Kyosho Optima to Optima Pro Conversion

 Kyosho Optima to Optima Pro Conversion Build.


Hello once again all RC enthusiasts from around the world.
I hope you are all well.

As the title suggests, I am going to convert my never ever used shelf queen Optima (re-re) into an Optima Pro 4WD.  The conversion will require a substantial rebuild of my beloved Optima. As my Optima is fitted with the belt drive option, I need to replace that with the chain drive system with the parts supplied in the kit. This is key to the buggy being an actual pro reproduction. I could leave the belt system in place, but then technically it would not be a true Optima Pro. I am waiting for all the correct parts to be delivered before starting the rebuild process. I will also be using the (as close as I possibly can) box art colours. I know for a fact, I will not be able to find some parts, as they are very rare and if available very expensive. So with that in mind, it will be done (in the famous words of Frank Sinatra),
 "My way".

From this

To this

Or this.

Pictures courtesy of Google!

I have just ordered a reproduction body and under tray from Kamtec Models and it cost £32.19 including delivery. I do hope it is a better reproduction than my standard Optima. I do remember that body was not the best I have seen and I wish I had spent little extra to get an original Kyosho shell. However, in this case I have no option other than to buy a reproduction. Having said that, I have heard many excellent reports of other Kamtec body shells.

 This body shell can be found at Kamtec along with a superb range of some great classic bodies  and other amazing body part options! You will be gladly impressed with their selection.

As you can see the new Optima Pro body shell and undertray arrived today (11/4/22). I must say I am quite impressed with the quality, body details and the shapes I will soon be working upon. 

My only little problem is that there are no cut lines on either the body or under tray. I can however, see some faint drill points on the under tray of which I will check, and if proven correct, I can work from this known data point.  What I wasn't expecting, was a full set of window masks, which is a mega bonus!! Thank You Kamtec!

As I stated, there are no cut lines on the body shell and only vague markings on the undertray. With this in mind, I quickly took my Optima from it's storage area to use as a measuring reference. 

I first of all removed the excess material from the undertray using a cutting disk on the rotary tool to get close to the vague lines. I then, again using a cutting disk removed the excess material from the front and centre and then did a test fit.

In the above picture, I have removed the material at the front of the undertray and test fitting it. I can see this being a very time consuming operation, what with having to test fit each time I make an adjustment. However, I would rather spend the time and get it right the first time and that will require a lot of patience. I did notice whilst working with the undertray that the plastic is quite thick and very strong. 
The next operation will be to remove the material at the rear of the tray, of which I think will need a lot more effort and time to complete. I think I may have to remove the rear bottom arms in order to fully fit the tray.

After removing the rear lower arms, I could test fit the tray. There was obviously a lot more material to be removed judging by the bulges in different places. After doing a lot more research, I found there is and area at the front that needs removing, yet the cut lines are not visible in that area.

In the picture above, you can see the 2 bolts heads (2 on each side) are fouling the tray and causing it to bulge out and also preventing the tray from sitting flush. 

After removing the correct amount of excess plastic, the undertray now sits flush at the front. I need to remove a little more around the rear bolt, just to give a little more clearance. Now there is a gap, a big one. In hindsight, I should have removed the rear bolt and trimmed only to the bracket. I could have then drilled a hole in the tray and put the bolt back in, to secure it. However, it's too late now.

The undertray now sits on the body quite well however, there are still some places that require attention for better fitting. 

Although the undertray is quite a good fit, there are still many hours to be spent adjusting and sanding to complete. Just for a guide, I placed the shell onto the car in roughly the correct position and it looks like the driver figure will not fit under this body. However, I'll cross that bridge when I come to it.

After removing a lot more material from different places, the undertray now fits quite well. It is not 100% perfect and I never expected it to be so. This is what happens when using copy parts, but to be fair, I had no other choice as Kyosho discontinued making these parts decades ago. 

The above picture shows the front chassis bolts now cleared of fouling the undertray. I also had to clear the steering rods of fouling the tray. The front of the tray no longer bulges out. I may also add, these should be (and were) the first part shaped, because if the front fouls any part, the rear will never fit.

 As I have just stated, if the front of the tray is not fitted correctly (trimmed), the rear of the tray will never fit. In the picture above you will see I have replaced the rear lower arms after removing a lot more polycarbonate plastic to allow the arms to move up and down.

There are 2 pre threaded bolts holes on the chassis legs (for the Javelin kit I would presume), so I drilled 2 holes and secured it temporarily with 2 small bolts. I will need to replace the screws in the future as they are too long.

A rear view of the Optima, showing the undertray. As you can see, I still have many hours to spend sanding and smoothing the undertray.

After many hours of sanding with P800 grade wet and dry and a sanding block, it is starting to take shape. As you can see the chassis bolts are completely clear of the undertray and fit really well.

The rear of the undertray now fits just as well. The red arrows indicate the tray is in the correct position, just above the hex bolts.

A full underbody picture of the undertray that has been sanded and shaped to quite a high quality. My only regret, is the gap at the front. Again, in hindsight, I could have done better if I had better prepared for the job in hand. What I am pleased about is the overall fit of the undertray, which should mesh perfectly with the upper body shell.

I am so happy I put in the extra hours and effort to see it complete and fitting almost perfectly for a reproduction undertray. It really has paid dividends in the end result and I am well pleased. I only hope the upper body turns out as good.

I then removed the undertray and placed the body in place on the car and marked out where the suspension brackets are placed. This may seem an inaccurate way to do this, but I am simply using them as a guide. 

You may think removing the undertray a waste of time and effort, but there is a reason for this.

If you look closely to the picture above, you can see the undertray is actually inside the upper body. I then followed the lines of the inner undertray with masking tape.

I then used a light to shine through the whole thing, and this showed the outline of what was behind. I then carefully followed the line with a marker pen and allowance for the depth. Again, these shapes and dimensions are not yet set in stone.

After following the inner shape, I am left with this. Yes, it's not a pretty sight but it is accurate to the undertray.

I know my free hand drawing is rubbish but I will make up for that during the sanding and shaping. But first of all, I need to start cutting away the excess material. 


Whilst doing further research on the shaping of the upper shell, I noticed my cut line (at the rear), was completely wrong.

After a lot more marking and measuring, I was getting somewhere near the actual shape. However, I have left excess/extra material just in case I am wrong.

And a view of the (mirror image I hope) other side markings. Some people may say the marking's are too thick and I should have used a fine point marker. However, the thick line is very forgiving and I also use it as a tolerance to unsure I do not remove too much material (plastic). 

After removing as much material as I dare, I needed to check and remark the suspension towers dimensions on both sides, to ensure the body was square to the car's chassis. 

Another check of the measurements and markings.

And another check of the markings. And I quote from an old friend of mine (MM) "measure twice, cut once". In my case, I have to measure 5 times and make very small cuts!! It looks as though I am going to have to remove all 4 shock assemblies in order for a better measurement. It's better to be safe than being sorry.

After removing the shock assemblies, I could get a clearer picture of how accurate my measurements had been, and it wasn't bad. I had always intended to use the original Kyosho shocks from it's own kit anyway, but I will have to empty them of all oil, as they do have a tendency to leak. Anyways, my lines were accurate, from front to back and from side to side.  The body contours also line up nicely so it's time to cut the recesses for the shock towers.

After making the cuts, it was obvious I needed to remove the shock bolts as well (orange arrows). I wonder if that means the shocks need to be fitted with the bodyshell in place?? I am also now starting to think the driver may indeed fit inside the Pro bodyshell. We shall see.

After many, many hours of frustration this is my progress. Mistakes (many) have been made simply because I was rushing it. I also did not thoroughly prepare or research the subject, which was my fault. I have no one to blame other than myself. I might be able to hide some of the mistakes with decals and others may sand out (fingers crossed). 

If you look at the rear of the upper body shell, there is a cut mark from the rotary tool.  DOH. Hopefully I can either remove further material or shape it in somehow. The body shell itself is also splayed down the middle, hence the tape. I may try and heat it a bend it into shape. 

There are still many, many hours to be spent, once again sanding, shaping and head scratching to come. I removed the masking tape only to pull away the protective plastic layer.  DOH! This has not gone to plan at all. DOH!! Still, I must move on.

Many hours later. I still need to spend further hours to complete. As you can see I have reinstalled all the shock assemblies and the 4 wheels to get an idea of what it looks like. 

If you can remember, I made a mistake with the rotary tool and put a cut in that should not have been there. I had to remove the damage with another line further in (yellow arrow), yet copying the rounded shape. It my look ok at the moment as the body is clear, but that might change when the paint is applied. 

Another mistake I made was, (the rear yellow arrow) I removed too much material at the front. I should have left enough material to allow a hole to be drilled and the rear bolt going through it. DOH. The green arrow is pointing to masking tape which is shaping the upper bodyshell inwards as the body shell is splaying outwards. I will try and use some heat to help correct the shape.

As you can see, there is still a lot of shaping and sanding left to do.

Again after many hours of carefully sanding and shaping, this is my progress. I t doesn't look like I have done much, but believe me I have. There are still many hours of shaping, sanding and decisions to be had before even applying paint. I have to say, this is a stinker of a shell to cut, shape and sand. No wonder it's called a Pro, as you need to be one to complete the shell and undertray.

As you can see the trim lines are now a lot cleaner and this will aid with painting the shell (and undertray), as the excess burrs can wreak havoc during the painting process.

It is getting there slowly but surely. 

Too slowly for my like, but if that's what it will take then I have to finish them ready for paint!

Let us continue with the sanding and smoothing of those rough edges!

I know I always mention the "Many hours Later" description, as it is the truth. The concentration needed to complete even the smallest car is intense. As I have pointed above there are still small areas to tidy up. The part I have arrowed, could have the potential to hold excess paint and cause a run. With the time I already have invested in this project, that is a mistake I can at least avoid! However, I have seen pictures of the Pro in the Optima House that have been trimmed in a different manner all together. Reminiscent of the Optima Turbo body. I may yet decide to do that.

In the above picture, the yellow arrow is pointing to where the outer protective film has come away (upper body) from the shell. This does happen when using tape over the protective film. It is not a scratch in either the body shell or undertray as it looks in the pictures.

Although the body shell and undertray still need a little more tweaking, I also dug out the original shock assemblies to replace the aftermarket one's I have fitted at the moment. They are also a lot slimmer the the after market adjustable shocks and will fit perfectly. As I previously stated, I will drain them of oil before refitting. I also have a new set of wheels (2.2") and a choice of 2 new style of tyres to fit to the car. I also have the paint (box art) in hand to paint the shell and tray. However, I could change my mind!! DOH

After a lot of thought, I decided to go with the box art colour. This way mainly due to me already having the paint for this particular project. The paint I am using is Tamiya PS-19 Camel yellow and I quite like it.

I applied 3 coats of the Camel yellow ensuring I had an even layers using a bright light shining behind. The masking take is simply covering the holes the attach the tray to the chassis, ensuring the paint does not come through.

Now there is paint applied, the beautiful shapes and lines of the tray can be seen. 

The arrows in the picture above are indicating some deep crevices that is difficult to reach with the spray, but I did that area in more stages. 

As you can see I ran out of PS-1 Tamiya White paint so I need to order more to cover the sparse areas. Therefore I cannot remove the outer protective film yet nor the masking tape. DOH. 

With the upper body shell on top of the undertray. 

It's looking good if I must say. I can't wait to get the main colour on the upper body shell to show off the shapes and lines. I still have to order some reproduction decals, but I first need to find a supplier.

After making some small adjustments, I refitted the undertray. Again after some small modifications to the body shell, I also refitted it for a test fit.

Another picture of the tray and shell.

With my upper body fitting the undertray just about perfectly, I was happy to move on with painting the shell. 

After getting the room up to temperature (arrowed above) and masking up the vunerable areas, I started laying down the paint.

Again I will be using the Tamiya PS-19 Camel Yellow, which is a lot darker than the standard yellow. To try a keep the depth of the colour, I will be backing the paint with Tamiya PS-41, Bright silver, where I would normally use Tamiya PS-1, Bright White. 

A picture of the paints I am using.
PS-19 Camel Yellow is the main colour.
PS-41 Bright Silver is the backing colour.

After a very light dusting of the silver paint, I placed the bodyshell in front of my homemade UV light to cure. When I say "dusting", I meant I didn't do a full thick covering or layering.

After a short while in front of the UV, the paint was not totally cured and I find this the best time to remove protective film and masking's (except window masks). And it looks stunning IMHO.

As I said about the undertray, once the paint is on, the shapes become alive and I love it. The light coat of silver paint brings out the depth of the Camel Yellow. 

I have to say that the window mask at the front is not cut straight. DOH. I will have to see what I can do about that at a later date.

As you can see from the above picture, the silver paint is not completely covering the Camel Yellow. In fact, it actually looks gold and I'm really happy with it! I now need to remove the undertray and back it up with the silver paint!

Looking good for me. I will obviously let the paint cure over night so as not to scratch it when fitting it to the car.

And in the blink of an eye, the shell is ready to fit as can be seen in the above picture.

Not too bad at all, I think.

I do plan to add further paint to the outside of the shell and it is a matt black spray paint. I just need to work out where it needs to be positioned.

I have now fitted the new wheels and tyres. I have, for the moment chosen JCRacing 2.2" Pepper pot wheels finished in white. I chose these wheels as the are a very close match to the wheels used on the original Optima Pro. The 2.2" size gives me a much much wider choice of tyres than the originals. I have also chosen a narrow style wheels for the front however, I may changed them to the wider style wheel.

For tyres I have chosen the Schumacher Full Pin tyres. Again these are quite similar to the originals however, I would love a set of the original Pirelli tyres. These tyres however are no longer produced by Kyosho , but the good news is there are reproduction tyres coming to the market. How much for a full set of these tyres is another question. I would also love to paint the tyre writing on this set, but I think my steadiness isn't up to the job, but it would look super cool if I could.  

I have over the years of owning this Optima, I have made a couple of tasteful modifications. I replaced the plastic lower arms on the suspension to some brushed alloy lower arms and cost about £30 for a full set. I also replaced the original shocks with some adjustable and bigger bore shocks but in the correct colour. The shock set was about £20, but were only bought for display purposes. Also, the original Kyosho shocks seeped oil over a period of time, so I changed them for a set cheap Chinese cheap shocks with little to no oil in them.  I also have 4 sets of wheels for it and now 3 body shells.  

As I said, I have changed the front wheels to the wider type wheel, which to be fair is the correct width to use. I also think they look a lot more aggressive to behold. I also used the Schumacher full pin wide tyre on the front.

They would also provide better grip in, if I were ever (and highly unlikely to ever do so) to run it.

I love the look of the JCRacing wheels as they have an awesome semi deep dish like inner. These wheels were £10 for a set of 4 which I think is good value. The tyres worked out to be £30 for 4, which I think is quite expensive but they are genuine Schumacher tyres to be fair and they look the business. The wider tyre also have a lower wall profile than the narrow full spike, so that's a bonus in the looks department. 

I can't seem to find any correct decals for this car, so from this point I am going to complete it as best as I can with parts and decals I think will fit the cars theme.

For my first tasteful (I think at least) modification, I am going to highlight (actually darken) the window frames. I am going to use matt black paint and spraying from the outside, as I cannot now do it from the inside. First of all I had to mark out the area to be painted and seal off the rest of the body with masking tape and Tamiya tape as you can see above. I know this is not box art but it is in need of some detail. Time to head off to my little paint shop.

After a couple of coats of matt black, the window detailing looks quite good.

I have also changed the wheel nuts to anodised orange to go with the body. I do think they look cool an really show off the wheels a treat. I thought they maybe a bit tacky, but I do like them and they were only £3.95 delivered. 

Another angle showing off the new wheel nuts. 

As I stated, I cannot source the correct decals as I had wished. Therefore, I am having to use what I think will work and not look out of place. With that in mind, I am quite happy with the results so far.

I have been tempted in the last couple of days, to use some leftover decals from the original kit and the Kyosho Beetle. However, I have held my ground and not gave in to that impulse. Saying that, there are some good decals I may use as finishing touches and tribute to Kyosho. A good friend of mine over at reddit  (abailey2110), has told me to keep a look out, as they are, from time to time, available on Ebay. Thanks man!!

Whilst trying to source the correct decals, something unexpected came up. Namely the Kyosho Optima Mid release. I had heard rumours of a Mid-July 2022 release, which gave me enough time to save and do both projects. I have however, been updated with the release of the 26th May 2022. Therefore, I have to put a hold on the spending as I HAVE TO get a Mid. I will get the correct decals later in the year.

So in the meantime, I have used some standard Optima decals and I used only the black versions.

As you can see, I have been quite sparing and minimalist on the decals. Also, they will be removed later in the year when I replace them with the correct ones.

I think they look quite good considering.

At first I was unsure of the decals, but they are growing on me quite quickly.
The minimalist look is just enough to break up the main colour, in my humble opinion. 

As you can see above, I have changed the wheels to the black version of the JC Racing pepper pot wheel. I think they look cool especially with the gold wheel nuts. The Optima Pro requires full width tyres at the front, but I only have slim fit wheels for the front. I have tried to order the black versions, but all suppliers seem to be out of stock.

As soon as the front wide wheels are sourced, ordered, received and fitted I will update the post.

Unfortunately, that is it for the project at this current time. As I said, the Optima Mid release is only 7 days away and I need to save the money for that. However, I will be returning to the project later in near future.

I have decided to put my Optima back to it's original style as I miss it too much. Therefore if anyone is interested in the body shell, it is for sale at £35.00.

 I will see you in the next project!!
Kindest Wishes!!
 Take Care!



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