Hot Shot

This family is named after the first model that was released for sale; Hot shot is an iconic name for Tamiya, it marked a turning point in the world and in the off-road car market. It was the first all-plastic car with four-wheel drive and independent suspension. Two developments were then made from this model and even today (2023) it is hard to count all the reissues: 5 reissues in total of which 3 for the Hot Shot, 1 each for the Super Hot and the Hot Shot II. There are three models that head this family and were released individually a year apart from each other:

– Hot Shot model 58047, released to sale from 1985 until 1987
– Super Hot model 58054, released to sale from 1986 until 1987
Hot Shot II model 58062, released to sale from 1987 until 1991

For the Hot Shot, two evolutions identified as MK1 and MK2 can be distinguished.

The commercial success of this product seems to have no limits and memorable photos of Ayrton Senna holding a Hot Shot in black John Player Special livery can be found on the web. In this case, the model’s driver’s helmet took the colours of the famous F1 driver’s (yellow with a green stripe and a black stripe).
Tamiya dedicated 4 full pages to this model in the 1985 catalogue out of a total of about 64 pages. Of the 4 most important pages of the catalogue, the cover and back cover are dedicated to the Hot Shot.

There are several advertisements that Tamiya or the various importers around the world have published in trade magazines, in the image below we show two cases for the Hot Shot and one for the Super Hot.

Tamiya included an alternative body colour for the Hot Shot in the 1985 Guide Book.

Pictured from left to right, the structure of the machine consists of:

– Front assembly comprising the differential (nylon gears with zamak satellites), suspension and front bumper
– Central part which is a double shell housing electronics, speed controller and battery
– Rear assembly comprising the differential (nylon gears with zamak satellites), motor, suspension and speed control resistors

Although the model is the first one made of black plastic, some parts are made of carbon (such as a V-shaped joint for the battery); the basic plan was to make a very light model.
The body is lexan complete with a rear wing. The driver was an integral part of the central upper shell. The cockpit roof is made of sheet metal. The suspension system with independent arms and four-wheel drive ensures optimum road holding, allowing it to tackle any terrain. The front and rear suspension is equipped with a torsion bar, an absolute novelty that, together with the high suspension travel, makes this machine even better at absorbing rough terrain. Movement to the four wheels is provided by a hardened steel shaft with hexagonal brass ends positioned centrally, the shaft passes through the electronics box. The brass ends were designed to wear before the satellites of the two differentials, which were made of metal. This shaft is maintenance-free and virtually indestructible, differing from the chain or belt used on equivalent models from other manufacturers in recent years.
At the time it was released for sale, it was the easiest car to drive that many managed to make competitive on dirt tracks. The two front and rear assemblies were also used unchanged on other models such as:

– The Boomerang model 58055,
– The BigWig 4WD model 58057 and
– Super Sabre model 58066

These models have had several reissues, so it is easy to see that the design of these two parts has been an incredible commercial success. This explains why there is an abundance of spare parts on the market as many parts are common to other models: they have been produced for years and/or are still in production.
The part most prone to breakage and wear is the front part:

– the bumper breaks if there is too much impact,
– the front gearbox or the suspension arms themselves break in the event of too strong an impact. The suspension linkage tends to wear – wear by increasing the play between the arms and the chassis

The three models in this family are characterised by many details that differentiate them from each other, here is a list of the macro common parts:

– off-road tyres of different sizes at the front and rear. The factory tyre blocks are oval, the set for the front wheels is SP-5233 and the set for the rear wheels is SP-5234. There is an accessory set with pyramid-shaped blocks for more grip on the ground, but at the same time they wear faster, the set for the front wheels is the SP-5235 and the set for the rear wheels is the SP-5236.

These were the first tyres in which the shoulder of the rubber was really very low and not high as it is today. The tyre completely loses its function of absorbing bumps and is only built to ensure the best traction for the model. This was also an aspect that set the standard from this model onwards.
– lower shell of the electronics box,
– gear system – front differential, unless there are minor differences they are interchangeable between the 3 models,
– cockpit roll bar,
– metal central shaft linking rear and front differential common to Hot Shot and Super Hot

All other parts have had minor updates that differentiate them from one model to another.

Hot Shot
Being Tamiya’s first off-track car, a lot of precautions were taken in the design that made it an expensive product, many expedients that were taken in the design phase to reduce maintenance and the possibility of breakage were found to be excessive. In the following models, precautions were then taken to reduce costs without reducing performance, often these interventions reduced the weight of a model that was already much lighter than the previous ones in Tamiya’s catalogue.

The parent model can be recognised by these distinctive elements that are recognisable at first glance

– red body + wing,
– number two red shock absorbers; one for the front suspension and one for the rear suspension. The installation of the shock absorber and the mechanism to transfer movement from the arms to the shock absorber itself is a masterpiece of engineering. There were probably a thousand ways to do it more simply, but that was the most spectacular solution,
– number two ceramic resistors of the mechanical motor speed control have a cylindrical shape and are unique for this model, they are installed to the left and right of the rear above the gearbox and under the rear wing behind the driver’s cockpit. As a heat sink they have two characteristically finned aluminium cylinders, they look like two small bells positioned in the best spot to receive cool air when the car is in motion. Be warned, however, that they do get very hot, not least because there is a sticker saying ‘CAUTION HOT’.

However, a closer look at the model reveals many other differences from the other models, and the Hot Shot itself was produced in two versions, Mk1 and Mk2.
If you have the instruction manual at the bottom right you will find the date of the versions: Mk1s are marked 8503 or 0385 (March 1985) while Mk2s are marked 8504 or 0485 (April 1985).

Starting from the front and proceeding to the rear of the car, a first difference between the Hot Shot (pictured left) and the Super Hot (pictured right) can be found in the front bumper and bumpers. The bumper and bumper for Mk1 was made of very flexible plastic and was characterised by three holes in the centre. With the Mk2 version, the plastic was changed, making it more rigid, and these three holes were removed. In the picture you can see from left to right the Hot Shot Mk1 with the three holes the Super Hot without holes and the Hot Shot II without holes.

Another difference is in the front axles of the suspension drive. The axles of the Hot Shot are unique in that they consist of a metal tube where the two joint pins are inserted. The difference between the front and rear axles is their length, the front ones being shorter. To distinguish them from the rear ones, signs have been inserted at each end in the Mk2 version. It is certain that there is a mark at each end. It is likely that in the Mk2 version two marks were inserted for each end at a later date. It is possible to make a front axle from a rear axle by shortening it. In this case it is difficult to give a precise classification between Mk1 and Mk2.

Another difference was in the two lower front suspension arms.
The 8 mm diameter ball joint has two different thread diameters; in the Mk1 the thread is a smaller M3 while it becomes an M4 from Mk2 onwards (thus also on the Super Hot and Hot Shot II).

Also at the front for Mk1 is a gearbox that is different from that later adopted from Mk2 onwards. The shell does not have the two reinforcements that were added in later moulds. The hexagonal-section pin for attaching the bumper has a different shape because in the Mk1 it has two cylindrical sections at both ends, which also means a different housing in the gearbox. This pin is secured with two 3M screws, one on each side. In contrast, from Mk2 onwards this pin is not threaded and is secured with a 3M x 27 screw and nut.

In the pictures below, the parts for MK1 are on the left and the parts developed for the following versions are on the right:
– shell without the two triangular reinforcements for Mk1 and with the two reinforcements for the following versions,
– hexagonal pivot with reinforcements on both sides with a circular cross-section for Mk1 and without for the following versions,
– left and right front shell with slot to accommodate the circular section of the front pin for Mk1 and without for the following versions.

Having finished analysing the mechanics, let’s move on to the electrical part; a difference that can only be noticed by having the machine in your hands between the Mk1 and Mk2 models is in the heating elements. The two electric resistors with their particular shape are distinctive for this model and consist of these parts

– black FRP plate to fix the resistor to the frame,
– laid resistor and
– aluminium heat sink

In the Mk1 version, the resistor was free to move inside the heatsink; in the Mk2 version, while maintaining the same shape and parts, the resistor was locked inside the heatsink. In the central image below you can see a resistor that is not locked inside the bell, this is the configuration of the Mk1. In the picture on the right you can see a 5237 set which is the replacement for the motor speed control for the Hot Shot still new and packaged; you can see that the ceramic resistor is blocked by some kind of solid black paste, this is the configuration of the Mk2.

Super Hot
The Super Hot was the first development of the Hot Shot, and the interventions made all had the same objective: to optimise the economies of scale in the production of the model by simplifying what had been designed to avoid breakage and which turned out to be far too much in the Hot Shot. A greater focus on costs corresponded to a reduction in weight and so commercially it was a success because the Super Hot was presented as a higher-performance evolution of the Hot Shot. In fact, the price of the new set was higher than the starting price, masking the cost reduction in increased performance and handling: a typical example of a marketing success and an excellent advertising campaign.

It is possible to obtain a Super Hot by changing these parts into a Hot Shot:

– Body by changing from the red one to the silver one which also has a slightly different shape being more wrapping around the chassis, set number 5261,
– 4 rims, set number SP-5266,
– front and rear suspension system with yellow double C.V.A. shock absorbers, set number SP-5276 or 50276. Installation guide for the front and rear dual shock system to convert a Hot Shot into a Super Hot,
– mechanical speed control system complete with the two ceramic resistors. Expensive bellhousing – bedded cylinders are removed in favour of parallelepiped-shaped resistors, set number SP-5282, and
– 4 drive axles become lighter – thinner and in one piece (in the picture on the left the axles of the Hot Shot and on the right those of the Super Hot), front set number SP-5298 and rear set number SP-5299 and
– Techni Power RS-540SD motor

For this model, the underbody protection was released for the first time, the function of which is to preserve the car from breakage due to impacts with the ground after jumps; set code SP-5275. This set obviously fits all three sisters.

Let’s exclude the obvious differences in body shape, rear wing and cockpit roof. Starting from the front and proceeding towards the rear of the mechanics, a first difference between the Hot Shot (pictured left) and the Super Hot (pictured right) can be found in the two lower arms of the front suspension. In the picture on the right you can see that there are the two wings coloured blue, in the instructions of the Super Hot it says ‘not used’ or ‘cut away’. This implied that this part could be worked on with a file or sandpaper to remove them. In fact, with the wheels fully steered when compressing the suspension, these fins could interfere with the two front shock absorbers. There is another obvious difference between the version of the Hot Shot and the Super Hot, the hole design differs in the lower part of the picture which is triangular for the Hot Shot and circular for the Super Hot. The circular hole was later adopted for the Hot Shot II. The circular hole helps to correctly install the screw that holds the front shock absorber plate.

There is a difference in the components of the Hot Shot and the Super Hot+Hot Shot II that is really not very visible and can only be detected after having the model in hand and disassembling it. There is a triangular-shaped metal base which is present in the Hot Shot (pictured left) and is completely absent in the Super Hot and Hpt Shot II (pictured right).

A clearly visible difference between the Hot Shot and Super Hot is how the rear shock absorber is fixed, which is single on the Hot Shot and double on the Super Hot. The picture on the right shows the rear shock absorber system of the Hot Shot, while on the right is the rear shock absorber system of the Super Hot.

Having finished analysing the mechanics, let us move on to the electrical part; beware that the differences indicated may not apply if the model you are analysing is equipped with electronic speed control. The speed control system consisting of the resistors and the rheostat differs from model to model, although it takes the same concept and develops it. The rheostat on the Hot Shot is the simplest and does not have any hooks to hold the cables going to the motor, pictured on the left is the Hot Shot version and on the right the Super Hot one.

The location of the electric motor speed control resistor for the Super Hot is at the rear of the car below the spoiler behind the driver’s cockpit. The speed control system has two resistors as for the Hot shot version, but the shape was markedly different. These resistors are also only typical of the Super Hot version. Pictured on the left are the two resistors of the Hot Shot and on the right the Super Hot.

Hot Shot II
Hot Shot II was developed by building on the experience of its two previous sisters. Again, changes were made to reduce costs and not to reduce performance. In the meantime, many competitors have appeared on the market that have more attractive body and are faster. Of the three sisters, it is the one that is sold the least and has probably sold the least, again you would have to have access to information – Tamiya archives to confirm this.

Let’s exclude the obvious differences in body shape, rear wing and cockpit roof. Starting at the front and proceeding to the rear of the car, a first difference between the Super Hot (pictured left) and the Hot Shot II (pictured right) is immediately found in the front bumper. The hole that attaches the front bumper to the gearbox is oval instead of round. On the left the version for Hot Shot and Super Hot, on the right the version for Hot Shot II.

The hexagonal-section pin for attaching the bumper in the Hot Shot II identified as the ‘bumper stay’ retains the simple shape without the circular-section collars, but changes its material from aluminium to brass.

The battery lock plate is the same for the Hot Shot and Super Hot, it is V-shaped and made of carbon. It allows the battery to be removed from underneath the machine. With the Hot Shot II, a rear bumper was inserted to replace this plate. The bumper is efficient, but no longer allows the battery to be removed from underneath, leaving only the side option open.

Another difference is in the suspension axles, which are all the same length. There has been a change in the bearing housing in the steering that has allowed the two front axles to be the same length as the rear. This modification is not the only one in the steering, later we will see another one concerning the shape of the drilled arm for the steering tie rod.

Another difference is in the two lower arms of the front suspension. This part has been changed in all three versions. In the Hot Shot the two wing-protuberances were present, in the Super Hot they were present marked ‘not used’ – ‘cut away’ and finally in the Hot Shot II the casting of the arms was changed to remove them.

A further difference can be found in the shape of the steering arm; on the left is the model for the Hot Shot and Super Hot while on the right is the model for the Hot Shot II. The spherical pin with a diameter of 8mm retains an M4 thread as in the Super Hot and Hot Shot Mk2.

A further small difference is the 8 mm diameter ball joint. For the Hot Shot and Super Hot Shot models, the joint is made of satin-finished aluminium, while for the Hot Shot II model it has become chrome-plated brass.

With this version, a modification was introduced in the upper shell of the electronics box, which has an inspection hatch. The first aim was to simplify access to the electronics box; in the first models it was necessary to unscrew 6 screws, which was not easy. The installation of the on-off switch also changed. It is no longer fixed on the upper shell, but on the underside with a metal bracket that screws into the lower shell with two screws. Obviously, the shape of the lower shell changes with the addition of the two screw holes.

It completely changes the drive axle between the front and rear differential units. With the Hot Shot II, the hexagonal coupling that characterised the Hot Shot and Super Hot is completely lost and becomes a simple ring machined into the drive axle.

As can be seen at a glance, the red rear C.V.A. shocks are installed in the suspension part and this has resulted in a change in the design of both the upper and lower suspension arms. On the left you see the suspension arms from the Hot Shot and the Super Hot, while on the right you see the arms from the Hot Shot II. The version of the Hot Shot and the Super Hot also differ in the circular holes in the upper arms.

The different suspension positions result in a different way of attaching the shock absorbers to the rear gear assembly. On the left you can see how the shock absorbers are fixed in the Super Hot and on the right the Hot Shot II.

There is also a modification in the two rear arms with bearing housing, on the left are Hot Shot + Super Hot and on the right Hot Shot II.

Another difference that is unique to the Hot Shot II is the shape of the four plates for attaching the wheels, in the Hot Shot II they are star-shaped as opposed to the triangular shape they have in the Hot Shot and the super Hot.

Having finished analysing the mechanics, let’s move on to the electrical part; beware that the indicated differences may not apply if the model you are analysing is equipped with electronic speed control. On Hot Shot IIs, it is not uncommon to find electronic speed controllers installed to replace the mechanical ones and their parts (ceramic resistance). The Hot Shot II is equipped with the latest version of motor speed control, which differs in the hook that blocks the cables going to the motor and the single electrical resistor. In the Hot Shot II the hook is integrated into the servo control arm and not screwed in as it was on the Super Hot. The photo shows the different type of hook on the Super Hot on the left and the Hot Shot II on the right.

The location of the electric motor speed control resistor for the Hot Shot II is at the rear of the car below the spoiler behind the driver’s cockpit. The speed control system of the Hot Shot II uses a single resistor, which in shape resembles that of the Super Hot, but has three connectors instead of two.

Evolution

Front differential-gear system with its double shell, rear differential-gear system with its double shell, suspension arms, front-rear drive axle of the Hot Shot chassis were used in models released for sale later:
– The Boomerang model number 58055 released for sale in 1986 and available on the market until 1991; Boomerang chassis
– The BigWig model number 58057 put up for sale in 1986 and available on the market until 1991; BigWig chassis
– Super Sabre model number 58066 put up for sale in 1987 and available on the market until 1992; Boomerang chassis

Re-releases
As of today (2023) there are several re-editions of these models: 5 re-editions in total of which 3 for the Hot Shot, 1 each for the Super Hot and the Hot Shot II. The reissues feature the improvements that have been introduced over the years, the main ones being:

– revised front suspension lower arms,
– upper electronics shell with inspection opening,
– 2 x front gearbox shells and 2 x rear gearbox shells modified to install E-shaped clips instead of C-shaped clips for locking the gear box joints,
– different drive shaft between rear and front gearbox and
– front shock absorber

All reissues include an electronic speed controller ESC.

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