As a fervent Hotshot fan I thought I would compile this compendium for any interested members to show the subtle but apparent differences on the first four Tamiya ‘'shot'’ kits. I am not an authority on this of course but most of what I have written is based on my experience, comparing the kits I have plus some virtual brain storming via email with a few other TC members (c_smith, Wandy and Crash Cramer). As far as I know this is accurate, but of course if anyone else has something to add, please PM me or add a comment here and we can get a discussion going.
I will consider the Mk1 and Mk2 Hotshot, the Supershot and the Hotshot II where a comparison is relevant and any subsequent differences/amendments apply. This I hope will help identify and distinguish the parts for a person looking to perhaps purchase an original ‘shot’ model or for a restoration project where they may be unaware of the things to look out for.
I will start at the back, this is where the least differs between the four.
The Hotshot (HS) Mk1 and Mk2 rear arms, top and bottom are identical. The Supershot (SS) rear arms to the lay person are identical to those of the HS (same design with the circular holes (upper), triangular (lower)) but on the lower SS arms Tamiya decided to include a small protrusion in the mould which acted as a guide for the lower bracket of the H.P dampers. ** I have been told by Tamiya that the original HS mould was amended for the SS but modified arms (with this protrusion) were included in Hotshot kits made after March 1986 (release date of the Supershot)** although I have had many nib Hotshot kits pass through my hands over the years, none have had these arms included in the kit.
The Hotshot II (HS2) has triangular holes in both the upper and lower arms instead of circular. Also the lower arm is a different shape, reflecting the position of the C.V.A shocks to the front.
Perhaps also worth mentioning are the rear uprights, again the HS (Mk1/Mk2) and SS are identical where as the HS2 uprights differ. They are distinguishable from one another again because of the offset position of the he C.V.A attachment.
The HS resistors are bespoke to this kit and two variants were manufactured. Aesthetically they are pretty much identical, the material, the crenulation in the heat sink body design and the use of black FRP but one type was a ‘‘free-floating’’ version (as it has come to be known on TC) and the other, a glued version. The Mk1 HS only had the free-floating type (this is the earliest design) but the Mk2 kits came with both types, earlier Mk2 kits having the free-floating resistors and later models, the glued versions. The SS resistors are also unique to this particular kit and are easily recognisable being square this time with separate white FRP resistor plates. The HS2 uses a different resistor again, this time a single three pronged resistor with a vented cover. The MSCs too reflect these resistor changes and all are unique to each respective model.
Another small difference and perhaps insignificant but I feel should be mentioned nonetheless is with respect to the rear gear box guard found on the HS. This was only to be found on this model and only on the Mk2 HS. There was no transitional period between the Mk1 and Mk2 models.
There also seems to be an error with the diagram in the Mk1 manual. The Mk1 E10 part has three holes like the later Mk2 Hotshot and Supershot, but the manual only shows two holes.
The first difference is with respect to a recess on the lower arms for one of the 2mm screws. The purpose of this was to prevent (reduce) the wheel rub which was attributed by this screw when the suspension arm moved through a certain plane of motion. There was no recess to be found on the Mk1 and Mk2 HS arms but this recess was added to the HS mould for the production of the SS (and subsequently for the HS2 as the mould was further amended).
Continuing with the HS front arms, these are unique to this kit and differ to both the SS and HS2. The second noticeable difference is the inclusion of the triangular protrusions on both the upper and lower arms. Although these protrusions were also found on the SS arms, the manual instructed the owner to remove them from the lower arms specifically. From a distance therefore these HS/SS arms could be mistaken for each other as the upper arms are identical for both models and the lower arms both have the tell-tale protrusions as well. The way to distinguish the two (they are sold as a set, upper and lower) is to focus one’s attention on the lower arms and in particular to look at the design of the arm itself. With the HS arms it had four triangular holes as part of the design, on the SS however it only had three, the fourth replaced instead by a screw hole. This screw hole is for the attachment of the H.P suspension lower damper bracket. Of course, this is by the by if your HS was made after March 1986, then SS front and rear arms would be period correct!
If we now consider the HS2 arms, again the upper are identical to those of the HS and SS and are also sold as a set. The way to distinguish these F parts is to once again concentrate on the lower arm. With the HS2 lower arm Tamiya saw fit to alter the design and produce the arm without the triangular protrusion, this has been completely omitted from the moulding process. The arm still has the same three triangular and one screw hole design configuration plus the recess but is now obvious to determine from a SS lower arm.
Differed on three of the four models. Identical in appearance for the Mk2 HS and SS however the uprights for the Mk1 HS are ever so slightly different. These are unique to this kit and the difference lies with the screw thread diameter of the 8mm ball connectors and the part of the arm into which these are screwed. Because the screw thread and seat of the ball connector are narrower, this is reflected in the design of the arm itself (as can be seen in the picture). The HS2 arms differ again in design.
8mm ball connectors
Type specific and aluminium for the Mk1 HS. On initial appearance, they look the same as those of the Mk2 and Supershot but the screw thread (M3) is significantly narrower. The Mk2 HS, SS and HS2 ball connectors are identical in shape and screw thread (M4) diameter except for the material used. Aluminium for the Mk2 HS and SS so appear dull in comparison to those of the HS2 where they were changed to chrome plated brass and thus appear shiny.
The HS Mk1/2 were the same design and found only on this model. The front (F) and rear (R) shafts consisted of steel dog bones attached to hollow aluminium tubes, they also differ in length, the fronts being slightly shorter and denoted by two thin lines engraved into each end of the aluminium part of the shaft. Please note, the Mk1 and Mk2 Hotshot F shafts differed, the Mk1 drive shafts only had a single line engraved into each end of the aluminium tube, the Mk2 Hotshot had two. This is another unique feature for the Mk1 Hotshot and something to consider.
'The SS saw the first design change to a single piece of shaped metal and was to be seen across all subsequent 4WD models. These shafts also differed slightly in length but were denoted this time by colour, brown for the front and black at the rear. The HS2 was the first shot kit to use unilateral shafts, identical to those of the SS rear shafts. The unified shafts came about because of the slight design change to the steering arm, the ball bearing position had been offset by ~2mm each side allowing for the longer shafts.
Front gear box
There were two variants of this. The Mk1 HS version was unique and used only on this kit. It had recesses to accommodate the flanged bumper stay (also unique to the Mk1 HS) and did not include the four small strengthening ribs (two each side) that were later added for the Mk2 HS, SS and HS2 gear box. Also the furthest most retaining screw on the gear box (closest to prop shaft) has no recess, this was also added for the Mk2 HS and subsequent SS and HS2 gear boxes.
Unique for the Mk1 HS and has two small collars which fit specifically into the recesses within the Mk1 gear box. It is also attached from each side with separate 3mm round head screws. The Mk2 HS/SS/HS2 bumper stay was simplified to the current design with one 3 x 27mm round head screw and flange nut to hold it in place. Also the material has changed, it was aluminium for all except the HS2 where it was changed to brass.
The Mk1 HS bumper is iconic and identical to the box art. Having a higher rake and the three tell-tale lightening holes. It was made out of a very soft, flexible plastic (Nylon). The bumper design was changed for the Mk2 HS, hence the sobriquet and was to be used on the SS and HS2 as well. Lower rake and a much tougher plastic used (Polycarbonate). There is a very subtle difference between the HS/SS bumper and the HS2 bumper, the centre screw hole in the middle of the underguard, that attaches this to the bumper stay. On the HS/SS, this screw hole is circular but on the HS2 this hole was changed in the moulding process and is now slightly elongated. Incidentally, it is this HS2 bumper that you find on the re issue Hotshot so make sure a genuine vintage C parts sprue is actually vintage by checking this screw hole unless the seller describes it as a HS2 one of course!
One additional point to note is with regards to the body mount on the SS. This particular mount is unique to this model and found on no other Tamiya buggy. If buying a used SS, make sure this part is included/fitted.
The reissue Hotshot
Food for thought and one of the reasons I wrote this is with respect to the re issue Hotshot. The F and R arm moulds used for this model are a combination of HS2 front arms and Supershot rear arms. These parts of course can still be used respectively but depending on your stand point, this could affect the vintage integrity of your model. A sure way to tell if the 2007 arms are legitimate originals is to look at the sprue (assuming they are still attached to their sprue) for a flattened square piece of plastic around the centre. The original arm sprues do not have this and is the bit to look out for. The re issue parts still have RCC Hotshot stamped on them and so is no indication of the part's real age.
For anyone interested, I recently managed to speak to Tamiya directly about the Hotshot. I actually had about 50 questions I wanted to ask but unfortunately as most of these were about the Mk.1 Hotshot, Tamiya could not divulge certain details because they pertained to internal developmental processes. They did however confirm a few things to me. An issue that has popped up many times before is with regard to those infamous gold wheels, were they ever actually included in the Hotshot kit? Well, the answer is no, they were never included in retail kits; all were white. The gold wheels were retained on the box art as it depicted metal-plated wheels as seen on (in this case, fictional) real-life cars. The use of a centre prop shaft was also chosen (over an alternative) because again, they wanted to keep it as realistic as possible to a real car. This I found really interesting, there were actually a number of candidates put forward with respect to the model name during the development stages. The original front-runner was “Holeshot”, but eventually opinion began to settle upon the “Hotshot”. At least it was always going to be coloured red, there were no disagreements on this apparently. Three other designs were also put forward before they settled on the design that we all know and love to this day. And for those desperate for a Mk1 Hotshot, no spare parts were ever released for the early model. All in all, the development of the Hotshot took around 1 year before it was released.
Written by TC member Rosey and reproduced here with kind permission