2wd to quadra?

[Tony]

This is best answered by Sibley, but being a viscous front diff, it tends to switch the power in pairs. You can make it rear wheel drive by changing the oil. If you just removed the front drive shafts there would be no drive. I know its a little more complex than that and I may have made a couple of errors.

 

[danb]

Whats a viscous front diff?

I believe its a 65/35 split, but all power can go to the front, and likewise it can all go to the back.

 

[Haz]

so it works kinda like an auto box, as such, centrifugal force? so thinner oil would cause less friction in the box sending all the drive to the rear wheels. but if you left the cups in for the front wheels and took the shaft centres out they would just spin round, like the wheels are in the air causing the oil to have the same effect?

 

[Tony]

Whats a viscous front diff?

I believe its a 65/35 split, but all power can go to the front, and likewise it can all go to the back.

Dan, when you take the box off you will see. On the back of the box is the diff.

so it works kinda like an auto box, as such, centrifugal force? so thinner oil would cause less friction in the box sending all the drive to the rear wheels. but if you left the cups in for the front wheels and took the shaft centres out they would just spin round, like the wheels are in the air causing the oil to have the same effect?

Haz, basically yes. Most of the time its a front wheel drive, but when needs be it can move up to 35% of its power to the rear.

 

[DaveL485]

Haz, basically yes. Most of the time its a front wheel drive, but when needs be it can move up to 35% of its power to the rear.

God dammit Tony, stop being wrong you noob!

The Quadra system is like a 2wd setup, twice. The diff at the front works like a 2wd diff does. The diff at the back works the same. They are linked by a viscous coupling, which splits the drive 65% to the front and 35% to the rear.
In slip-conditions it transfers the drive to the wheels with the most grip, and can do so up to 0/100 or 100/0 percent split. This means taking the front shafts away would force the drive to the back all the time- but the viscous coupling wouldnt like that too much.
There is also a locking function built into the rear diff, and in first and reverse you can lock the diff completely. Think LSD, but not LSD more like NO slip diff. Great for donuts.
So- thats why Quaddie's come out of corners like a slingshot- even though there isnt an LSD, as soon as the front inside wheel tries to spin it loads up the back a bit and shoves you out the corner.

 

[Tony]

Sorry Dad. Lol. It's been a long time since I had to think about how a quadra works. I had better get revising as mine should be on the road tomorrow. :0)

 

[Haz]

So it could be locked in permanent rwd then? And could the coupling be fitted backwards so the split is more to the rear? These are just curiousity questions, they look to work very well in the vids I've seen and would guess it would feel more like a fwd car, until you ended up in that sticky situation and it pulls you out.
Sounds good tony, recon your car will have it's headlights shut after being in the dark so long lol, get practicing too, I'm looking forward to a very spirited drive on the road of your unit

 

[danb]

lol @ viscous front diff

 

[DaveL485]

So it could be locked in permanent rwd then? And could the coupling be fitted backwards so the split is more to the rear?

Technically yes, but expect something to fail quite quickly. Coupling backwards- no, thats just silly. Besides the drive to the rear sits behind the front diff.

You could, however (and ive been meaning to look at this properly) alter the viscosity of the fluid in the viscous coupling to change the standard drive split front>back. I'm not sure on the validity of this as a task though as its transfer capabilities may well invalidate the idea behind shifting drive to the rear.....powersliding!

 

[Haz]

I've not seem the set up so just guess work for me atm. Would thinner oil give the effect that it's spinning faster so could result in a more 50/50 split? But then it could struggle to transfer the power to the front as well if the rears end up spinning?

 

[DaveL485]

Thicker fluid would be more drive to the rear when both wheels have grip, but neither front or rear should spin while one set of wheels has grip.

 

[Haz]

so more to equal drive and 4 wheel spin/drift only . . . nice! chop chop with the testing, oh and some vids too

 

[DaveL485]

Like this?

[video=youtube;EmaALRHbeZ0]http://www.youtube.com/watch?v=EmaALRHbeZ0&feature=player_detailpage#t=26s[/video]

Or this?

[video=youtube;v7RF7X2RXoE]http://www.youtube.com/watch?v=v7RF7X2RXoE[/video]

Or this!

[video=youtube;SxOBmuYyOwI]http://www.youtube.com/watch?v=SxOBmuYyOwI[/video]

Maybe this

[video=youtube;LsqBHH9lvLs]http://www.youtube.com/watch?v=LsqBHH9lvLs[/video]

But NOT this...

[video=youtube;ZtS6OnonaO4]http://www.youtube.com/watch?v=ZtS6OnonaO4[/video]

"How not to use a brake bias adjuster in the wet" lol!

 

[Haz]

lol, most vids make a good watch, the donut one looks like it makes you go dizzy but spins well on the spot. i ment some of how yours handles if it works the way you think after a fettle