Outer Limits 4x4 Board

Just scratching around. I may not build a buggy, but I wouldn’t mind knowing more about your proposed 600kg buggy. Now that you can’t build it for Werock I hoping you will spill the beans?

I don't know that it's going ahead, quite a simple idea. But we'll leave that to mock.

sierrajim wrote::lol:

I don't know that it's going ahead, quite a simple idea. But we'll leave that to mock.

Yeah that's why I'm hoping he will tell me what his plan's were

just for reference i weighed mine today with me in it
and full of fuel

it was 1320kg
im 70kg
id say while competing it would be around 1300kg

redzook wrote:just for reference i weighed mine today with me in it
and full of fuel

it was 1320kg
im 70kg
id say while competing it would be around 1300kg

70!!!!!

I'm 100 +

DeWsE wrote:

redzook wrote:just for reference i weighed mine today with me in it
and full of fuel

it was 1320kg
im 70kg
id say while competing it would be around 1300kg

70!!!!!

I'm 100 +

and that is tech how?

redzook wrote:

DeWsE wrote:

redzook wrote:just for reference i weighed mine today with me in it
and full of fuel

it was 1320kg
im 70kg
id say while competing it would be around 1300kg

70!!!!!

I'm 100 +

and that is tech how?

Just considering the extra weight I would have to count for in a design. it makes a huge difference.

I wanted to build it with an alloy K6a frontwheel drive auto, fitted N/S beside the driver, single seat ofcorse.
Run the front wheel drive diff, into a pair of narrow track zook diffs, air shocks, susspension hmmm not saying , alloy wheels, lots of alloy, kevlar and speedholes.

Mock

ljxtreem wrote:I wanted to build it with an alloy K6a frontwheel drive auto, fitted N/S beside the driver, single seat ofcorse.
Run the front wheel drive diff, into a pair of narrow track zook diffs, air shocks, susspension hmmm not saying , alloy wheels, lots of alloy, kevlar and speedholes.

Mock

MQ diffs and buckshot will get you to 1000kg

Just out of curiosity mock what tyres were you planning on running on them weakarse zuke diffs

Me thinks it would have settled the current debate one way or another.

37's
If the car only weighed 600kg,
then the zook diffs would be plenty strong


Mock

May be already looked at, but have you considered the driveshaft rotation direction going to F/R diff, and which side that leaves the engine? This will influence which side you end up having to steer the thing from, and therefore the availability of appropriate knuckles and steering boxes.

Most FWD setups place the motor forward of the diff, meaning that with the Zooks offset diffs you could end up with the engine smack-bang in the middle of the buggy, or driving the diffs from the opposite frame rails.

Best engine/tranny combo would leave the engine on the right hand rail with diff centerd on the drive line of the Zooks diffs and you in the LHS seat. This would mean the engine in "native FWD" would need to have the engine in the RHS (normal drivers side) to operate correctly.

Only real probs I could see is that there would be no lockable center diff (unless you welded it), and no ready source of LHD bits (knuckle and steering box.

Or just turn the diff centres upside down and get more clearance under the driveshafts.

thought about all this,
all depends wich way around u put the engine
will be driver to the left and engine will be pasenger

no steering box etc, cuz full hydrolic

all cool

just got too build it


Mock

Gwagensteve wrote:Or just turn the diff centres upside down and get more clearance under the driveshafts.

Wouldn't that starve the pinions of oil?? With the sort of pinion forces involved in rock crawling, I would have thought that wouln't have been the wisest approach

Build it LHD so that everyone knows how hardcore you are importing a buggy from the states.

Then you can tell 'em the front diff is an incredibly rare narrow track closed knuckle dana 44 and way stronger than their NSW hilux s%*t.

aiiii!

Ahh its like spua or spoa all over again.

Aiiiiiiiiiiii!!!!!

yeah, the Datto 44

Mock

Okay This is one thing that I completely don’t understand. I was looking at having the motor and box mounted on the left hand side. Then flip the diffs upside down to line up with the drive shafts. Obviously then the steering knuckles would be facing the wrong way. Would I then need to cut these of the dif and change them side to side to be on top. Or is sierrajim saying you can flip the gears inside the diff and have the motor on the right hand side.

Refer to pick to demonstrate what I was thinking

If u keep the motor on the right hand side, U can keep the diffs as stock,
By tuning the engine 180 on the spot u can change wich way the outputts spin.
Dosnt matter wich way the engine is facing, its only going to change the outputs position left to right, a few inch's, but the engine is still on the right, so drive line angles should be still sweet

sweet


Mock

Gary, I'm not so sure that the oiling issue is much of an issue in a pure comp buggy.

the front will be getting at least as much oil as stock as the rotation of the crownwheel will be pushing oil up the drain.

The rear might more of an issue, but I don't think that the stages will be long enough to get much heat into the bearings, and the wacky angles will see plenty of oil slopping around the housing.

It would always be an option to overfill the diff a bit to make sure the pinion bearings were wet, but for a werock type crawler, I really think it will be sweet.

I believe that pinion failure on sierra diffs is mostly due to to tighta#&$ reusing the crush sleeve when replacing the pinion bearings, which allows a bit of slop to develop so the pinion thusts back and forth and eventually kills the lot.

At least one diff specialist is able to replace the crush sleeve with a solid spacer and shims to avoid the problem of the crush sleeve collapsing under high load.

Steve.

sorry you've probly considered this but, arn't you looking at a max of about 50:1 reduction? is that going to be enough to run 37's as slow as you'll need?

Matt

approx 3.0:1 auto first into around 4.8:1 (possibly as high as 5.2:1 depending on car) transaxle diff ratio x 4.6:1 mq ratio = 66:1 before you add the effect of the converter.

Many US rock buggies are running as tall as 36:1, but most seem to sit in the 55-75:1 area with autos.

I think that for general recreational use, more reduction might be worthwhile, but comps are a different kettle of fish.

In terms of drivability, it is an advantage to load up a converter as the converter becomes much more progressive when it working against load.

With more than about 80:1, an auto becomes very undrivable as you cannot stop it in gear adn the converter will not respond well to changes in load so much of the traction advantage you get with an suto is lost too.

Also, the plan is for as light a car as possible and less weight allows less gearing.

Gwagensteve wrote:The rear might more of an issue, but I don't think that the stages will be long enough to get much heat into the bearings, and the wacky angles will see plenty of oil slopping around the housing.

It wasnt the bearings themselves I was concerned with, but the actual pinion/ring gear contact area. It will be "high and dry" in the rear when ascending whilst taking the bulk of the load. Unless you filled it to the brim you would not get sufficient oil to the contact area from splash alone, given the standstill timeframe possible, and generally slow rotational speeds involved.

Metal on metal under high load doesn't sound too nice

I believe some have actually welded tabs onto the ring gear to drag oil further up onto the pinion. Only problem would be if you shaved the diff you may not have clearance.

As Steve said the WEROCK runs are not too long. I drove my Zook (MQ diffs) from the rock garden in Gembrook all the way back to Gembrook itself (8 or so KM) with almost no oil in the diff after punching a hole in the rear cover plate.