Turbo Optima build - Project Barney: Finished

[jwscab]

yeah, we have gone around with this topic before. Just curious of the dimensions, since he can measure them easily at this point. I don't know if the dimensions were ever published.

[Coelacanth]

yeah, we have gone around with this topic before. Just curious of the dimensions, since he can measure them easily at this point. I don't know if the dimensions were ever published.

I'll get that spec for you probably tomorrow night, Joe. I probably won't be home tonight.

[jwscab]

no rush man, appreciate.....have a good night

[Mr. ED]

http://www.rc10talk.com/viewtopic.php?f=29&t=15474&hilit=lazer&start=30

68mm is good for the rear, but you need some wide offset hubcarriers: like the optima ones
The 73mm ones are good for the front if you have rear arms in the front
(All the above is for 870C = NOT for 91 and later works)

[Coelacanth]

Here's the finished idler pulley dust-cover I fabricated out of leftover Lexan pieces. The Weld-On worked great, the 3 pieces seemed to cement together very well.

PulleyCover3.jpg (21.88 KiB) Viewed 1704 times

PulleyCover3.jpg (21.88 KiB) Viewed 1704 times

PulleyCover4.jpg (46.82 KiB) Viewed 1704 times

PulleyCover4.jpg (46.82 KiB) Viewed 1704 times

After making a mess in the past trying to seal my Optimas' chain-guides with silicone, I thought I'd share a simple technique I used to do a more tidy job. I simply mask along the outer & inner edges where I'm planning to apply the silicone, and as soon as I've applied the silicone (I use Household Goop), I remove the tape, which results in some nice, clean lines instead of having silicone drooping over the edges, getting everywhere on your car, hands, etc.

[Coelacanth]

Here's a progress shot, I was able to get quite a bit done this afternoon.

[nvxwax]

Looks killer, cant wait to see it finished

[Coelacanth]

I had an issue with too much positive camber on the front. The long control arm set I purchased came with its own C-carriers. I wanted to use these nice alloy purple ones (GPM #KF4019), however. They fit just fine and were otherwise an easy swap-in upgrade. I discovered that the design of the alloy C-carriers incorporated an angled region that acted as a camber block. Unfortunately the control arms prevented this region from moving within the outer notches of the arms to give me the slight negative camber I was looking for.

It was solved by doing a bit of grinding of the inner, upper edge of the foremost "notch". Fortunately, very little material had to be removed, so it shouldn't negatively affect the arm's structural integrity that much. The pics show where I had to Dremel a bit of the arms to allow the alloy carriers to rotate enough to resolve the camber situation.

The front swing shafts used are Kyosho 62.5mm units, the same length as the stock Optima dogbones. I had to switch the axles though, I wasn't getting enough axle thread to mount the front wheels. I believe I swapped the axles from LA258 60.5mm CVDs (which have 3 grooves in the axles) onto the bones of LA245 62.5mm CVDs (which have 2 grooves/shorter axles). The 62.5mm bones with the longer LA258 axles was perfect.

[Coelacanth]

I also got the steering linkage dialed in. I used HPI #93467 34mm titanium turnbuckles (which are actually 35mm) for the camber links and Schumacher #U1573 53mm titanium turnbuckles for the tie-rods.

I'm giving Barney some good clearance, I don't want this car knuckle-dragging and drooping in the dirt; I want it to stand tall and be solid-as-a-rock, for everyday bashing.

[Coelacanth]

I got a lot accomplished this afternoon! With the front end tweaking done, it was time to focus on the rear.

As mentioned before, the rear arms are el-cheapo $6 #DF2056 GPM arms (originally blue and were de-anodized, polished, and re-anodized purple.) They're almost exactly 5mm longer from pin-to-pin than stock Optima arms, which is great. I wanted to widen the track a bit to make a more stable ride. I found that 65.5mm Lazer universals were a tad too short, though; fortunately in anticipation of that possibility, I also purchased 68mm units, they were a perfect fit. I had to grind their flanges down like I described earlier with the 65.5mm joints.

The turnbuckles I used for the rear camber & stabilizer links are all 29mm titanium HPI #93464. The purple stab ball set is HPI #72302 with 4.8mm Delrin ball-ends. I used the top mounting hole in the rear Turbo Optima shock tower to mount the ball studs for the camber links so that they'd be more parallel with the arms & U-joints.

Rear stabilizer installed; had to drill & tap my own holes in the GPM arms for 3mm-threaded 4.8mm ball studs.

[Kayne]

That looks awesome. I love the colors .

[Jay Dub]

Currently doing something similar (axle/cvd install) on my pro radiant. The 62.5 mm bone, with the 3 ringed axle comes as a set for the original RB5. P/N UM 510. -Jeff

[Coelacanth]

For a change, I had some free time this evening and got around to fabricating a carbon fiber front shock tower so I could mount a pair of full-size Kyosho Gold shocks. Ideally, I would've liked the design to have a horizontal bridge on top to add strength, but the Optima body's front "nose" wouldn't have fit through the square hole. So, it was either cut off the Optima body's nose or use an open shock tower design. I'll see how this holds up, it's 3mm thick carbon fiber after all, it might be plenty strong. I can always re-fab another mount with a bridge and cut off the nose if need be.

As it is now, I like how trim it looks; the verticals are wider than the stock aluminum tower's are, and it's about 3 times as thick, and made from something a lot stronger than the thin aluminum front towers.

A couple other minor mods: these front arms had 3 holes for the shocks to mount into. I drilled & tapped my own holes about 5mm outboard of the outermost holes, to give the long shocks a flatter angle, allowing me to minimize my custom shock tower height. Next, my large-diameter springs & spring cups were binding with the control arms at the angles I was planning to mount the shocks. That was quite easily resolved by adding a purple spacer onto the shock shaft before screwing on the ball-cups. The outer diameter of the spacers fit perfectly inside the spring cup recesses and pushed the cups upward enough to clear the control arms...no more binding.

[EvolutionRevolution]

I hadn't noticed the spring color yet. Is that also custom-coated?

Where did you get the spacer?

[madmaxx]

Awesome work Mark !!!!!!