Kyosho Turbo Scorpion – Short and Low build

[Lumikko]

I’m building a Turbo Scorpion for the sake of tinkering and perhaps some racing in a 13.5T stock buggy class (or vintage, if available).

This documentation will be far from step-by-step stuff but I’ll try to keep it comprehensible.

The local track is astroturf so I’ll have to do funny stuff with the setup to make it work a little better. Adjusting the suspension and steering is a jog for the brain.

As an aesthetic choice, I bought two sets of black shock plastics for the Optima to replace the stock red ones. The part trees the same, just a different color.

I didn’t realize the shock ends of the Turbo Scorpion don’t come off the shock plastics tree but they are a different part LA43. I put the black ball ends on the shocks and used the red ones in the front linkage. I’ll replace the ones on the control arms with black ones later.

The plastic side of the diff had a tight fit to the bearing. I took off some material to make the bearing fit a little easier.

I also shimmed the outdrives and used 0.35 mm of shims on the metal side of the diff to remove sideways play and to get the diff exactly in the centerline of the chassis.

There will be lots of grip so I’m pushing the weight bias forward. I cut up the battery compartment so I can run a shorty pack all the way forward and bring the ESC also forward and lower. I transplanted one piece of the tub as a stopper for the shorty pack.

That’s all for now. I’ll add warm white LED lights as a finishing touch but there’s still a long way to go.

 

[9x19]

Awesome project!

 

[Lukedavis]

Nice Job!

 

[WickedFog]

Nice. How did you like assembling the front and rear suspension? Pretty slick the way it all works huh?

 

[Lumikko]

Nice. How did you like assempling the front and rear suspension? Pretty slick the way it all works huh?

It was certainly interesting!

I have lifted the inner mounts with 2 mm spacers to reduce camber and there’s a regular Scorpion gearbox mount plate in the mail to move the motor and gearbox 10 mm forward while retaining the long wheelbase so there’s still work to be done in the back.

In the front, the carbon shock towers are the flimsiest I have ever seen on an RC car. They would probably not break easily but I’d rather not have two leaf springs affecting my front shock game. At this point, I wonder if they are even meant to be used on their own or sandwiched with the stock towers though I’m baffled what the point is then.

To reduce the enormous amount of bump steer, I have lowered the servo saver by placing a washer underneath its retaining clip but it made the cap screw for the ball hit the front suspension shaft. So I took it out, countersunk the hole from below and fitted a flat head screw.

You might have noticed the turnbuckles on the upper control arms. They are from a DR10 sway bar kit I had handy and allow me to tune the caster gain more easily.

Another chore of the day was to ensure the servo doesn’t shift around so I put those brass sleeves you get with every servo to good use:

 

[Lumikko]

Time to hack some scrap plastic from an Ikea cabinet to make an ESC tray!

Drilling inside the battery compartment was a bit tricky. I turned the drill bits by hand and used multiple sizes to reduce the chip size.

The M3x5 screws are not the sturdiest option but the battery door will support the tray from below and the hole directions prevent each screw from pulling out of the thin plastic.

I got the orientation and design of the tray right so the sensor wire port is accessible without removing the ESC.

 

[Lumikko]

Here’s a shot of the camber adjustment spacers. I chose a large outer diameter to ensure support for the mounts.

The arms had quite a bit of lateral play that I reduced with 0.3 mm shims between the arms and mounts

 

[Lumikko]

I got the regular Scorpion gearbox plate yesterday. There was a heavy discount on this old one as the current part is SC212B. No idea what the difference is, probably nothing major.

The long and short plate really are the same part except for the gearbox and motor cage holes being moved 10 mm towards the rear.

No drama was involved in the swap. Even the shocks mounted behind the tower without issues. I flipped the plastic bushings around but they fit the regular way just as well.

I think the wheelbase extension of the Turbo Scorpion is a very good change to the car but the original gearbox position is better for weight distribution and looks in my opinion.

Then steering could use ball bearings and this Team Durango spare part looks like it could be the steering post. I bought it for one buck from a clearance sale.

I also added 0.2 mm shims above the steering knuckles to take out the vertical play and have something in between the die-cast knuckle and the jam nut that holds it in place. A later post will have a detailed breakdown of every shim I used around the buggy.

I’m starting to question the comments about these Legendary series kits being refined Swiss clockworks. Many parts have a loose fit and rattle quite a bit without shims and sleeves. I wish more parts had machined finishing like the gearbox and rear arms do. That would increase the cost quite a bit, though.