Drive shaft angle????

[Lee]

Right, i have heard that the angle of the drive shafts have a massive effect on the way the car handles. How?? can someone explain, some yank was going on about drive shaft plunge and you want as little as possible on rutted tracks, but i am not sure why it would help and what to alter to change this, i thought the x-6 was the only car with an adjustable height gearbox or am i missing something

[mattym0310]

It adjusts the point of contact between the the driveshafts and the outdrives. In theory if this point of contact is raised forward bite is increased and you get less side bite. lowering the point of contact does the opposite; more side bite, less forward.

I thinkthis is correct??

[Lee]

So if the hub end is raised, less side bite and more drive??

[Chrislong]

Well done on opening that tin of worms!

The drive shafts always want to run in a perfect straight line to the diff, the faster the car the more that effect will occur.

So, running unhappy driveshafts / \ will mean the car will squat more due the the drive shafts pulling the wishbones up and in effect, softening the rear suspension. This is why raising the gearbox on an X-6 gives more drive.

Running happy drive shafts \ / will do the opposite.


With CVD's this effect is less, so when driving through a corner and the driveshafts are like this \ \ the wheels can still spinup without the straightening force as much as Losi dogbones will.... this is how the two driveshafts are used as a setup option. (and to be honest, I can't feel the difference).

There are so many variables, and if your bones and outdrives are worn - there'll be no benefit of using this as a tuning option as the driveshafts will always want to run in the peak of the worn section and lock the suspension solid (almost) when lots of torque/revs are going through the wheels. Therefore its also important to not have any tight spots on anything that is meant to move, and I mean ANYTHING.

Chris

[Lee]

Cheers for that chris, very well explained, i understand why now


Happy unhappy happy unhappy happy unhappy

[Chrislong]

Originally Posted by Lee

Happy unhappy happy unhappy happy unhappy

That'll be the ripple section, only accelerate when unhappy! or if not sure.... nail it anyway, it'll be right 50% of the time.

[Chris Doughty]

bone plunge is how much the end of the dogbone moves into the diff outdrive as the suspension moves.

as little as possible means free'er moving suspension when on power. and it will feel more similar on and off power - a lot of plunge stiffens the suspension on power

if you have a lot of plunge then the effect that Chris mensioned above is amplified.

you can normally change the amount of plunge by making your inner hinge pin as close to the outdrive as possible, and also the inner hinge pins as close to the 'ball' of the bone as possible.

[stegger]

Originally Posted by Lee

i thought the x-6 was the only car with an adjustable height gearbox or am i missing something

And the CAT SX

[Lee]

Originally Posted by stegger

And the CAT SX

I heard the production car is still 5 months away

[Lee]

Originally Posted by DoughtyUK.net

bone plunge is how much the end of the dogbone moves into the diff outdrive as the suspension moves.

as little as possible means free'er moving suspension when on power. and it will feel more similar on and off power - a lot of plunge stiffens the suspension on power

if you have a lot of plunge then the effect that Chris mensioned above is amplified.

you can normally change the amount of plunge by making your inner hinge pin as close to the outdrive as possible, and also the inner hinge pins as close to the 'ball' of the bone as possible.

Cheers Chris D,

Is this something you play about with or is it just a case of get it right and leave it alone

[Chris Doughty]

never touch it now.

my findings were from back in the XXX4 days (have a look in the Losi section at Stanleys post)

[Northy]

Lee, just drive the thing!

G

[Lee]

You know i cant to that G, i have to know every inch of the car and why things are the way they are

[mark christopher]

Originally Posted by stegger

And the CAT SX

but it doesnt, the diff height is adjustable, not the gear box, seeing as its not gear driven but belt driven it dont even have a gearbox!!

[Chrislong]

Originally Posted by DoughtyUK.net

if you have a lot of plunge then the effect that Chris mensioned above is amplified.

As a good example, this is why the Losi BK2 performs as it does. It has shorter driveshafts and longer outdrives and the plunge was massive.

Resulting in huge amounts of traction in a straight line, but with that comes a bucket full of understeer when on power. Suited me like that - point and squirt.

Chris

[Chrislong]

Originally Posted by mark christopher

but it doesnt, the diff height is adjustable, not the gear box, seeing as its not gear driven but belt driven it dont even have a gearbox!!

Its the height of the diff which makes the difference. Ride height remaining the same, if diff is raised than outdrive unhappy and traction increase. Whether we say raised diff or raised gearbox makes no difference - same effect either way.

Its a box which holds a gear driven by a belt. its a gearbox!

[tonymon]

wow i actually understood all of this!

id prefer to have my car with happy driveshafts, its not worth having a car thats sad!

[mark christopher]

Originally Posted by Chrislong

Its the height of the diff which makes the difference. Ride height remaining the same, if diff is raised than outdrive unhappy and traction increase. Whether we say raised diff or raised gearbox makes no difference - same effect either way.

Its a box which holds a gear driven by a belt. its a gearbox!

i know i was making the point that the schunmacher does not have a gear box, 9as the poster said the schumacher had adjustable gearbox height) altering the diff hieght is the end result your after


im sure schumacher wont call it a gear box, more a diff housing, even then the housing does not move, the diff bearing eccentrics move the diff up and down, the gear box is fixed!
Besides is a belt driven "gear" not known as a pulley it is in my work

[Chrislong]

tut, your in one of the argumentative moods aren't you? okay okay, your right! ha ha.

I didn't think the purpose of the eccentric cam bearing housing for the pulley box was there to serve the purpose of diff height as a setup aid, but for belt tension. If Mossy or MattW can explain if the purpose is belt tension or diff height adjustment?

Also, having the driveshafts sweep forward or back causes an effect - I am lost at this point though. Can somebody explain?

Chris

[Lee]

Chris, when running the MI3 we could alter the diff height, it was either high or low, it was on a cam and belt tension didnt really matter as it was flat out everywhere The original point of them was belt tension though, people just used it as a tuning option