Kyosho Torpedo Optima WC’87 – part 3

Welcome to part 3 of my Torpedo Optima build. You can find part 1 here, and part 2 here.

Yasunobu Hosoda designed and made the carbon front side plates for the original Torpedo Optima. (Image stolen from

I have received the carbon parts from Fibre-Lyte, and they look superb. Well, they’re not really carbon, as they didn’t have any good finish carbon ready that was thin enough, so I had them cut the plates in CSC, that is a mix of carbon and fiberglass. It has a fiberglass core, surrounded by carbon. I still believe the top plate is a couple of fractions of a millimeter too thick, so I might order another, thinner, carbon plate at a later time. The parts fitted right on the chassis with just a small modification to the top plate. I had to dremel off a millimeter on each side where it meets the chain guard at the front. It did actually fit without that small modification, but it pushed the chain guard too far forward, so the two 2mm screw holes in the guard that secures it to the top plate at the rear were misaligned by a millimeter or so compared to the top plate. If I order a thinner plate, I will fix that in the CAD drawing. The side plates were a perfect fit, and gave just enough clearance for the steering rods to move freely. I was a bit worried about those plates, as they have fixed holes for mounting to the chassis rails, and are not adjustable like the original Optima side plates. But it seems like I nailed the placement of those holes perfectly, and the tension of the belt seems to be spot on! A fun fact about the original Torpedo Optima is that the front side plates were actually made by Yasunobu Hosoda, now a famous designer for Yokomo! Atsuhiro san designed and made the top plate himself.

As always, the Fibre-Lyte parts came nicely packaged in bags. It’s very cool to receive the parts you have drawn yourself in such style!

I also got the OTW111 hard main chassis rails for the Optima 2016, as I couldn’t find a set of the original Option House rails anywhere. They look very much the same as the originals, but have more of a golden colour to them. They also have extra screw holes for mounting the top plate support. On this build I have two of those supports, and none of them are mounted in the same place as on the Optima 2016, so those holes are not used. On the original Optima they were secured by zip ties, but on the Torpedo Optima, they were only clipped on to the lower chain guard and screwed to the top plate.

Optima 2016 OTW111 option rails.

I have fitted the top and side plates to my build, and as you can see, I have also mounted the “torpedos”. I got a bundle of old yellowed zip-ties in a Kyosho Ultima lot I bought a couple of years ago. I was going to throw them in the bin, but I’m happy I didn’t, as they look very good on a vintage build like this. I have also put on some of the decals I had Nathaneal Ellis of MCI-Racing print for me. Like all the custom parts on this build, I have drawn those decals myself, too. The screws are just placeholders, as I don’t want to mount the aluminum screws until the last minute, as they wear so easily.

“Carbon” plates fitted, together with the torpedo batteries.

The main parts of the build are done now. I still need to mount the rear sway bar, but that will have to wait until I get the aluminum rear shock tower from Derrick. He promised me to cut them this week…. I’m still waiting for the body from Raul and Garcia Graphix, but he has promised me to start on the paintwork, very soon. Daniel will send me the Sanwa Champ ESC as soon as he gets back to the UK from Oman.

The Sanwa Machine-1 that I got from Franky. It’s one of the best radios from that era, and the radio of choice for many top racers.

I have a Sanwa Machine-1 transmitter and receiver on the way from Franky Yeung. The model number of the receiver does not match the model that Atsuhiro san used in 1987, but I believe they had different model numbers relating to what frequency band they were, and if they are FM or AM. The set I will use is the 27MHz FM version, that is legal here in Norway.

My receiver is a SRC-2305RZ, while the one used by Atsuhiro san was a SRD-2305RS. I believe the only differences are frequency band and modulation type.

The Sanwa Machine-1 is the same radio as the Airtronics CS2P. I have had a few of the Airtronics branded radios offered to me, and I would like to thank all of those who helped me finding one of these cool radio systems. I still don’t have any leads on the Sanwa Contest HC servo, so if anyone have one of those, and could be willing to help me getting this build as authentic as possible, don’t hesitate to contact me.

Well, to finish off this third part, here are a few pictures of the rolling chassis. There will be a part 4, as soon as I get the remaining parts. If you scroll down past all the pictures of my Torpedo Optima, I have a little “surprise” for all you Optima-heads out there…..

The Torpedo Optima was not the first, nor the last customised 4WD Kyosho Atsuhiro san built and raced. In 1986, the year before the Torpedo Optima, he experimented with, and raced,  a very cool chain driven mid motor Optima. The car features lots of custom made aluminum parts, and it’s very tempting to try building one of those when I’ve finished the Torpedo….

Atsuhiro Ohno’s 1986 mid motor Optima.

And a few years later, around 1990 he also experimented with a electric converted Kyosho GP-10, with shaft drive. Notice the Air Supply Trix Thinka Modified motor……

Atsuhiro Ohno’s 1990(ish) electric converted GP10.

This is not a web-shop

This is not a web-shop, and beside what’s listed under the “FOR SALE” tab in the menu, nothing presented here is for sale, so please don’t ask. If I have anything I would like to sell, I’ll post it in the “FOR SALE” section.

About TomEG 56 Articles
I have been into RC cars since the beginning of the 80's, but have really never been much of a racer. I competed in some local races and some "Tamiya Cups", and actually came 6th in the Tamiya Cup Norwegian Nationals in 1987. My main interest has always been building and modifying, and that's where I still am today. Through the years I have been able to build a solid network of contacts around the world, consisting of both former and current members of the industry, as well as quite a few of the former top drivers. I have a genuine interest for the history of the 1/10 scale off-road buggies from the 80's.


  1. I am impressed that you find these prototyper and the history about these models, this is now my favorite Web hangout 🙂 thank you Tom.

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