Astute

Astute is named after the first model released for sale using this chassis:

– Astute, model number 58080 put on sale in 1989 and available on the market until 1992,
– Super Astute, model number 58097 put on sale in 1991 and available on the market until 1993,

This chassis represents Tamiya’s clear attempt to take the lead as a manufacturer of two-wheel drive buggys not only for fun, but also for competition use. This project has the same aim in the 2WD market as the Avante chassis has in 4WD: Tamiya wants to excel in technical solutions even in two-wheel drive models.

The main features of this model are:

– rear-wheel drive,
– four independent adjustable suspension with CVA series shock absorbers,
– chassis consisting of an FRP plate, which stands for ‘Fiber Reinforced Polymers’, 2.5 mm thick, which lowers the centre of gravity,
– easy access to the gearbox to change gear ratios or carry out maintenance, and
– complex bushing system to preserve the suspension arms from wear.

In keeping with Tamiya tradition, the Astute chassis has evolved from the first to the second model released for sale; Tamiya has not changed the name of the chassis, but there are so many differences that the only common parts are

– parts D, E and P
– most screws, bolts, nuts and washers: A, B, C, D and E screw bags
– most bags: Ball Connector Bag, Damper Bag, Metal Parts Bag, Shaft Bag, Metal Bearing Bag, 730 Metal Bearing Bag,
– drive axles and constant velocity joints with wheel hubs
– body, wing and underbody

Astute, like Avante, is also too complex and difficult to adjust to maintain neutral behaviour. The weight is very much concentrated on the rear, which makes it easier to drive on straights and fast bends, but understeer takes over, making the car difficult to drive in tight bends.
What was developed in the Astute was later corrected in the Super Astute. Let’s see what the main differences of these two models are in comparison:

– the chassis is FRP for both models; but the chassis has a different geometry of two holes as the battery pack is transverse in the Astute and longitudinal in the Super Astute. Left image is the frame of the Astute

The two frames are identical except for the holes required to fix the battery longitudinally (highlighted in orange in the picture below).

The less-recessed position of the battery pack allows the Super Astute to have a less understeerful set-up.
Battery replacement is certainly quicker on the Astute models, but the optimisation of the Super Astute’s chassis balance is evident: understeer almost disappears. Left image is the battery position of the Astute and right image is the battery position of the Super Astute.

– the lower window at the height of the gearbox allows the gears to be inspected without removing the gearbox from the gearbox.
On the Astute there is an adjustable ball differential that becomes a classic gear differential in the Super Astute.
In the Astute, the differential action was adjustable by adding or removing the spacers that have the initials “SC7” (highlighted in red in the picture). The differential on the Super Astute is an evolution of those used to date on other models, the satellites are now cylindrical. Left picture is Astute’s ball differential and right picture is Super Astute’s gear differential.

– TTC, which stands for Tamiya Torque Control, is introduced for the first time on the Super Astute to improve the road holding of the rear wheels,

– the lower front suspension arms have changed shape, but the dimensions of the attachments are the same. The shape of the arms slightly changes the set-up of the car and its wheelbase. Front suspension lower arms, left image is the suspension of the Astute and right image is the suspension of the Super Astute.

– The lower arms of the rear suspension have changed shape, but the dimensions of the attachments are the same. The shape of the arms slightly changes the set-up of the car and its wheelbase. Rear suspension lower arms, left image is the suspension of the Astute and right image is the suspension of the Super Astute.

– In the suspension mounts of the Astute and Super Astute, Tamiya introduces bushings that are designed to wear out and be replaced when necessary. This fine technological solution has an additional weight that is not balanced by the advantage. In the picture the bushings are highlighted in red for the Astute model, the same bushings are also found in the Super Astute model.

– on the Super Astute a front reinforcement was introduced on the shock absorber tower (highlighted in blue) to prevent breakage, this reinforcement was often retrofitted as an aftermarket accessory on the Astute

– i fuselli dello sterzo diversi nella forma e dimensione, in rosso il modello Astute e in blu il modello Super Astute. Il sostegno a C è molto simile nei due modelli anche se è individuato da due codici diversi sigla “C1” per la Astute e “BX1” per la Super Astute; in arancione il modello Astute e in azzurro il modello Super Astute.

– the front suspension arms are 4 millimetres in diameter in the Astute (left) and 3 millimetres in the Super Astute (right).

– The Astute’s rear suspension system (pictured left and centre) is innovative in that it features an additional tie rod: the hub’s tie rods form a Z and this geometric configuration increases toe-in when the shock absorber is compressed. This solution is abandoned by the Super Astute, which adopts a more conventional single upper tie rod configuration (pictured right) that is easier to calibrate.

Astute’s rear hub adjustment system allows you to adjust the toe-in of the rear wheels. The rule for rear-wheel adjustment is more toe-in for handling and less toe-in for better stability on the track. Excessive positive or negative toe-in leads to abnormal tread wear, increases drag, and can lead to instability.

– The shape of the shell protecting the pinion and gear is different, left image is the Astute shell and right image is the Super Astute shell.

Re-release

Re-release models take up the original Astute chassis with minor updates:

– Super Astute, model number 47381 put on sale in 2019 and available on the market until 2020.
Among the updates released is an evolution of the TTC (Tamiya Torque Control) system.

Evolution

The Astute chassis evolved into the MadCap chassis, which is on the market with the following models:

– Madcap, model number 58082 put on sale in 1989 and available on the market until 2002,
– Saint Dragon, model number 58083 put on sale in 1990 and available on the market until 1992.

The Astute frame shares the design philosophy with the Madcap frame. The Madcap frame is a further simplified evolution of the Astute model; here are some important notes:

– the Madcap frame takes the shape of the Astute frame, but is a plastic tub.
– the suspension system has the same geometry based on four oil-free shock absorbers
– differential housing is the same between Astute and Madcap-Saitn Dragon (identified by the initials “A4” in the picture, on the left the Astute model and on the right the Madcap model) differs only in the motor mount, which is metal in the Astute and plastic in the Madcap-Saitn Dragon (identified by the initials “F1” in the picture)

– the Madcap does not have bushings for the suspension arms; after field testing with the Astute chassis it was agreed that it is better to replace the suspension arms when the bindings wear out than to have this added ballast weight
– the suspension mounts are the same size, so it is possible to install Madcap suspension on the Astute and vice versa. The lower suspension arms on both the front and rear (on the left the Astute’s B side and on the right the Madcap’s) have different shapes, but the dimensions of the mounts are the same.

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