Project: Kyosho Optima

UPDATE ALERT! If you only want to read the updated article, please scroll down. Thanks!

One of my early racing buggies was the Kyosho Turbo Optima. I bought a used Optima from a friend and updated this car with the belt drive conversion and front one-way as differential, what worked excellent on the slippery dirt tracks we had at that time. At that time I just started my education as precision mechanic and I decided to make a new chassis with a lower plate to use saddle pack batteries. There was several reasons to do it. The lower center of gravity and the more forward position of the battery packs helped a lot to improve handling. The Optima was more ballanced and faster in the corners. And at this time everybody started to use single resistors for each battery cell for discharging the good old Sanyo NiCd cells. So with a saddle pack configuration it was much easier to install the resistors with crocodile clamps. The outline of the new lower chassis plate has the same, as the Pro Optima body I used and it was good to keep the dirt outside of the car.

Because the lack of money I raced this Optima in a time, when the Optima Mid came out. But my Optima was so fast, that there never was a problem to drive against more modern buggies into many A-finals. On some very bumpy racks, there was indeed a little advantage against the mid ship cars. The rear motor settled the whole car through the bumps. And some will remember, those bumps was huge back in time!

As the re-release Optima came out some years ago, it was clear to go back to the roots and build another Optima with some old ideas and some new ones.

The main idea was, to increase the wheelbase and to improve the weight distribution. Apart of the new battery holder to use low profile shorty lipo batteries, most things was exactly the same stuff I did more than 30 years ago.

So I started the project as always. Taking dimensions from the original parts, making an assenbly group and then modify parts. From the first look, it is the same layout that I used many years ago. I removed the radio plate and all the stuff around. Some modifications on the side plates and a new lower chassis plate.

The decided to increase the wheelbase by 21mm. Sounds like a huge step. But the standard wheelbase was always a little bit on the short side. I made clamps for the battery, inspired by the old Schumacher stick battery clamps, what I really liked. The battery is mounted pretty forward as counterweight of the rear motor. I knew, with this lightweight lipo battery, the Optima will go too light anyway. So I made the new chassis rails from brass meterial to get some more weight on the elegant way. The fit the longer wheelbase I had to print new tunnels for the belt.

The rear view of the CAD assembly. I made some little adjustments on the shock towers as well. I optimized the shock positions and also the positions for the inner suspension linkages.

I made all plates from carbon fibre, apart of the motor plate. So this works well es heat sink.

The Optima Pro body was always my favorite! Okay, I installed it a little lower.

No front bumper there. The little nose is the modified kit gear guard plate. You also can notice the new position of the outer ball stud of the upper suspension linkage. It is mounted directly above the king pin bushings. The original geometry has always too short upper links, what resulted too much camber gain. On this way now, the camber gain is much better with the longer upper linkage.

The overall look is pretty much the same as from my old Optima.

Chassis without body. I use JConcepts 2WD rims. Front and rear. The total width is 240mm now, what is okay for me. Schumacher 2WD Staggered tires at the front and Dart on the rear. Some may say it looks strange, but I like the look and the handling with those wheels.

Front View. The shocks are not original Kyosho Option House shocks. That are 100% copies, what you can order from a HK company named "Mayonnaise-RC" - no jokes! The quality is pretty good. I also ordered there the CVD Driveshafts and they are great! You find more informations on their Facebook Page. I use Team Associated RC10 shock spring clamps. I did this 30 years ago - why not today. I like a little mix.

The sleek chassis. Yokomo wing mounts. RC10 Worlds Car wing with large end plates.

For this project I use a LRP Phaser FM reciever, a LRP IPC Speedo and a Highest Low Profile Servo.

Yes, it is still an Optima! Really!

There is a Reedy Titanium 13x3 in the rear. Too much power? Yes, but it makes fun!

What I really like from the re-release Optima kit are the adjustable rear hubs to change toe-in. Today we know, why it was so difficult to drive on slippery tracks, with zero toe-in. One of the biggest differences between the manufacturers 30 years ago was the know-how of designing a good suspension geometry. Maybe the Kyosho cars was overall well designed. Has great quality and durability and attention to the details. But they simply did not understand how to make a good geometry. Yokomo, Schumacher and Team Associated was lightyears ahead with proper geometry, like anti-dive, toe-in settings, or caster/camber settings. And I am sure, this was the reason, why Kyosho lost so many titles.

As always, I use the great and timeless Lunsford turnbuckles. I hope, you can´t see the Xray pivot balls and ball ends, what I use in all of my Kyosho vintage projects at the moment. But they are so much better, than anything else today. And the look fit a Kyoshe very well.

How does it drive?

First of all: The re-release Optima is loud! Because the use of a complete metal gear drivetrain, instead of plastic gears from the past, the Optima makes siginficantly noises. I tested the Optima on an un-loved EOS carpet track near Hamburg/Germany. Super high grip. Again, Vintage cars belongs on dirt! But there was no other chance to test that beast. And what can I tell? It ran crazy good! The handling is neutral and the boost of the Reedy 13x3 brushed motor was crazy! I managed to make some crashes, but we talk about a Kyosho! It´s very robust. So no breaks. Nothing. Some weeks later there was the VOREM2017 Vintage race in Langenfeld/Germany. And I started in 5 different classes. A little advise from first hand: never start 5 classes in only 1 race! It was pure stress. In the practice runs my Optima rocked the bumpy Langenfeld track super smooth and predictable. On the jumps you instantly got remembered, that this is a rear motor car! Thanks god, we had no jumps back in time! But the overall performance was amazing! Unfortunatelly i was totally overcharged to handle 5 classes. It was a literally jump & run game. So I decided to run only 3 classes for the finals and my Optima had to stay at the pit.

But the old feelings came back with this car. The way it drives and the look and the familiar wrenching on the car - like an old friend you missed so much time.

As addition - I found some old RC Car magazines from 1989 with some of my race results.

My personal RC god and inspirator was a young man from Kiel/Germany with the name Lars Eytz. His Turbo Optima on the picture changed my mind. So my project is a little tribute to his style and perfection. Thanks, Lars!

UPDATE 2023

Hello again! We have the year 2023 now. The world is still turning and many things changed since 2018 - also my beloved Kyosho Optima!

After realizing, that brushed motors for vintage racing are cool, but way too much stress for the driver, when you try to run several classes on one event. It is not a power issue ans it´s not a heat issue these days. But you always have to keep an eye for your motor after each run. Checking the brushes and brush springs, if they run smooth. Checking, if there is dirt in your motor, checking the condition of brushes. It was and it is a big part of racing to keep your motor under best conditions over the weekend! Back in the days it was no big deal to dissamble the whole motor between the heats, but today I am old and maybe my focus is not 100% to win a race - to meet friends and have a chat with other racers seems more important today for me.

To make it short, I changed all my brushed vintage cars to brushless powered cars. And the fact, that most European races demand 13.5T for 3WD´s and 10.5T for 4WD´s, it is pretty simple to follow this rules for the near future.

But before we dive under the Optima Pro-hood, here are some nice pictures for you.

There were some changes at the front since 2018.

Nearly 5 years old and still looks fresh!

Front view - the mighty long shock setup. Exactly the same shock geometry as my Optima Mid.

The overall performance increased dramatical.

Because the original short front shocks delivered not much up and down travel, I changed them to the original Kyosho re-release Optima long shocks. As I mentioned before, these shock are very very good! I really love them!

With this new geometry - the right springs and shock oil - the performance is so much better!

Right side. I removed all analog technology. A Futaba reciever was installed.

Left side. As on all my vintage cars I took a LRP Flow-X Speedo. You don´t need a programming card, or an app to make the setup! Who knows, if you get your app in 25 years? So blinking and peeps are okay for me!

A Reedy 10.5T in the rear!

The front shows the Kyosho option CNC C-hubs from aluminium and Xray T4 2020 Touring Car aluminium front hubs. To reduce play at the king pin bushings, I use Yeah Racing bushings made from brass. They have a little more outer diameter to reduce play and works perfect! The whole front suspension has lee play now and the car is much more precise to drive.

I also use the Kyosho aluminium rear hubs and Kyosho universals all around with Xray wheel adapters, what you can get with different offsets.

Some more tuning at the front. Yeah Racing shock tower holders from aluminium and also the bell crank arms. The quality is good and the parts are pretty precise.

I added some weight at the front. The Optima need alot of weight at the front for modern tracks!

I made a front hinge pin plate from brass to gain a bit more weight here.

I also use the Optima Mid suspension arms in the hard plastic version. They are a bit longer for some reasons. If you want to make the same, keep an eye to your driveshafts at the diff outdrive. Maybe you need to shim that out. I use for all my Kyosho vintage cars Xray 5x7x1mm aluminium shims.

The Optima without wheels.

I have spent so much time into the shock setup!

Generally it is the most important thing in vintage racing to find the right springs, shock oils and pistons. Try to get as many springs as possible. I use Element RC springs on this cars, what are made for crawlers. But on some of my cars they work perfect!

If you are asking for a gear ratio with a 10.5T motor, you can take the biggest possible motor pinion. I run a 28T motor pinion without any problem.

The Optima Mid and the Optima - 2 brothers!

And yes, I had the chance to drive this one and some other of my cars in 2022!

Meeting old friends to drive old rc cars after more, than 10 years and racing our old buggies was great! We found an RC Car track outside from Hamburg, where we could drive for some days in last summer.

I know this guys since I was 14 years old. And nothing has changed us. Ha!

The German 4WD Buggy National Champion 1999 with his original winning Yokomo SPORT. Awesome! And we raced agaist each other after so many years. This was a great experience.

What happend to us over the last 20 years? Get married, get some kids? Build a house and making a career. Destroy the carreer and start someting new. Or fail again? Stand up and start something new? See your kids growing too fast. Still fighting to everything? Loosing your hair and get a big belly - start making sports to lose you belly. Failing with sports. Stand up and try again with all? If you turning your 50´s, the life seems to be much more complicated than ever before. Or is it just me?

Meeting old friend and racers helps so much! Same problems and same old jokes. That is enough to feel young and better at least for the little moment, when you meet them on the track.