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Cliff Letts 1990 roar winning yz10

Posted: Mon Jan 22, 2018 3:04 am
by pedro
This could take awhile but one has to start somewhere :D
I can't believe how modified the 4wd cars were back then about the only stock part is the motor mount everything else is either modified or replaced the car you purchased in the shop was nothing like what was winning the races :roll:
Anyway here goes, so far I have made rear arms from delrin, nylon would have been my choice but you have to take what you can buy on ebay :)
Front and rear graphite shock towers made from a Kyosho triumph chassis (correct thickness) front tower looked like a modified 89 worlds tower so that's what I did.
Parts made to fit are
The rear rc10 hubs drilled to take the yokomo bearings.
Rear bulkhead i have lowered the hinge pin about 1mm as Cliif did. (this was a pain but done now)
Bulkheads have been drilled and tapped to take 4-40 screws in the inside corner this is because they used to break the outer corners off on big rollovers and crashes.
Slightly modified the layshaft just by removing about 5mm from each end less weight?
Front arms are rear arms that have had the outer hinge pin redrilled 5mm in from the old hole and the shock hole relocated 5mm in also and some material removed for the shock to clear.

Now the things to do

Remake chassis so cells are closer to centre.
Modify top deck as Cliff has, bulkhead caps also.
Shock shocks shocks not even close to that yet???

And the rest :roll:

Re: Cliff Letts 1990 roar winning yz10

Posted: Mon Jan 22, 2018 3:11 am
by pedro
A bit of a mock up to see how things are going.
I couldn't believe I had all the correct electrics but I did including a new Reedy gold star (not pictured)

Re: Cliff Letts 1990 roar winning yz10

Posted: Mon Jan 22, 2018 3:27 am
by Lonestar
That's pretty awesome!

What I never understood with all these "so far from production it's unreal" cars is, whether they came to all these "out-of-the-box" solutions via calculus, engineering and modeling (whatever was available in this era...) or whether this was like "let's try and see if it works, I'm a pro so I have enough time to try drilling any part I want anyway"...

Gonna be a nice replica - congrats on the arms! :shock:

Re: Cliff Letts 1990 roar winning yz10

Posted: Fri Feb 09, 2018 2:49 pm
by Dadio
Lonestar wrote: Mon Jan 22, 2018 3:27 am That's pretty awesome!

What I never understood with all these "so far from production it's unreal" cars is, whether they came to all these "out-of-the-box" solutions via calculus, engineering and modeling (whatever was available in this era...) or whether this was like "let's try and see if it works, I'm a pro so I have enough time to try drilling any part I want anyway"...

Gonna be a nice replica - congrats on the arms! :shock:
DIY was the norm for most of us , there was no internet , magazines had some articles on mods and adverts for some custom parts but it was mail order for most of us so DIY was really common .
Loving the build ive used a fair bit of delrin (acetal) on my 834b , probably more durable that nylon as well.

Re: Cliff Letts 1990 roar winning yz10

Posted: Fri Feb 09, 2018 3:44 pm
by uniquenamehere
Wow, I loved that car when I was a kid. You're off to a great start... looking forward to seeing how this turns out! :)

Re: Cliff Letts 1990 roar winning yz10

Posted: Fri Feb 09, 2018 6:08 pm
by scr8p
Nice servo! I gotta find one of those myself.

Re: Cliff Letts 1990 roar winning yz10

Posted: Fri Feb 09, 2018 7:35 pm
by pedro
Small update although possibly way too time consuming :? modified the front/rear arms and fitted the kyosho carriers (ot55) and srs steering arms also machined the alloy wheel hubs down in thickness these were the standard wide front end hubs. Bent up a sway bar and added the solder blobs each side to keep it centered. Also trimmed the Jammin top deck and bulkhead caps I am guessing this was a weight thing?

Re: Cliff Letts 1990 roar winning yz10

Posted: Fri Feb 16, 2018 8:34 pm
by Ronbo
How did you come up with the pattern for the rear hub carrier extension? Since it looks similar to Masamis 89 setup using the RC10 rear carriers. I would like to try the same setup. Also, OT55 hub carriers, is that Optima, mid or? I see several options on ebay, so just making sure.

Re: Cliff Letts 1990 roar winning yz10

Posted: Sat Feb 17, 2018 8:35 am
by pedro
Ronbo wrote: Fri Feb 16, 2018 8:34 pm How did you come up with the pattern for the rear hub carrier extension? Since it looks similar to Masamis 89 setup using the RC10 rear carriers. I would like to try the same setup. Also, OT55 hub carriers, is that Optima, mid or? I see several options on ebay, so just making sure.
The pattern for just about everything is a complete quess so nothing will be identical, yes i believe OT55 is from the optima they add more caster.

Re: Cliff Letts 1990 roar winning yz10

Posted: Sat Feb 17, 2018 12:06 pm
by Jirka
Ronbo wrote: Fri Feb 16, 2018 8:34 pm How did you come up with the pattern for the rear hub carrier extension? Since it looks similar to Masamis 89 setup using the RC10 rear carriers. I would like to try the same setup. Also, OT55 hub carriers, is that Optima, mid or? I see several options on ebay, so just making sure.
On Optima(s), there were two caster blocks: standand and ones with more caster than the standard if I remember correctly. You can verify this from Optima manual past list. And I also somehow beleave that casters standard blocks are the same on all Optimas including Mids.

You are creating a really nice replica with many challenging details e.g. how did You find out that rear buckhead needed some lowering? Really like to see this build ready and all those little and big tweaks that this car has.

Jirka

Re: Cliff Letts 1990 roar winning yz10

Posted: Sat Feb 17, 2018 8:58 pm
by pedro
Hi
If you click on the magazine pic with the rear bulkhead in it a few times in the bottom right corner of the article it says the rear pin was lowered for more ground clearance.

Jirka wrote: Sat Feb 17, 2018 12:06 pm
Ronbo wrote: Fri Feb 16, 2018 8:34 pm How did you come up with the pattern for the rear hub carrier extension? Since it looks similar to Masamis 89 setup using the RC10 rear carriers. I would like to try the same setup. Also, OT55 hub carriers, is that Optima, mid or? I see several options on ebay, so just making sure.
On Optima(s), there were two caster blocks: standand and ones with more caster than the standard if I remember correctly. You can verify this from Optima manual past list. And I also somehow beleave that casters standard blocks are the same on all Optimas including Mids.

You are creating a really nice replica with many challenging details e.g. how did You find out that rear buckhead needed some lowering? Really like to see this build ready and all those little and big tweaks that this car has.

Jirka

Re: Cliff Letts 1990 roar winning yz10

Posted: Thu Feb 22, 2018 3:34 am
by littleVETTE
damn peter. another lovely project to add to that stable of beauties. great stuff!

Re: Cliff Letts 1990 roar winning yz10

Posted: Thu Mar 01, 2018 3:38 am
by pedro
A bit of an update

Made a new chassis to look closer to the original and added some electrics, getting there slowly :)

Also just asking there is a sticker on the roof of Cliffs car that reads "Power under pressure" does this mean anything to anyone as far as where I can find it or where it may come from?

Thanks

Peter

Re: Cliff Letts 1990 roar winning yz10

Posted: Tue Mar 06, 2018 3:25 am
by isobarik
Looks awsome

Mv h iso

Re: Cliff Letts 1990 roar winning yz10

Posted: Thu Aug 23, 2018 6:14 am
by Bormac
Fantastic build