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Hello Everyone

I have two 30 plus year old Kyosho RC cars one is an Optima that was a chain drive that has been swapped over to a belt drive, and a Ultima that has a graphite chassis with a front red aluminum nose piece that the front steering is screwed onto.
Yes I know they are old but both are in good shape! I found the trunk they were stored in for years after cleaning out the shop after the Beachi creek forest fire he in oregon. So i got to thinking about updating both of them???
so I started looking at new parts and going down to the rc track in salem oregon to see what could or can be done to the Ultima and what's online and found for the Ultima a new Aluminum chassis?? about a 100 bucks and swapping over to the new brushless motor systems
that are out now! But the people I talk to at that track just want to sell new car kits and at the hobby rc shops say they don't even stock any parts for these rc cars no more.
So how big of a problem would it be to do this Aluminum chassis and do i understand this right if going to a brushless motor a new trans would be needed? if so what would be needed for the trans??

The optima I was thinking of converting that into a rock crawler! ??? The gearing would need to be changed I think? to slow it down. I do have some big rims and tires for the monster truck conversion I played with over 30 years ago so they might still work? and then a brushless motor but then what about the tyranny on this with the belt drive??
I have looked here but mostly it is all about the newer versions of these cars!!

So has anyone done any mods like this to these older Optima and Ultima's???

Hi Merlin and welcome to the forums.

I believe you can safely run 17.5 or milder brushless motors and 2s with vintage plastic Ultima/Optima gears. Anything hotter and you'll want to consider buying a new re-release transmission from Kyosho as they come with metal gears throughout.

I think it's going to be difficult to gear an Optima low enough to make a good rock crawler - not impossible but definitely a challenge. As an option, perhaps you could consider fitting it with a truck body, a set of mud tires and make a trail truck instead - something that typically runs a little quicker than a crawler. I've seen some Optimas converted into trucks and the look very cool!

Anyway, post some pics if/when you can.

Howdy,
The Ultima and the Optima has been re-released so new parts are obtainable.
If You want to go brushless with Your Ultima, install a re-release transmission - The input shaft has a slipper.
The Optima is not the best base for a rockcrawler, but if You´re really keen on it, clean the diffs and fill them with epoxy glue.

Hello
Thank you for your advice!!

I am new to this web site so, I think with all things outdated this has been hashed over and over! But for me it is all new to a point! Thirty years ago these two rc cars were the kings on the indoor dirt tracks! everyone had them rc10's
Then the Ultima came along and cleaned every other car's clocks
like all good things I got Married and these cars got well stored the new wife said to sell them! " Your to old to be playing with kids stuff !! " are fist son got old enough so I gave them to him! Well he was not very kind to these cars and when he broke them
it was " I don't know what happened!! " so when I found out well i fixed them and back into storage! Two more sons came along and they were even worse on them!! Kids and the thing if they don't earn it it is ok to break it and mom and dad will get me new stuff!!

So now they are mine again and i am working on the Ultima! I would like a new rock crawler a Axial rock crawler but 600 bucks???? I like My Fly fishing and Fly tying way better then a 600 buck-a-ro rock crawler!
So like I said i do not mind I am at 60 years young taking my time one car at a time and doing the modern conversion on both but the Ultima first, so i got new servo saver installed and over 140 buck in new steering parts, linkages front and real bulkheads then i seen these aluminum cassis for the utlima a rt6 aluminum main chassis??? I found some info here and they are 13mm longer then stock?? is that right? would this be better then this old graphite ultima pro chassis I got??
As for the RE RE transcan that be gotten at Kyosho America web site?? I looked but did not find any trans as a re re trans there. Sorry I to am old and out of date on this stuff, back then all this new and cool stuff was just hanging on the wall at the track and it all was SAYING BY ME I NEED TO BE INSTALLED ON YOUR CAR!!!! I WILL MAKE YOU SO MUCH FASTER!!! Well sorry I got carried away there I though i was back 30 years ago
My Utima is running again but I see all this new old stuff out there and well that itch to tweak is back i got a new ESC for it from the salem track and after one battery run reverse does not work well my fault i think it was only like twenty buck i just did not want to pay 180.00 for a esc.
is there a parts list or a part number for this re re trans?? somewhere i can look it up at?? Thank got for having you own computer so you can hide what you buy from your wife Ya well I am old enough I don't care how loud my wife BARKS now besides she is getting new carpet but I got to pay for it !! so she can bark all she wants to!!!! I burned the dog house down!!!

Uthima
New better ESC ! what i find on the web say rock crawler ESC !
Brushless motor ! though this La mans motor is really fast
this re re trans ! parts list were to find?
would I need longer or shorter Dog Bones??
is that aluminum chassis heavier then this pro graphite Chassis or is it better then the graphite ? does it use the same body as the ultima pro??


Again thanks for letting me into this forum group and THANK YOU FOR YOUR HELP!!


Bill

Thanks for the story, Bill.
But we still need pictures though!
Regarding the RT Ultima chassis - it´s a no go. This is a modern truck chassis and won´t fit Your vintage Ultima.
A graphite chassis is a nice option, both then and now. So if You don´t plan on racing beserk hitting every curb with Your Ultima, I´d keep that chassis.
I´m not updated on the prices of the re-release Ultima, but if they´re discounted to somewhere near 200 USD, I´d buy one for Your purpose.
Build the re-release, practise driving, and then if You feel like it, harvest the gearbox and mount it on Your Vintage Ultima.

If You´re not emotionally attached to Your Optima, swap it for a used Axial trail truck of some kind.

Thanks for the help

i would like to at least build this re release trans ! I have been looking Kyosho America web site and other web sites for a list of parts to build this tranny
there is a posting here
https://www.rc10talk.com/viewtopic.php?t=42881
and
https://www.rc10talk.com/viewtopic.php?f=30&t=45632

but I am racking my poor old brain trying to find the parts! It looks like the tranny case on my ultima so is it just internal parts needed?? to build this re release tranny??

If You want to go brushless with Your Ultima, install a re-release transmission - The input shaft has a slipper.

I believe you can safely run 17.5 or milder brushless motors and 2s with vintage plastic Ultima/Optima gears. Anything hotter and you'll want to consider buying a new re-release transmission from Kyosho as they come with metal gears throughout.
this i have looked for at Kyosho even typed in re-release transmission in the search bar

or am i to old to think of the new terms or names for the parts?

Bill

Here´s a parts list : http://www.kyosho.com/jpn/support/instructionmanual/buggy/pdf/30625-ULTIMA_spop.pdf
You´ll ned the new transmission housing to go with the internals. Different bearing sizes.

I'm sure you'd be able to restore those with parts off eBay sellers or similar sources. They are collectors items for many who would keep em on a shelf and be happy to buy them off you in any condition. I run a gv beagle Optima clone but only on a buggy special motor, cheap ESC and NiMH battery. Good enough unless you want to win races. Biggest setback for racing is the cost of a transponder but I'm not into that.
You could sell your house and its contents to pay for this hobby but I'm into budget solutions. 180bucks for an ESC!! must be encrusted with diamonds, mine cost about 12bucks and hasn't burnt out yet.
Happy rebuilding to ya.

If you source a kyosho option house torque limiting clutch on ebay, u can use your old tranny with big brushless power.

TheDiamondOne wrote: ↑Tue Jan 05, 2021 8:50 am If you source a kyosho option house torque limiting clutch on ebay, u can use your old tranny with big brushless power.

Actually, the word on those were that they worked like crap and didn't last long before the gear got chewed up. I don't think you'll find a single positive review of those clutch bells.

https://www.tamiyaclub.com/forum/index.php?/topic/44066-torque-limiting-clutch/

The only way I'd recommend using anything up to 10T or so brushless motor is with a belt drive conversion and OT-74 limiter gear set (for the Optima), hard final pinion gear in the rear diff and a modern ESC that you can dial down the punch so that the car doesn't have too much torque on acceleration. The punch adjustment functions more or less like a slipper gear. Note that the limiter gear isn't a slipper gear, it just has a beefy spring or a set of spring washers (there are 2 variants) that protect the counter gear from damage while landing jumps. I did all those upgrades with my Barney Optima build and went with an 11T Tacon 3200 kV motor, I wouldn't recommend going any more powerful than that with a vintage Optima or Ultima...and far less than that if you don't do some serious bulletproofing.

https://www.rc10talk.com/viewtopic.php?f=30&t=21530&start=172

Thanks Everyone

From looking at the parts list from the 30625-ULTIMA_IM manual the tranny case is the same as my stock case a UT002 so from what i am looking at the slipper clutch is all internal parts conversion is this right??
Then looking at the Differential gears I have not looked at them for thirty years now but I think they are made from cheap Aluminum and think back to the days back then we had to always replace these gears as they did not last very long on the Dirt tracks !!
So do they make Steel Differential Gears today ????
i do not or will not race the Ultima or my Optima just to go out and play a little bit the motors I have are brushed motors and are old but still work they have all been rebuilt many times! From what i have read between brushed and brushless the brushless motors
last longer! but the guy's at the track said if I went to a brushless motor it would eat up the gear box so I would have to hunt down old parts to rebuild or spend $180 for a programable ESC with a program box??? that would
eliminate having to constantly rebuild a gear box???
They said it would be cheaper to buy new cars at this point!
For me I look at what I have in the Ultima and Optima and see how and what the kits had, compared to the all Plastic cars and truck that are maid today!!!

You don't need to spend that much. Here's a complete brushless motor, ESC and controller card combo that's similar to the set I used with my OptiMutt build (that's an Optima Mid converted to a mid-motored RWD car). I used the 12T version for that as it's also really beefed up. This would be a milder 13T package, the whole thing sells for $63 USD:

https://www.ebay.ca/itm/SkyRC-Leopard-1-10-Brushless-Motor-ESC-Combo-Program-Card-60A-V2-3000KV-13T-USA/181816072961

I found this Leopard Toro combo was very smooth-running. You can adjust a lot of performance variables with the controller card, including how hard the car accelerates (punch). The brushless motors are practically maintenance-free compared to the fuss & muss with brushed motors. You'll need a LiPo battery pack mind you, you can still buy some with the same rounded shape as the original NiCad/NiMH batteries, but they'll have a much longer run-time, and will maintain their full power throughout the charge cycle instead of growing weaker and weaker as the pack drains. You'll also need a LiPo battery charger to safely charge your batteries, because overcharging and over-discharging LiPos will result in explosions or dangerous fires. But, I think you could get all of those electronics for well under your $180 mentioned price.

Battery:

https://hobbyking.com/en_us/nano-tech-4200mah-2s-25c-hardcase.html

IMax B6AC Charger, a decent overall charger for most battery types:

https://www.ebay.ca/itm/Imax-B6AC-80W-6s-Lipo-Nimh-LIFE-Balance-Charger-RC-Battery-DRONE-PRIORITY-SALE/233638178926

The Optima & Ultima gearboxes were actually pretty decent, the weak link being the final pinion gear inside the gearbox. Once those were upgraded to hardened steel or hardened aluminum gears, the cars should be able to handle a combo like the one I linked. Hobby store employees who say modern power will destroy our vintage cars think we're all gonna do stupid crap like installing 6T motors with 3S LiPo batteries and stuff...but keep it sane, adjust the punch and you'll have a very quick, driveable car.

Ok Thanks

Due diligence?? Been reading and web hunting then all of your guy's advice
back in the day? I think no one ever talked about motor winding?? 5T too 25T??
So in todays lingo a 10T motor is way faster then lets say a 17T motor?
This kv motor thing is kind of stumping me!! I like good old USA RPM"s you know like the 427 Chevy Rat Motors

I was looking at Castle motor and esc
https://www.rpphobby.com/product_p/hwi38020421.htm

https://www.rpphobby.com/product_p/cse010-0164-01.htm

with this castle setup you can download the programing software to your PC and program the ESC from your computer! this seems easy??

then Hobbywing

https://www.hobbytown.com/hobbywing-xr10-justock-sensored-brushless-esc-sd-g2.1-motor-combo-13.5t-hwa38020240/p784983

https://www.hobbytown.com/castle-creations-sidewinder-3-wp-1-10-esc-motor-combo-5700kv-cse010-0115-06/p618577

https://www.hobbytown.com/castle-creations-sidewinder-3-wp-1-10-esc-motor-combo-5700kv-cse010-0115-06/p618577


So for the Ultima setup would you go to a sensored esc and motor or a sensorless esc and motor

then sense this is new school stuff what turn motor 13T to what 20T ??? then there is this KV Thing 3000kv or 4000kv or 6000kv ?? there is so many different setup's out there now it is like a kid in a CANDY store that has sticky fingers and trying to say i got nothing in my mouth while trying to mumble the words with a full mouth

I got a ESC from the race track and spent I think 29 bucks for it, then I ordered a 540 with an ESC off Amazon a Jublee ?? for like 50 buck and the ESC is the exact same one I got from the track but with different brand stickers on it but the stamping on the
bottom of both are stamped the same!!! ?????

i do not mind buying off of Ebay but i would like to get a quality Motor and ESC

i learned that cheap is not a good way to go now that most everything is made in China

I think I will just rebuild my Tranny and look for steel gears

Can some pro here download and install this Castle software it has a demo mode and look at it to see if it is any good?? or if it is worth buying a castle ESC and Motor sensored ?????

link https://home.castlecreations.com/download-castle-link


Bill

Bill - I know it´s a lot to take in for an old man But I told You that You´ll need the new transmission housing for the use of the new 2019 steel internals. That still stands.

Thank you

DennisM ok, can you clarify the parts needed, this is what I have come up with

Diff Inner Parts Set (OPTIMA 2 Part Number OT222
UT002 Gear Box (ULTIMA) Part Number UT002
UT008 Diff Gear Case & Pulley (ULTIMA) Part Number UT008
Gear Set (OPTIMA 2016) Part Number OT221
Diff Shaft (2pcs/OPTIMA 2016) Part Number OT224
Gear Shaft Set (OPTIMA 2016) Part Number OT225.
UT009S Motor Plate (ULTIMA) Part Number UT009S

The gear box UT002 is the same gear box that I currently have in my Ultima and i have a spare gear box I just found in the old parts box so from the list I got from here http://www.kyosho.com/jpn/support/instr ... A_spop.pdf
it is just the internal parts to build the re release trans right??? I am not trying to be a pain about this just clarification please

as for the OT-74 limiter gear set, that is the pinion gear with a built in clutch right?? I got three of those in my old parts box one is melted the other two are very lose!! thinking back to those days these things did not work that well either!!
Aluminum and plastic gears did not last very long no matter what you did back then.

Dennis I do not mind building a new trans i just would like to get all the parts needed in one order and not have to place to or three orders
For me this is more of a resto for both the ultima and optima but both a playable resto trying to digest all the new stuff
So I went Hobby town today and I got a Totally different story about these cars and that was not much can be done sense they are so old ?*&^$??? and all I asked for was what they had for a 540 brushless motor and a programable ESC

I have seen some very nice picture of old Kyosho cars on this forum and that is what I am aiming for with my cars!!! Maybe one day I will get a grandson that is not destructible as my sons were well still are, and I can pass these cars to him one day

I Really Truly appreciate all of YOUR Help and ADVICE!!!!!

Bill