"Doggy Bag" YZ-834b runnner build

[Mr. ED]

Make sure you mount better tires than your friend and you win half the battle straightaway

[Dadio]

That should be easy , he's famously tight fisted so he'll just mount the kit tyres and after that the cheapest he can find

[Lonestar]

You should leave the chassis alone. It helps to keep a low cg. Back in the days the minimum legal weight was 1.7 kg drive-ready.
With todays motors esc and lipo technology the extra weight wont hurt.

This. on the videos your 834 looks like it's handling properly, as opposed to how it should handle normally. The heavy chassis and low cg is probably one of the reasons why. I would only focus on unsprung mass, not the chassis

Congrats for bringing this project to life and thanks for sharing it with us

Paul

[Dadio]

The trailing arms are rather heavily made , roughly the same outside dimensions as stock but made of solid acetal and alloy , they could stand to loose a fair deal of weight and that should translate into better handling , there is a lot less of the front top arms to begin with so less of an improvement ,I'm kind of tempted to replace them with ball joints and turnbuckles as seen on Gill Lossi's 1985 IFMAR car , that would be lighter and kind of cool without being expensive to do and believe it or not this is meant to be a budget build to use up some spare parts ! It's never intended to be a concourse car but one I can drive without fear of damaging it .

[Peakey]

Ive been thinking about using that setup on my upper front arms, I also found a nip slipper tonight that I had to buy

[Dadio]

I saw that as well on eBay , your pockets are deeper than mine if it's the same one , I couldn't see the slipper pads in the bag , only the sprocket, shaft,spring and washers , did they have slipper pads or just washers onto the sprocket ?

[Dadio]

I just weighed the trailing arms and they are 42.5g a piece ! Off to the workshop now for a little turning and milling .

[Dadio]

Ok so after re turning and milling the rear arms are 34.5g , that's 8g off each , still heavy but a lot better .
Before

After

So after the rear arms the next heavy bit was the rear gearbox guard that I made out of 3mm aluminium weighing 29g .

I was thinking of just drilling it but then i remembered the Kydex i got for the bumper , still 3mm thick so good and strong so this is what i made .

i integrated the mount's for the roll bar braces to further reduce weight and at 14g with the ball studs fitted it's just slightly under half the weight
Between the trailing arms and the rear guard that's a reduction of 30 grams , not too bad !

[Dadio]

A little off the top deck .
Before

After

Only 5 g but it all adds up and this is high up so helps stability too.

[Dadio]

I finally found time to drive the two cars back to back , the new one is way faster and has way more steering sensitivity but lacks the sole of the original , I love the way the old car drives even if it's slower , the new one drives so differently it's almost like a completely different car , not sure what I really expected from the new one or what I really wanted either , I think I succeeded in the engineering but I might have removed too much DNA

[Dadio]

I look her out for a spin along with my Zerda yesterday and I'm getting used to how she runs , it's way more stable than stock , very fast and left the Zerda for dust

[Mr. ED]

I'd love to try it out. These were sold by graupner from germany into belgium. In the very early eighties I didn't have a car yet but there was a big cross drawn in my catalog righr next to this car.
Yours sporting these improvements only make it more desirable in my eyes

[Dadio]

I'm really pleased with how it goes , very different to stock and the upgrades make it much more predictable in handling but I'd never have change my stock one in any way , just like you this was a dream car when I was a kid and the image in my mind was a stock version not a modified one !
I found quite a few parts in Graupner brand , I just found the rear chain guard that I've been looking for for over two years , that's going on my original one , that just leaves one part to find to complete my stock version , the holy grail , the top deck/chain guide , they are either non existent or very , very expensive

[Dadio]

You know when your a little obsessed when you do a Google image search for Yokomo YZ-834B and 21 of the pictures you find are yours

[Dadio]

A pair of original plastic C hubs arrived today to replace the gold alloy ones , the alloy ones are 4g each , the plastic ones only 1g so that's another 6g off the weight of the front suspension , also fitted one upper suspension arm to replace one of the alloy ones for a saving of another 5g so I'm now approaching my 50g target .