Drive shaft angle????
 

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:confused:

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??

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

Well done on opening that tin of worms! :lol:

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

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


Happy unhappy happy unhappy happy unhappy:lol:

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.

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.

And the CAT SX;)

I heard the production car is still 5 months away:thumbdown:

Cheers Chris D,

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

never touch it now.

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

Lee, just drive the thing! :lol:

G

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

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!!

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

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! :lol:

wow i actually understood all of this!

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

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:p it is in my work

:lol: 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

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:lol: The original point of them was belt tension though, people just used it as a tuning option

If its the same as the Mi3 (which I'm sure it is) then the belt tension remains similar and it is just the height of the diff which is altered. We used to mess around with this in the TC to help set ups.


Anyway, don't let mark win, get argueing with him!!!!:p

:lol:

Pretty sure any sweep forward or backwards will increase the lateral loading on the outboard bearings, but I don't think it will have any effect upon suspension:confused: I'd imagine that any extra rotating mass gain through mud on tyres, etc will amplify the effect.

Is it not the case that rasing/lowering the diff effects the CG and thats what people are feeling, not the drive angle? :confused:.

I dont think that statement is true, because you could alter the height of the hub and give the same effect, CL explaination seems to make sense and i trust chris, and CD backed it up. Its good enough for me:thumbsup:

No.

if the effect was as simple as the weight of it effecting C of G, we'd be putting lead high up on the tower rather than going through all the effort raising the gearbox.

I think you have that backwards Schlong, CVD's are the ones that want to straighten themselves under load ;)

when looking at the top of the car, if the driveshafts sweep forwards as they go outwards the car will want to rise when on power.

if they sweep backwards the car will want to lower its self when on power.

Hiya Rich!

Now you say it, I have a feeling you are right. Can anybody else confirm either way?

Got it, with some funky hand movement and chin scratching - I think I can remember it too...:lol:

CD, can you confirm the thing above, is it the Dogbone or CVD's which straighten up more on drive?

I'm pretty sure RL is right... CVD's are "stiffer" or want to straighten out more than Losi-style universals.

I seem to remember CVD's make the car square up much quicker (stiffer) than dogbones.

I love not having to worry about any of this stuff anymore.

i think its all part of the fun chris worrying about the little things.

It is facanating reading this thread ive always ondered what the diffrence between cvd's and dogbones are

A

This is interesting, i can see it now too, because im imagining CL`s hand movements:lol:

So shortening the wheelbase of the car is not just about getting more weight behind the wishbones, there is more to it. Nice to know this stuff:thumbsup:

Schlong, I'm sure Elvo told me that Gill Losi Jr set out to have zero dogbone plunge on the BK2.... :confused::confused:

G

there are so many 'simple' changes that we make that also change other things about the car that we don't or may not understand or realise, like you say, wheelbase does not just change the wheelbase, but also the driveshaft angle.

Then im pretty sure Elvo is wrong. It has a bucket full of plunge with those stumpy driveshafts. I know that as I drove one for quite a while - do you still have your BK2? I don't have mine otherwise id be double checking. :blush:

I seem to remember there being a lot of plunge.

they might as well have stuck a solid rear axle on the car the rear was that tight on power

Maybe I remember it the wrong way round. :(

I'm sure he'll pop by and let us know.

I don't have mine any more - converted it to a Hybrid - then a CR - then sold it. Stu and Damo still run them and like them! :woot:

I have a few bits left at home....

G

I can't get this :confused: Can you explain more?

The way i have it in my mind is:

Shafts angled / \ (backwards) means as they rotate they try and lift the rear end as they are pulling the wheels (sort of)

When angled \ / (forwards) in my mind they make the car squat more on power and drives the rear end into the ground


Someone correct me if im wrong:confused: