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[Nemotron]

I just realized there is no front differential on this car, doesn't that make it hard to control ?

[carloco8]

It has one-way bearings in the front hubs that allow one wheel to spin faster in the turns.

[Nemotron]

Is that better than a diff?

[carloco8]

It depends on what handling characteristic you are looking for, but from what I believe, there is no front diff option for this car.

[coralguy1]

As I understand it, 4 wd is only required when you are cornering, or the car loses traction. Otherwise, 2 wd is faster as the power from your motor is going to less moving parts. So, if you are in a straightaway and the car is tracking true, you are a bit faster. When you lose traction, or go into a corner, your car loses traction and momentum, then the chain catches up to the front end and it kicks in, becoming 4wd untill you hit the straightaway again. Anyway, that's how it was explained to me years ago.

[Mr. ED]

Ofcourse with the one-way being all the way at the end of the transmisson: right at the wheels there's not a lot of gain.
The motor is pulling the chain, pulley and dogbones (or U-J's) full time.
2 differences with a diff upfront are
- the inner front wheel can not turn slower than the rear wheels, which affects the steering characteristics.
- the friction on the faster wheel (outside) is not adjustable: less than compared to the friction for even the loosest ball-diff

[Nemotron]

Ok since I already am going to make a new carbon chassi and it is going to be a runner I think I will replace the 'gearboxes' with some modern stuff. The rear part will be easy but the front will be a bit harder. Anyone done this before?

[Mr. ED]

Interesting idea,
maybe you can keep the front gearbox housing but put a belt-drive diff in it from an optima mid. The rear end for the mid is very compact and will fit between the rear shock mounts also I think. If you use the 3mm pulleys of a lazer geardiff instead of the mid geardiff ones, you will have more opportunity to adjust the distance between the rear and front gearbox: mid only has 2 sizes belts and the teething is not a common kind

YZ10 870C transmission parts could work too: only using the diff upfront and full case in the rear..., but the motor sticks further out and could interfere with the trailing arms or shocks

If you don't have any parts to try it's a big gamble: you may end up with lots of stuff that just not fits: for example because the ball-ends of the 834 dogbones don't fit the kyosho cups etc.

[Nemotron]

Maybe I can weld two different dogbones together, universal axles would be better tho I went to the local junkyard and got some 3mm aluminium today to make the piece that holds the rear shocks and body. Anyone know what kind of shocks would be good for this, there are alot to choose from , but those that came with the car are too short. I see some people use old RC-10 shocks.. Maybe something else would do, need to have two at the rear and one smaller one up front..

Will put my Scorpion project away(in a box at the loft) for a while since this is much more interesting right now

Øyvind Johansen

[uzzi]

Perhaps I can chime in on this one-way discussion ….understand the nature of a 4wd car would generally cause it to understeer into a corner at speed. What normally happens is when power is applied the one way ‘locks’ giving you full-time 4wd. When you back of the accelerator it switches to being 2wd……hence it is a primarily a part-time 4wd drive system. The development of the one way system to enable quicker cornering speeds for 4wd cars. However, it’s not a cure all as it does make for a very nervous, twitchy car and is only suited for certain conditions. Tracks with plenty of flowing, high speed sweepers would suit one equipped cars (esp. stock motor touring cars). Low grip and technical tracks (that require braking) would mean you are less likely to use one-ways.

Below are some of the combinations that manufacturers and drivers have come out with.

(1) Front one way on drive shafts with solid front (spool) / rear diff (Schumacher cat XL)
(2) Front one way on drive shafts / front and rear diff (Schumacher Cat XLS)
(3) Front diff / one way centre layshaft / rear diff (Yokomo BX)
(4) One way on drive shaft / one way centre layshaft / rear diff (Touring cars)
(5) One way on drive shaft / one way on rear drive shaft (combination used by Gil Losi on his 834B)

One would be very brave to run the combination Gil Losi ran as it means he ran pretty much without brakes!!

[GJW]

got some potential for sure nice pick-up brother