are in the same position in the bodywork of the Tamtech and are used for the screws of the bodywork – frame locking system in the Tamtech version (image on the right below); the only modification to be made is the antenna hole.

– there is no static equivalent of the Lamborghini Countrach 5000 quattrovalvole. There are several similar models, but there is no evidence of attempts to install these bodies on the Tamtech chassis. If the wheelbase of the Lamborghini LP500 S model number 24306 is correct, the probability of being able to install a static body on the Tamtech chassis is high.

It is possible to adapt many of the static bodies to the Tamtech chassis. This guide shows how to assess the technical feasibility of installing a static body on a Tamtech chassis.

Tuning

To improve the performance of the model you can:
– change the steering tie rod system by installing metal arms that are stiffer than plastic ones to improve steering precision
– install aluminum heat sinks to better cool the motor and increase performance
– change the front suspension springs. The package includes two sets of springs: the gray springs are the normal ones and the black ones are the softer ones. The softer springs guarantee better steering response and oversteering behavior of the car. It is possible to find springs on the market that have different stiffness.
– change the pignon. The package includes 4 pignons of 8, 10, 12 and 14 teeth. A higher number of teeth increases the maximum speed reached but reduces the useful life of the battery and acceleration,
– change the FK-180SH Mini-Black series motor with a more powerful one in the FK180 or FF180 series

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