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I have a parts Optima that I have been thinking of building into a runner.....I have searched and found random comments and know that not everything is interchangable, but what 2016 parts can be swapped out on the original.

I like the flush screws in the rear plates and would like to swap them out.

Also, the diffs internals are different correct? so if I want the slipper clutch, I just can't add it on, I have to swap out the entire diff.....correct?

I was able to fit the new slipper assembly and gear set into an Ultima housing after several hours of milling, drilling, fitting, inventing new cuss words, and making my own spacers and shims.

I’d say it’s...possible...to add these parts to an old Optima but I don’t know if the fuss would be worth it. I’d just buy a new Optima or Javelin and keep yours OG and cool.

I took the time to add these parts to my Ultima because to my knowledge, no one has done it yet and Kyosho hasn’t re released the Ultima.

The new trans cases are pretty cheap on eBay and all the gears and bearings you’d need would probably put you into the $50-75 range so you could probably convert yours over for around that price. Don’t quote me exact compatibility though.

I’m just getting my feet wet in Kyosho land... I’ve built one new Javelin and started working on this custom Ultima

That second post about just purchase the gear cases and gears is what is beating out all other choices right now.

I already have a Turbo Optima and a Turbo Optima Mid that are both OG, this extra one was a parts car and instead of buying a rere I thought I would make this one a bit of a mutt.

orangemazda wrote: ↑Thu Mar 08, 2018 8:05 pm I was able to fit the new slipper assembly and gear set into an Ultima housing after several hours of milling, drilling, fitting, inventing new cuss words, and making my own spacers and shims.
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You wouldn't feel like slapping one more of those together would you I have a Pro XRT (team version) that has the transmission no body likes and made drivers dump Kyosho for other rides, I found a reference somewhere here that mentions the the Ultima case does match up with the Pro XRT mounting. So if I could do that, I would be freaking thrilled.
I would really like to learn what you did so I can attempt to recreate one for the Pro XRT.
Even the Ultima box with some upgraded internals would be better I imagine.
My third choice is getting an A&L Lethal Weapon.......I have been told these are the bees knees (whoops, can I say that here )

To convert the Original Optima into 2016 gear/diff spec. will set you back 100-120 USD + 30-40 for the counter sunk plates.

Regarding the Pro Xrt, I´d go for either a Lethal Weapon, a Triumph or a RB transmission - None of those are plug and play, but the Triumph has the same bolt pattern as the SST. Parts availability on the Triumph transmission is not the best.

DennisM wrote: ↑Sat Mar 10, 2018 2:09 am To convert the Original Optima into 2016 gear/diff spec. will set you back 100-120 USD + 30-40 for the counter sunk plates.

Regarding the Pro Xrt, I´d go for either a Lethal Weapon, a Triumph or a RB transmission - None of those are plug and play, but the Triumph has the same bolt pattern as the SST. Parts availability on the Triumph transmission is not the best.

Decisions, Decisions.....For about double the price you mention I could get a nib rere. I did get the plates for about 7 dollars though.


For the Pro XRT (really need to start a thread of it's own), I found a post on here that mentions the Ultima gearbox bolt pattern is the same, I heard the Triumph one could be used....but parts would be a pain. Why would the Triumph be one you would choose? I've seen comments on other sites saying they were not very good.
There is someone selling a Lethal Weapon with power clutch on eBay for 130-ish dollars, but I have never used one and was not sure how it would work out and how easy it would be to get replacement parts for it.

I own Factory Works and Vintage Team A&L, probably my transmission you see on eBay. The Ultima diffs are wider than rc10, so to use the rc10 version you would need longer dogbones. We have one kyosho kit left that has the old wide diff. We hope to have a solution to the diffs for the kyosho and Tamiya rigs at some point but as far as the near future that is it.

Besides the differential, the inside and outside the trans is the same- minus the drill template and trans brace which are car specific. To mount on an Ultima there are two holes that are reused and two that have to be drilled. I do not know how that would work on a Triumph but I suspect it would be the same scenario (edit- I see the Triumph is mentioned so apparently it’s a fit. This was before my time owning the company haha) I’ll attach the mounting instructions so you can get a feel for it.

Ultima Triumph and pro-x all share the same bolt pattern regarding the transmission

So fitting an sst is no problem on the ultima

Med vänlig hälsning, iso

The OP has a Pro XRT and wants to replace the SST transmission with one a bit more serviceable and with parts availability.

Kaare-65 wrote: ↑Sun Mar 11, 2018 5:48 pm

DennisM wrote: ↑Sat Mar 10, 2018 2:09 am To convert the Original Optima into 2016 gear/diff spec. will set you back 100-120 USD + 30-40 for the counter sunk plates.

Regarding the Pro Xrt, I´d go for either a Lethal Weapon, a Triumph or a RB transmission - None of those are plug and play, but the Triumph has the same bolt pattern as the SST. Parts availability on the Triumph transmission is not the best.

Decisions, Decisions.....For about double the price you mention I could get a nib rere. I did get the plates for about 7 dollars though.


For the Pro XRT (really need to start a thread of it's own), I found a post on here that mentions the Ultima gearbox bolt pattern is the same, I heard the Triumph one could be used....but parts would be a pain. Why would the Triumph be one you would choose? I've seen comments on other sites saying they were not very good.
There is someone selling a Lethal Weapon with power clutch on eBay for 130-ish dollars, but I have never used one and was not sure how it would work out and how easy it would be to get replacement parts for it.

The price mentioned for the optima plates, was for a full set - It´s fully possible to counter sink the original plates too

The only reason I´d go for Triumph transmission was to avoid drilling the extra holes in the chassis. There´s is nothing wrong with the Triumph transmission - On the other hand, the Triumph as a hole, can be debated
If Jeff has spare diff- and layshaft pulleys for the Ultima LW, I don´t see any problem in going that route - Building a Triumph transmission is going to cost about the same as the LW, But spare pulleys are going to be 3-4 times as expensive