None of this would have been thought of if it weren't for project Super Low.

 

What are some tough and beefy AWD vehicles?

Cadillac SUV with 6.0 - Borg Warner 4481
old Syclone/Typhoon - Borg Warner 4472
Tri Star Cars - wrong design

 

Based on the above layout, if I go AWD what would the torque split need to be? I'm gonna say 65% rear and 35% front. Most AWD transfer cases are pretty close to that, but in my setup, the driveshaft normally going to the front (35%) is actually going to the rear. So I'd get too much bias to the front. I wonder of that would be a problem or not?

If I were only going RWD I could just weld up the transfer case diff and sent all the power to one driveshaft. As it is, I may have to look for a 50/50 diff.

 

i would shoot for a more reasonable goal for total height. bc u will still be the lowest fbody and u will still look way wicked. im diggin the lambo style. make any progress at all on the project?

 

[QUOTE=JasonWW;10677891]No 4WD, AWD. Big difference. [QUOTE]

whats the difference?? lol

one means all the wheels are being driven, the other means all the wheels are being driven...! lol

Chris.

sorry think i know where you are coming from. you want to switch to RWD.

 

[QUOTE=chuntington101;10684180][QUOTE=JasonWW;10677891]No 4WD, AWD. Big difference. No, see post 187.

The main difference is that a 4WD transfer case has no differential built in. That means it can't be used on the road. It would scrub the tires badly wearing them out and make the vehicle difficult to steer. When you corner all 4 wheels are traveling at different speeds. If your in the mud the wheels can slip easy enough to not be a problem.

I'm looking at an full time AWD system and have no use for a locked center diff or any gear reduction. The 2 most common diffs are the clutch type and viscous coupling type. I'm going to assume most here are familiar with the preloaded clutch disc style. The viscous coupling style has both shafts turning plates with holes in them. The plates are in a sealed housing which are then filled with a thick "liquid like" syrup. Normally this goo makes both shafts turn at the same speed. When one side loses traction and it's shafts starts to spin faster than the other shaft, the goo gets warmer and thickens up forcing both shafts to spin together. It's actually quite simple, reliable and lasts a long time, but the one down side is that it takes a second to activate.

In my opinion, I think a clutch setup in the rear and center diff with a viscous type in the front diff would work pretty well for me. Both rear wheels will always get power. Power will always be going to one of the front wheels as well. If I lose grip, the weaker front wheel will spin for a second and then both fronts will grab.

It's not perfect, but it's the best I can come up with that uses no fancy electronics and won't cause a sudden shift in cornering traction. If I ran clutches front and rear with a VC center, it could cause a sudden oversteer to understeer situation in corners which would be quite a handlfull.

I still don't understand how the engineers can bias the torque towards one axle. How's that possible?

So I think I need to look for a clutch type AWD transfer case with a 60/40 F/R split. You'd think a pickup truck would be like that since they have a lighter rear, but no. They are roughly 60/40 as well.

See why I want to keep things simple? For RWD any strong transfer case will do. I can just remove or cut out everything not needed. All I really need is the input shaft and to connect it solid to the front driveshaft output. Then it will be lighter as well as full time 1:1 to my rear wheels. Very simple.

One thing to note is that a lot of newer transfer cases are now cast from magnesium. That adds a small wrinkle to things.

 

Then you do that. good luck to you.

 

Jason, i call it one thing you call it the other mate!

the vicus stuff is good. esp is you can get one with an elctronic controle like the scoobies and Evos have. The new Evos have increadably fast reacting system that controle the presure in the center and rear diffs. its pretty impressive stuff and straight out the WRC cars. they run all three diffs as visucs and constantly adjust the traction to each wheel to maximise both drive and cornering ability.

having said that i bet you are looking at over $50K for a WRC drivetrain (minus gearbox)! lol.

Chris.

 

That's not good. That's bad. Those electronic controls work with the ECM and BCM to control all those functions. I need practical advice, not rocket science stuff. BTW, I don't think the ones your talking about are viscous. They don't use pumps. Maybe their using Haldex diffs.

I'd need to stick to the older, non-electronic parts. What I'm looking into are the old BW 4472 AWD transfer cases most famously known on the Syclone and Typhoon trucks. They are a chain drive and much smaller than the typical 2 speed units, but have held up to 8 second qtr mile passes. So they must be pretty stout.

 

The Borg Warner 4472 transfer case is a 2-piece aluminum case, chain driven, viscous clutch type transfer case. This produces a system in which all wheel drive is engaged all of the time. Torque is transmitted through a planetary gear set which distributes torque at a ratio of 1/3 front and 2/3 rear.

Here's some pics.

 

What about a vette drive train and just remove the torque tube...would that work?

 

Already been answered. Much too long. Maybe?

You can go to mongoosems.com and see their corvette GTP replica or any other GTP replica and see for yourself. It seems they only use the C5 Auto Trans.
Even though it's a nice neat package, I'd have to stretch the rear half of the body just to keep the rear wheels under it.

Even as tough as the 4472 TC is, it may not hold up to manual transmission abuse in a strickly RWD capacity. That chain will be transfering all the power when it was only designed for 1/3 the power. The newer 4481 is used behind the 6.2 Caddy SUV which weighs what, well over 5,000 lbs? I just can't find much info on it. I know it's big, but gutting it of all the extra parts should keep the weight down.

There's always the NP 205 as well. I don't want to go too exrtreme like a 5 ton military case, so I need a good compromise.

 

Remember this?
I've been studying the old Syclone drivetrain and it's the same basic concept. There is a short front axle with the diff and gears offset to one side. The axle goes through the oil pan. You can make pretty much make any vehicle AWD as long as you don't mind the engine being kind of high.

The reason I voted it down was because I need my engine low and you can't put the skinny axle through the crankshaft. I think some of you guys suggested I tilt the engine and put the axle under the trans. I didn't understand what you were saying at the time. Besides, I doubt I could tilt it enough without causing oiling problems. A couple of other ideas come to mind, though.

How about I do one better than the G50 trans as far as getting the axle close to the engine? I got this idea from the C5 rearend. Mount the engine so the T56 trans is pointing to the back of the car, ala GTM. Now what if I made a spacer between the engine and T56. Let's say 2" or 3" and then run the axle through the spacer either above or below the input shaft? Hell, there may already be room without a spacer. I need to get in there and look.

 

Here's a cool pic of a Syclone front axle which tucks tightly under the oil pan.



Here's the front axle from a newer Cadillac SXR. It goes through the pan.


Drag race setup in a mid engine Corvair. It has a 2 speed Powerglide trans.

 

I also put together some axle to engine pictures to let you guys see what's what. I did some at stock axle location, some with a slightly longer wheelbase and some with the long wheelbase.

This is what I think is the ideal engine position. If I can get the axle through the trans case I may be able to do the stock wheelbase.


Another stock wheelbase, but facing the other way. It would be tight, but that offset axle should clear.


If I move the rear wheels back a little it will clear just fine.


There's no way to go through here unless I tilt the engine way too much.


Here is the really long wheelbase. Plenty of room here. I wouldn't need an offset axle. I could mount the tough 8.8 IRS and a 2 peice driveshaft. I may be able to slide the engine back some as well to give more room.

 

Why not just use a ZF trans axle? isnt this the easyest way to go mid engine? i think in the long run it would be cheaper and stronger than trying to engineer a bunch of "cheaper" parts to do the same thing.

 

Now here's where the axle would end up if I turned the engine around. That might work if the transfer case doesnt stick out too far and I tilt the engine slightly. It might interfere with the shifter, though.



Here's about where the engine would be if I mated the trans to the C5 rear axle. The engine is too far forward.



When I move the engine back, notice how far back the centerline goes?


Now my pictures are pretty accurate, but obviously not exact. I'm goint to look into mating the C5 rear to the trans. It looks too long, but it may not be. Or else I can lengthen the car just enough to fit the tires under it. I noticed that Mongoose MS only does C5 Auto trans in their GTP replicas. Maybe becuse there's no way to shift the manual trans? I'll have to talk to them as well as get the total length to see if it will fit in the car or not. I prefer this over having to use a transfer case and all it's unknowns.

 

It's way out of my price range.

 

yea I saw you covered that on page 8 or 9. Sorry.

 

I found a really cool article here.

"V8-capable" transaxle sources
http://www.locostusa.com/forums/view...ec931f4398f782