Mid motor chain drive Optima is it possible?

[keithrc]

This might be a weird idea but I remember thinking of this when I was younger and still had my original Optima. Would it be possible or, even feasable for that matter, to convert a MK1 chain drive Optima to a mid mounted motor?

I'm thinking keep the chain drive and the chassis rails to keep it as close to a MK1 as possible but with the motor mounted in front of the rear wheels.

Looking at one of my cars, you'd oviously have to disregard the radio plate or at least trim off a rear section of it, the motor plate, shock tower and plate on the other side of the gearbox would need to be redesigned. Then there's the issue of weather the motor would fit between the upper and lower chain guides (maybe use a Mid gearbox and motor mount plate and shock tower?)

Just throwing this out there for you guys that are into building the crazy custom cars and see what you think. Is it worth pursuing or too crazy to consider? Maybe someone's attempted it in the past?

BTW, I already have 7 Optima Mids.


Keith

[losiXXXman]

There's actually a kit that des this conversion. It's probably EXCEEDINGLY rare at this point, though. I've seen MIP 410 legend car and even 1 kit come up on eBay over the last couple years, but never one of those optima kits. I think terry.sc has one in his TC Showroom, but it may be retror/c.

[keithrc]

That's interesting, can you give me a link to terry.sc's showroom?


Keith

[j0pp3]

Here is a conversion that is stated to be made by GPM:
http://www.rc10talk.com/viewtopic.php?f=30&t=11249

Looks cool but what about the cg...

[losiXXXman]

I tried searching on TC, but couldn't find the car. Look like it appeared after all though. thanks jopp3! Yeah, that car probably would have been a LITTLE top heavy.

[Coelacanth]

That's cool, I'm not sure I'd want the motor mounted up so high, though, as j0pp3 said.

As to how to do that conversion, the more I think about it, the more work it would seem to take. Optima Mid gearbox & motor plate would need to be mated to the original Optima's frame rails. You'd have to modify the Mid diff so it had a chain sprocket instead of the belt, but that could probably be done with some modding, not sure about spacing though. Maybe just swapping around some diff halves would do the trick. I think a bigger headache would be all the "finicky details" stuff, like the chain guides & covers, some way to adjust chain tension, mounting the rear suspension arms, etc...but of course, anything can be possible if you set your mind to it.

[ROH73]

There was this AJT conversion, as well. I've never seen one in person.

[Coelacanth]

I'd love to see better pics of that, I can't quite make out what's going on there.

[keithrc]

Thanks for that link j0pp3, I wouldn't have thought of mounting the motor on top though.

ROH73, that's more what I was thinking of, are there any better pics and details of that kit?

Keith

[ROH73]

Keith,

I don't have any more info on that conversion...I just scanned the ad out of an old rc magazine. I would love to see the details as well.

[keithrc]

Thanks anyway ROH73, I tried enlarging that pic but it gets too blury to make out any finer details. I'm curious about how they got enough clearence for the motor between the chain guides, maybe that kit requires the guides to be taken out alltogether.

Actually, all this talk of motor conversions reminded me of an Optima converted to nitro power I saw pics of a while back.

http://theoptimahouse.blogspot.com.au/search?q=Optima+gas


Keith

[j0pp3]

I think the reason for a top mounted motor is the "easy way out". I mean if the motor is position either at the rear or on top you can probably still use most of the original drive train, chain with standard length and so on. The AJT conversion looks much more sophisticated. I would also like to see more about that solution.

Closest call from Kyosho is probably the Rocky model but that's also a completely different car and maybe not comparable.

[losiXXXman]

The layout of that second one looks a lot like an AYK Pro Radiant. Maybe the secret es an extra chain so that you can add enough links for some slack to go over and/or under the motor, and then some chain guides/tensioners... either way, it looks like it would have been a lot race-ier than the GPM one. Of course, that kit probably predated the Mids by not very much, and production was therefore low number before discontinuation settled in. too bad though..

On a side note, with all the desire out there for 4-10 legend MIP cars, I've been considering an upgraded/dated Optima/Ultima Project. Rear motor 4wd using Ultima drive train, front end from a mid, all linked up with a custom fiberglass or graphite plate double decker. Main things I need to get to start mocking is a Mid front trans case, pulley and a LWB belt.

[terry.sc]

I think terry.sc has one in his TC Showroom, but it may be retror/c.

Nope, I don't have one but back in the day I did look at a home made conversion as it should be pretty simple to do. I drew up a design when there was news of the mid prototypes being developed, but as I was pretty successful at the time with my modified Optima I never had a need to build it and as soon as it was available I bought a Mid. It would be simple to do, a new pair of gearbox side plates, a new top deck and a pair of flanged bearings to act as a roller guide above the motor for the chain to pass over, and a new hole for the chain to come out the front of the gearbox. The hardest parts of the job are sorting out the shock mount and an external gear cover.

Thanks anyway ROH73, I tried enlarging that pic but it gets too blury to make out any finer details. I'm curious about how they got enough clearence for the motor between the chain guides, maybe that kit requires the guides to be taken out alltogether.

The upper deck isn't flat like the normal Optima, you can see the battery pack is sitting at an angle and it is attached to the upper deck giving away that the upper deck slopes up at the rear. This means either the chain is raised up over the motor with it running to the front at the same angle as the deck like the Pro Radiant, or with the extra clearance under the battery there is the possibility the chain could be lowered to run under the motor, battery and servo like the Zerda. The simpler way is to run above the motor as it means no changes needed at the front gearbox.

[losiXXXman]

After I posted that I checked you and Retro's TC showrooms, and realized it wasn't either of you. Sorry. I look at SO much stuff on here, and there, and everywhere.... I can never remember which belongs to whom? I'm glad someone knew where it was! Thanks J0pp3.