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Old School Turbo Optima
Posted: Fri Jan 11, 2013 7:12 pm
by GeneralZod
Re: Old School Turbo Optima
Posted: Fri Jan 11, 2013 11:04 pm
by keithrc
Nice Turbo Optima you have there, I'm almost finished putting one together from parts myself. You'll want the hardened final pinion gear part number OT-76 listed in the Turbo Optima manual in the optional parts list on page 26.
There's one listed now, be quick though.
http://www.ebay.com/itm/Kyosho-Vintage-OT-76-Hard-Final-Pinion-Gear-Turbo-Optima-Salute-Ultima-Pro-/110989645429?pt=LH_DefaultDomain_123&hash=item19d77f9675
If you don't have a manual search for "Retromodelisme" they have manuals you can download.
Ebay is great for parts, there's heaps of parts available there, 99% of the RC stuff I get comes from ebay.
BTW, you can get reproduction OT-66 tyres from Marwan, he has his own website, also does repro bodies and decals.
Good luck with the rebuild.
Keith

Re: Old School Turbo Optima
Posted: Sat Jan 12, 2013 2:04 am
by Coelacanth
Nice Turbo! Btw chain drive wasn't an option, it was standard.

The belt drive conversion was an available and desireable option. As keithrc said, the OT-76 hard final pinion is the gear you want, but it's hard to find one at a "reasonable" price. People selling a single gear for 40 Euros is just crazy! But they *are* rare and everybody's looking for them.
Here's a tip: Keep your eyes peeled for a Thorp Dirt Burners hard pinion gear for the Optima; it's the same thing as the OT-76, but they turn up on eBay more often than OT-76's do. I've only ever found one OT-76, but I've managed to find 3 of the Dirt Burners gears.
You might contact transamman908 here, he was selling those...he may have one left.
http://www.rc10talk.com/memberlist.php?mode=viewprofile&u=1496
A few other comments: the Optima series weren't heavy; they were actually quite lightweight, one of the reasons why they performed so well. They compare favorably weight-wise with other 4WD cars from that day, and even close to the weight of some 2WD cars. Switching to the belt drive conversion helped reduce a lot of the maintenance as a result of the chain stretching; loosening those 8 or 10 frame-rail screws, removing the top chain cover, removing links, blah-blah-blah...the belt did away with all that maintenance.
Re: Old School Turbo Optima
Posted: Mon Jan 14, 2013 2:21 pm
by GeneralZod
I knew back then I should have bought the belt drive kit just to stash away until now. I already had to remove 3 or 4 links on the chain but it hasn't need adjustment ever since. A real fun thing to do....
I am afraid I can't pay 40 euros just for one gear but I will look into the Thorp alternative - thanks!
I hear you on the weight issue...I do seem to recall the old super champs were quite a bit heavier and the optima's were lighter. I just loved how well the suspension worked with the gold shocks on the optima. One of the things it impressed me the most was the handling along with the speed.
I went to my local hobby shop over the weekend and discovered an old Yokomo YZ-10 just sitting in the display case and I'm sure there was no intent to sell it. I did not see any price tag on it. Even back then and even now I would still love to have an old "Yok".
Re: Old School Turbo Optima
Posted: Mon Jan 14, 2013 3:06 pm
by DennisM
A hardened std. pinion ø 5 bore, 19 teeth 0.8 module or 32 dp (i.e hobby wing) will do the trick.
If You do a forum search for ot-76 in the kyosho section, you´ll find a link to it.
Otherwise there´s an ot-76 on ebay Belgium app. 29 euros. Ebay germany has the ot-41 at 19 euros.
I converted mine with a set of Mid diffs and belt.
Re: Old School Turbo Optima
Posted: Mon Jan 14, 2013 4:49 pm
by Coelacanth
I did my own home-brew of a belt conversion with my Barney build, you can find some details of the gearbox modding that's required here:
http://www.rc10talk.com/viewtopic.php?f=30&t=21530&start=67
That said, if you do it according to the instructions that came with the belt conversion kit, it's a tad more involved if you're trying to piece-meal it. You'll need an Optima Mid belt (I think OT-89), 2 Optima Mid diffs, a regular Optima/Turbo Optima gearbox that has a few pieces cut away and a hole drilled for the idler gear assembly, you'll need the idler gear assembly itself (though I've heard of people doing the mod without) and ideally, you'll want to fabricate a dust-block for the cut-away sections of the rear gearbox.
I added some pics that I used for reference, hope they help out if you're considering this mod.
The idler gear assembly is quite finicky; it includes a little shaft, some washers, a plastic ring if I recall correctly and a couple flange bearings--and it installs on either side of the dust-cover...all while having the belt and idler gear in position while bolting the 2 gearbox halves together. It's a bit of a pain, for sure.
Re: Old School Turbo Optima
Posted: Mon Jan 14, 2013 6:56 pm
by keithrc
Re: Old School Turbo Optima
Posted: Mon Jan 14, 2013 9:35 pm
by Coelacanth
No, they're no better than the stock gears, unfortunately...so I'd consider them overpriced.
Re: Old School Turbo Optima
Posted: Thu Mar 21, 2013 5:56 pm
by Super1080
I picked up a turbo optima a year ago it's in very good shape, for its age. Can anyone tell me the difference between a turbo optima and a optima
Re: Old School Turbo Optima
Posted: Thu Mar 21, 2013 7:16 pm
by kink
The Turbo had Gold bling on it, like shocks and motor guard. The regular one had red shocks. Both look very cool. The body and wheels are just lovely. The way the front shocks lay down is also very cool.
Re: Old School Turbo Optima
Posted: Thu Mar 21, 2013 8:41 pm
by Coelacanth
Super1080 wrote:I picked up a turbo optima a year ago it's in very good shape, for its age. Can anyone tell me the difference between a turbo optima and a optima
There were actually quite a few differences. As kink said, the Turbo had the excellent Kyosho Gold shocks; the regular Optima red shocks were crap. The shock towers, front & rear, were different with the Turbo, having additional mounting hole locations. The control arms also were strengthened with webbing and had 3 shock mounting holes instead of one. They also had mounting holes for front & rear stabilizers; the Optima didn't have stabilizers. The Turbo had a belly skidplate; the Optima didn't. The Turbo had a limiter gear (OT-74) to help deal with the gobs of torque from the Le Mans 240S (or 240SB depending on the kit, I believe) motor; the Optima's counter gear was just a plain gear on a solid shaft.
I think that about covers it.

Re: Old School Turbo Optima
Posted: Fri Mar 22, 2013 12:20 am
by keithrc
A couple other things, other than the body obviously there was the bigger regulater to handle the intended use of an 8.4 volt 7 cell battery pack, the 3 piece 1.9 inch 8 hole wheels and the also new OT-66 tyres. The lower guard was thicker than the original Optima too so it could take more of a hit before the front U-brace would bend or brake.
The Turbo or any other variant of the Optima did not come with a motor guard as standard, they were an optional extra.
GeneralZod, how's the rebuild going?
Keith

Re: Old School Turbo Optima
Posted: Fri Mar 22, 2013 12:54 am
by RichieRich
I love the Optima series. Here's my resto from years ago.

Re: Old School Turbo Optima
Posted: Fri Mar 22, 2013 1:47 am
by Coelacanth
That turned out sweet, Rich! Since we're showing off, here's my Optima, which I kept mostly stock...my others, not so much.
What it looked like after digging it out of a box after 20-some years showcasing my lame Mickey-Mouse home-built on-road body mounts:

After the resto:

Re: Old School Turbo Optima
Posted: Fri Mar 22, 2013 1:45 pm
by RichieRich
That looks great! Gold chassis too! What are you going to do for a body?