Page 1 of 2

My Turbo Optima (mid-motor conversion):12th Aug,2009 updated

Posted: Mon Aug 10, 2009 3:20 pm
by minimini
In the old days ............because of the geographical reason........on-road buggies were very popular in Hong Kong..........Turbo Optima was one of the best at that time.......... :D

Lucky enough to buy a set of Turbo Optima "mid-motor conversion kit" from a local 2nd hand R/C shop before........which was designed by GPM I think (appeared few years before the Optima Mid) .............combining with a spare-part car..........hope to make it a runner again some 20 years after its production........ :mrgreen:

stay tuned......... :)

picture courtesy of http://bbs.rc-evo.com (for the first pic)

Re: My Turbo Optima (mid-motor conversion):11th Aug,2009 updated

Posted: Tue Aug 11, 2009 1:59 am
by RETRO R/C
OMG that is freaking sweet. I remember seeing one of these in a Japanese magazine in 85 or so. The guy that had the magazine said he was going to do this himself (he was an engineer) - and I was in awe of him and the mag (impressionable kid).

The fact that you have one in the flesh is awesome - I always thought they were only a prototype.

I have a Hirobo Zerda with a very similar set up (high mounted mid motor), but it is "home engineered" as opposed to finished as well as this one.

FANTASTIC stuff.

If you get the time - I would love a template of those modified motor and support plates! ;)

This will be a thread that watch with great interest.

Cheers

Darryn

Re: My Turbo Optima (mid-motor conversion):11th Aug,2009 updated

Posted: Tue Aug 11, 2009 7:54 am
by mrlexan
Indeed, very cool. Never knew such a thing existed.

Re: My Turbo Optima (mid-motor conversion):11th Aug,2009 updated

Posted: Tue Aug 11, 2009 12:15 pm
by minimini
Thanks for the inputs........ :D

From my memory.........this was one of the best "inventions" by GPM in the old days .........not just a copy cat at least.............(actually this company did not have many good products in my opinion, or maybe they just exported those up-to-standard goods overseas, leaving those with poor quality in Hong Kong local market........rather disappointing........) ......

But the main drawback is the high motor CG position ........that made the car got a lot of rolling at corners.........a bit like the Marui Samurai......... visual excitement --> good..........actual performance --> errrrrrrrrr........ :mrgreen:

As you can see in the pictures.........I am going to use the BigWig wheels in this car ..........which used to be a very popular modification in Hong Kong at that time........

For the body shell ........I got both the Kamtec & Marwan ones indeed..........but I heard from someone that the Kamtec one is around 4mm shorter than the original ........for this project.......as the rear part needs to be cut out........so it makes no difference of using either shell......... I'd better reserve the Marwan one for my original rear motor-mounted Optima projects.............

Re: My Turbo Optima (mid-motor conversion):11th Aug,2009 updated

Posted: Wed Aug 12, 2009 6:23 am
by Mr. ED
Nice to see this, never seen it before or even heard of it. The world has become so much more accesible with internet. Noway you'd ever have found out about this option back when it was released; unless you lived in Asia.

Funny you mention the bigwig wheels as a hop-up.
I never had those, but if they were anywhere comparable to hotshot wheels... such disaster!
The offset was far less than kyosho's wheels, which would leave you with a narrower track. And the hotshot wheels were terribly wobbly: as if forcing the tires on already deformed them :lol:
and as you tightened the wheelnut and drove it around you d'notice the flat becoming increasingly hollow: in the end I was fearing the knobs on the hubs wouldn't grab the holes in the flat side of the wheel anymore.
Finally I found a pair of You-G wheels which provided more offset and were much stiffer, but I only had enough pocket-money for 1 pair :lol: :lol: :lol:

Re: My Turbo Optima (mid-motor conversion):12th Aug,2009 updated

Posted: Wed Aug 12, 2009 11:42 am
by minimini
just have a quick look at the store room today.........found a set of BigWig wheels & tyres...........a Kamtec shell with driver doll........an orange Trinity motor (which is using small brushes like Checkpoint motors).......some electronics.........need some time for them to be binded altogether........:)

Re: My Turbo Optima (mid-motor conversion):11th Aug,2009 updated

Posted: Wed Aug 12, 2009 12:45 pm
by minimini
Mr. ED wrote:Nice to see this, never seen it before or even heard of it. The world has become so much more accesible with internet. Noway you'd ever have found out about this option back when it was released; unless you lived in Asia.

Funny you mention the bigwig wheels as a hop-up.
I never had those, but if they were anywhere comparable to hotshot wheels... such disaster!
The offset was far less than kyosho's wheels, which would leave you with a narrower track. And the hotshot wheels were terribly wobbly: as if forcing the tires on already deformed them :lol:
and as you tightened the wheelnut and drove it around you d'notice the flat becoming increasingly hollow: in the end I was fearing the knobs on the hubs wouldn't grab the holes in the flat side of the wheel anymore.
Finally I found a pair of You-G wheels which provided more offset and were much stiffer, but I only had enough pocket-money for 1 pair :lol: :lol: :lol:
Erik.........you are quite right ........I think this conversion kit was available in Hong Kong only (because GPM was a tiny little LHS at that time, not even got any overseas trading)..........

for using the BigWig wheels...........mainly for "cosmetic reason"......... :) ..........you can add spacers over the original wheel hexa to compensate the off-set problem..........or simply change to a thicker wheel hexa (Kyosho got this).........of course there would be slight difference in using hop-ups/ modifications in different localities...........that is "preference"...........that is "trend".......that is "World" ......... :lol:

the You-G wheels.........I got 6 in total (4 painted with black words & 2 with red ).......... got them in a bulk trading long time ago .......... :D

Re: My Turbo Optima (mid-motor conversion):12th Aug,2009 updated

Posted: Wed Aug 12, 2009 1:01 pm
by RichieRich
This is really neat. I'd love to see it drive.

Re: My Turbo Optima (mid-motor conversion):12th Aug,2009 updated

Posted: Thu Aug 13, 2009 1:36 am
by Jay Dub
I seem to remember an american company that offered a conversion kit for the optima series of cars. Anyone remember who it was?

Re: My Turbo Optima (mid-motor conversion):12th Aug,2009 updated

Posted: Thu Aug 13, 2009 4:18 am
by Mr. ED
Jay Dub wrote:I seem to remember an american company that offered a conversion kit for the optima series of cars. Anyone remember who it was?
I remember a company offering moterplates to allow mounting 2 moters... but I don't recall the name, nor if the optima was one of the cars in their line.

Re: My Turbo Optima (mid-motor conversion):12th Aug,2009 updated

Posted: Thu Aug 13, 2009 6:14 pm
by optimaforever
very interesting modification on the optima!
I confirm that Kamtec optima reproes are several mm shorter than original. Always drill the holes BEFORE painting and making the deco. Otherwise, ... surprise, surprise :lol:
I'd be interested to have more info on the parts... Do you have a manual? an axonometry?
That's funny that they kept the original OT-57 shock stay though :wink:
And I suppose it works with the belt as well? or is the chain length modified?

Re: My Turbo Optima (mid-motor conversion):12th Aug,2009 updated

Posted: Fri Aug 14, 2009 12:15 am
by minimini
optimaforever wrote:very interesting modification on the optima!
I confirm that Kamtec optima reproes are several mm shorter than original. Always drill the holes BEFORE painting and making the deco. Otherwise, ... surprise, surprise :lol:
I'd be interested to have more info on the parts... Do you have a manual? an axonometry?
That's funny that they kept the original OT-57 shock stay though :wink:
And I suppose it works with the belt as well? or is the chain length modified?
This GPM conversion kit did not have with any manual........ :shock: ........all the components (more correctly, the motor plate & upper deck only, no screws no washer nothing) were packed in a small plastic bag ...........I remember in the old days........when you bought this kit in the GPM shop......the shop owner will teach you how to install .......& he will even take out his own car for your reference........chatting with you........this purchase will cost you at least one hour's time..... :o

The chain length is same as original (the belt kit also fit this).........you need to drill two extra holes in the rear gear box to anchore the shock tower.......but the original rear shock tower was far to weak ........so I double it up as you can see......or you can use some aftermarket FRP towers by CRP , JG or YSP.........

Re: My Turbo Optima (mid-motor conversion):12th Aug,2009 updated

Posted: Fri Aug 14, 2009 5:17 am
by optimaforever
Thanks for the precision :D

Re: My Turbo Optima (mid-motor conversion):12th Aug,2009 updated

Posted: Fri Aug 14, 2009 1:04 pm
by Mr. ED
YSP???
Never heard of them. Do you have some info or pictures of parts they made?

Re: My Turbo Optima (mid-motor conversion):12th Aug,2009 updated

Posted: Sat Aug 15, 2009 12:55 am
by minimini
Mr. ED wrote:YSP???
Never heard of them. Do you have some info or pictures of parts they made?
this is one of the YSP products.........the chassis under-guard for optima ........

you can also see some other YSP products selling in ebay........:)

http://toys.shop.ebay.com/i.html?_nkw=ysp&_sacat=2562&_trksid=p3286.m270.l1313&_dmpt=Radio_Control_Parts_Accessories&_odkw=&_osacat=2562