Back to the Optima (suspension)

Ok, i love back to the future, since it was so 80's. So thats how i came up with this title. I was supposed to race my Mid in a race last week but i broke one lazer ZX front c hub while casing a big jump. I got so fed up and went back to the original Optima Mids suspension. One of the biggest reasons was i had  a pair of A & L alumimiun C hubs with bearings and i think i could practically bulletproof the suspension with these c hubs.

The A & L C hub, with 4x8x9x3 flanged bearings.
Thats a ZX-5 plastic knuckle. i ground off 2mm from the top of the knuckle to be 20mm then only it could enter the c hub.

another view.

Rear Optim Mid Suspension with the arms flipped so that i can place the shocks at the rear like the lazer. Thi is done so that i can clear the new layshaft .

Position of shock on shock tower.

I tried the car today on the terrible offroad track and it was much better than before, simply because i removed the durango shock boots that was interfering with smooth suspension movement. the Mid could clear the big jumps most of the time and landings were good. It also handled the bumpy sections rather well. Of course the tree roots still posed a problem, but the car was definitely better. Also since i was using modified kawada touring car knuckles, the mounting for the kingpins was too short causing the kingpins to dislodge itself and ending my testing. i went home and then decide to grind off the ZX-5 knuckle by 2mm at the tops so that i can slide it into the c hub.The zx-5 kunckles felt a lot more secure, and the kingpins felt secure in them too. i think i pretty much nailed this problem with this solution. will test again the next week.

Big Bores, Such a boar??

I finally tested the big bores on my Optima, and at first i had 20wt oil in them , and they were too soft. it was bottoming out too easily. i took the advice of some drivers at the track, and put 50wt oil in the front, and 30wt in the rears. The car is now much easier to drive and i am finally clearing the jumps, small and big most of the time ! Before it was only some of the time. I also tried to place the front shocks to give it more ride height and droop, and i found that the car goes over the small bumps much better instead of nose diving, so it goes through the whoop de does much quicker. I also learnt a technique to clear the big jump, go up the hill quickly build momentum to the jump and at the end of the jump brake, the car will land nicely on the backside of the landing jump. However i still find the car under powered with a 10.5T, so the next step is to get a 9.5T or 8.5T. Also it seems my 5 year old Speed Passion GT1.1 ESC is finally giving way. after a few hard bumps, the calibration of the ESC went off. I had to recalibrate a few times. Now i have to buy a new BL sensored ESC and motor for my buggy, more expense needed, becuase of the coming race on the 25th. I managed to break a front right lazer arm and bend the RCPS titanium hingepin from hitting the backside of the jump squarely. So now i place ZX-5 arms and uprights on the front end of my Mid. I will also drill a few more holes on the rear of the James Instone shock towers to give the rear a little more ride height and droop becuase it seems to snag at the cement hill bank while going up, losing some speed build up for the big jump. will report back in 2 weeks. In the meantime i will be driving my Kawada SV-10 Alcyon II this weekend and giving my Optima Mid a rest. Dont worry it will come back with a vengeance !

Some Old Pics

Here are some old pics of my cars, many of  them of the optima mid

New Videos Slipper Clutch and OT-66

OT-66 has arrived, Marwans repros

I got My OT-66s and i cant wait to test how they work against new tech tyres.

Optima Mid Custom Body with Original rims and OT-66 tyres

Turbo Optima Mid Special Body with Original rims and OT-66 tyres

Which one looks better? i alternate between both bodies since the undertray is the same.

I tested the tyres on a slightly damp and muddy track, and with some sections of grass, and i am glad to report that these tyres work better than modern proline M3s on that surface. This is becuase the M3s have short spikes, becuase of that, when the mud covers the tryes, there are no more spikes digging through the earth. Becuase of that the car understeers. The OT-66 on the other hand is of a harder compund and the spikes are long and far apart, so mud cant really obscure the spikes, so they dig right into the earth, giving your car more grip. not only that, becuase the fronts and the rears are wide, my car actually had more steering than with the modern tyres ! i will try these tyres in the next race in subang if the track is wet. Even if the track isnt wet i might use it for 1 heat just to try them out.

With Optima Mid Custom Special Body, in the dirt !

Optima Mid Custom Special

Broken Parts - Watch Out

Over the course of the first post on this blog until now, i have damaged and broken numerous parts on the Optima Mid. I will let you know which parts broke or bent and how to remedy them.

1. Graphite Chassis. Do not use this chassis if you intend to race hard, it will snap, look at this pic.

All i did was jump high and land hard, and i did slammed into hard packed jumps many times too. Graphite will crack, take my advice, stick with the OT-122 Aluminium chassis. Its heavy but it will never snap.

2. Stripped front gearbox threads. Fixing it is simple, see my previous entry about the bolt and nut method to secure the gearbox. Dont forget to seal the holes with silicon.

3. Cracked rear gearbox at 2 wingmounts. After several months of tumbles and rear wheelies, the wingmounts still last, but it teared the rear gearbox wing mount, exposing the rear tranny to dirt, and i have to open everything again to clean them up. Since i am using lazer ZX-R shock towers, i will replace the wing mounts with ZX-R mounts part number UMW-1. I think i should rename my car Turbo Optima Mid Special ZX-R.

4. Bent inner hingepins. Do yourself a favor, buy RCPS titanium hingepins ,and drill out the arms with the drill bit and instructions given. These hingepins wont bend.

5. Cracked rear gearbox mounts

I tried a new way to hold the rear arms without using e clips on the inside, by using airplane wheel retainers in the arms and e clips on the rear. So what happened was i was at glenmarie track jumping the car hard and hitting track barriers, and then suddenly my rear arms look like they came off. To my horror i found the screws holding the rear arm brace is still intact, but the plastic thats its screwed into, detached itself from the gearbox!

The solution to prevent this is simple, place pack the eclips at the rear of the arm brace, that way the load on the arms will be shared by the inner arm brace and not all loaded on the outer arm brace.

My Video

This is the link to my new video.

Snapshots from my video