Offroad Driving Tips

The MY11 manual has a center viscous limited slip diff. The MY11 auto (excluding the S-edition) has an electronically-controlled, multi-plate transfer clutch system which actively manages power distribution based on acceleration, deceleration, and available traction. This active torque split system distributes power 60/40 front/rear under normal conditions, but balances power 50/50 when slippage is detected.
 
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Torque split in AT & MT AWD Subarus

Gidday All

Owing to the amount of misinformation around here and elsewhere about this subject (to which I have also contributed ... ), I have put the link to the Subaru/FHI web page that Thunder found into a new sticky under the Transmission & Drivetrain sub-forum here:

https://www.offroadsubarus.com/showthread.php?t=4110

Hope this solves the misinformation problem.
 
Diagonal spin and blowing diffs

Watched a mate lift diagonally through ruts during a climb in hard pack.

His 35" tyres bit in at full noise and about 1kph and blew the **** out of the front diff, a cool $3000 repair.

It is tempting to put the boot in when two wheels lift especially if you have a VLSD because it feels the extra difference in rpm gives you a little more push.
The problem is when the tyres come back to earth tho vs can go bang.

One technique is to ride the clutch while you have diagonal spin to the point just before where it slips.
This gives you a much more economical "weakest link" to absorb the shock when your wheels bite.

Hope I've explained that clearly and this can save someone an expensive repair bill or from being stuck out back.

Vehicle in this case was a D22 Navara
 
This is a good, informative thread that is worth resurrecting though I will only do so by way of some general ramblings to start off the new year rather than the tight, bullet-point posts above.

One thing this thread reveals is the mess that Subaru AWD models have been over the past 20 years. Unfortunately, all that experimentation has resulted in the current standardization around Active AWD with VDC. Albeit a capable system, much better than earlier versions, it is not the best that Subaru has had. But it is plenty good enough in bad weather on pavement, which is what Subarus are really made for.

Watching BlueFox's well-known San Juan mnts videos, I have long noted the completely different way in which an open differentials, no-DR, no VDC MT Foz is driven vs. my AT VDC/VTD machine. Where he has to bump the car continuously into rocks and over ruts, I can just power over them at minimum speed, as diagonal spin is a momentary event for me (for the first 1-2 sec before VDC stops the offending wheels). While no substitute for true lockers, wheel-braking ABS has been plenty good enough for the kind of ruts and rocks my clearances allow me to handle. Lifting a rear wheel on a serious climb would likely be a bad scenario that has not yet materialized. The fairly stable R:F split provided by the VTD has been handy, making for smooth climbs of long mountain passes and hills with an overall gradient of 20-30 over anywhere between 0.5 and 2 miles and with spots of 50 to 60 % per HillFinder.com (and per my bottom; the engine did momentarily lose voice on two of those, but speeds were low range style).

I have done my toughest climbs at 28-30 psi though the last time around I drove at 24 psi. I have not done sand of more than a few inches deep but I have done well in that kind of sand at street pressures (34-36). The B9 using the same AWD system saw a lot of miles in anywhere between 2 and 8 inches of mud on street tires and pressures though the first time I took it out of the desert it did get stuck like a brick in 3 inches of snow (with the traction control on, LOL). I am not sure about the above comments regarding sidewalls. Really low pressures make them extremely vulnerable to cuts, even by sticks. Using the sidewalls for traction off large boulders is hardly a Subaru game. Hence, I do not see the reason to air down under low 20s except for deep sand, mud or snow.

Generally, my 5 EAT VTD/VDC car takes good care of the traction side of the equation leaving the clearance side to worry about. The awful approach angle is almost impossible to remedy without major mods and diagonal crossing/climbing only goes that far making the moving of stones around necessary even in fairly ridiculous situations. No wonder that all the "damage" sustained after a great year out there has been on the underside of the front bumper cover (not counting minor brush marks on pax side). The skid plates also show some traces of use after going over the crest of a steep hill too fast and, separately, falling into a rut at the very last 20 yards of the more difficult first 50 miles of a 100 mile unpaved road: LOL, what a classic (I had stopped to take a pic of the steeper, upper portion of the switchback and totally missed to take a good look at the easy, lower portion, which had eroded since summer).

Here in the US a Wrangler Rubicon, the best off-roader in the US at present, can be purchased for the same money as my OB (2dr, a bit more if 4dr). But I do not want to put up with semi-military hardware on daily basis. Thus my only real complaint is the lack of optional adjustable suspension and a bit more aggressive front end to start with (Foz style, plus a temporary 2.5 in lift would be all I personally need). That, plus factory option AT tires, full size spare, proper car battery and recovery points would have made my OB into a moderate off-roader superior to much costlier machines both on and off-road. With the Toyota retreat from the segment, the Nissan existence at the lowest level only, and the ridiculousness of Rover prices and reliability, Subaru could easily get a lot more of the moderate 4wd crowd. Alas, the only enthusiasts for which Subaru cares are the WRX crowd...

In the absence of adjustable suspension, bridging devices would be great. So far, I have used rocks and carried firewood bundles (it is a foolproof solution: carrying them means no need to use them, not carrying them means building rocks, etc). I cannot imagine anyway that I can find room to carry any bridging devices given how packed the car is on the way from home to base-camp. Firewood bundles are cheap and can be purchased everywhere.

So that is that as far as my Subaru is concerned: great comfort to and from trail, great traction, great power even w/o dual range, almost livable lowest and rocker panel clearances after mild mods, but a really bad approach angle necessitating creative driving, wheel-lifting, and rock-building where a 2wd truck can just power through. Got to admire the low center of gravity and not excessive wheelbase and footprint on narrow shelf roads with steep drop offs, though. I know people do it all the time but I have never had a truck and I cannot imagine driving some of what I have done in one (I have seen rocks colored by the paint of trucks whose drivers must have chosen damaged pride over risking a fall of hundreds of feet).
 
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By the way, one more thing that has changed is the introduction of gas override function that kills the throttle upon brake application, which in theory is a major setback for us. It seems to me that at crawl speeds my AT car still allows a bit of simultaneous two feet operation, but thankfully I have not had to test this in practice.
 
Gidday MAS

Sounds as if you are fairly similar to me in your driving wants/needs/habits.

One reason I got a Forester to replace my ageing '93 Impreza was the far superior approach, hang and departure angles. These were better than my Impreza even on the SF Foz, but far better on my SG series II. The Liberty (Legacy in the rest of the world) and Outback both suffer from a similar approach/hang/departure angle problem faced by my Impreza. Subaru have overcome this a little by making the Outback higher and higher, but the problem still remains.

The lesson to be learned is never let marketers, stylists or accountants design one's product!

The approach angle on both our SH and SG is around 24°. I measured this using a flat, heavy steel bar, line of sight (!) from the leading edge of the tyre footprint to the front bottom centre of the front bumper, using an application for my cell phone (Keuwl Spirit Level). Supported the middle of the bar using a brick ... . I know that this is supposed to be from the centre line of the front axle (hub), but it is too humid and my head hurts too much to do this properly ...

The SH looks to be less, because it has a longer nose, but it's also an 1" or so higher ground clearance than my SG.

Like you, I also have no desire to push my vehicle to its limits, having discovered about 40+ years ago how little time Mother Nature has for those who push the limits ...

My SG does everything I want or need it to do. I have fitted an aluminium sump guard. It could probably do with a 1" lift in the rear to complement the variable rate struts and springs I had installed when the SLS shat themselves. Such a lift would still leave the rear just within the OEM min/max height range by about 1-2 mms.
 
Gidday MAS

Sounds as if you are fairly similar to me in your driving wants/needs/habits.

One reason I got a Forester to replace my ageing '93 Impreza was the far superior approach, hang and departure angles. These were better than my Impreza even on the SF Foz, but far better on my SG series II. The Liberty (Legacy in the rest of the world) and Outback both suffer from a similar approach/hang/departure angle problem faced by my Impreza. Subaru have overcome this a little by making the Outback higher and higher, but the problem still remains.

The lesson to be learned is never let marketers, stylists or accountants design one's product!

The approach angle on both our SH and SG is around 24°. I measured this using a flat, heavy steel bar, line of sight (!) from the leading edge of the tyre footprint to the front bottom centre of the front bumper, using an application for my cell phone (Keuwl Spirit Level). Supported the middle of the bar using a brick ... . I know that this is supposed to be from the centre line of the front axle (hub), but it is too humid and my head hurts too much to do this properly ...

The SH looks to be less, because it has a longer nose, but it's also an 1" or so higher ground clearance than my SG.

Like you, I also have no desire to push my vehicle to its limits, having discovered about 40+ years ago how little time Mother Nature has for those who push the limits ...

My SG does everything I want or need it to do. I have fitted an aluminium sump guard. It could probably do with a 1" lift in the rear to complement the variable rate struts and springs I had installed when the SLS shat themselves. Such a lift would still leave the rear just within the OEM min/max height range by about 1-2 mms.

Yeah, the Outback is a victim of confused marketing identity. Within Subaru's lineup of Swiss-knives, the OB is the ultimate Swiss-knife.

Had I known that we would have ended with another Tribeca, I would have probably purchased a new FXT instead. But the OB is the minimum size we need to fit all our camping gear, the long-distance and rough road comfort is exceptional, and the FXT would have ruled out any popup trailer in the future.

So, I do not know. I wish I had an FXT in town and on trail. I prefer my H6 OB in between!:ebiggrin:
 
I don't know what sort of camper trailer you think an FXT would struggle with, but my N/A 2.5 L drags my CT around pretty much everywhere without getting even slightly asthmatic. I must admit that I haven't tried it on anything really wild (yet ... ), but it isn't my intention to do anything like this with my CT on behind anyway. It is my intention to park the CT at some convenient camping spot and branch out from there - i. e. not planning to do the Old Telegraph Track to Cape York with it ... :iconwink:. I have had the pleasure of taking it both ways along Halifax "Road". I posted about this in the trip reports sub-forum. It handled that with consummate ease.

Because of the higher torque at low revs, the N/A is more suited to this sort of thing than the XT, particularly when one has any kind of DR box. Unfortunately for those in North America, Subaru decided that you didn't need this! What did I say before about marketers, stylist and bloody accountants? And that's from a retired CPA ...
 
I think a reminder of the thread topic is in order here "Offroad Driving Tips".

When I get time I will sort it out a bit
 
Offroad Driving Tips ( Auto and Manual )

I just read the whole thread, twice. Thanks for all the great info.

My 2006 Outback Wagon with 6 cyl has a 5 speed auto with 45% front, 55% rear power split, and it has rear LSD. No Traction Control (aka throttle reduction on wheel spin). No VDC (aka same axle ABS, aka electronic LSD?).

I have 245x55x17 All season tires. My street pressure, front, is 35psi cold, it rises to 38psi in actual use on a sunny day. I use -2psi in the rear, with just 50 pounds of gear in the cargo bay.

Its my first automatic in 40 years.

for my model:
1. Do you recommend Driving Through the Foot brake downhill, (left foot braking)?

2. Do you agree it is NOT a good idea to Drive Through the Hand brake (poor man's rear LSD)?

3. Same question UPhill, do you recommend Driving Through the Foot brake or Driving Through the Hand brake?

Im confused which model it is OK, or irrelevant, to use "driving through the foot brake or driving through the parking brake"

4. Do you recommend pulling out a fuse for ABS when driving on the beach?

5. For my low profile tire, what pressure do you suggest on dirt with ruts and rocks (guessing 30?), and what pressure on deep dry sand? (guessing 15?)
 
1. Driving through the brakes when going downhill: I can't think of any benefit of doing this. Just select 1st gear and brake as needed.

2. Driving through the handbrake when going downhill: As above.

3. Despite what many people will tell you, driving through the brakes to prevent wheelspin when going uphill (or through otherwise challenging terrain) offers no benefit unless your vehicle has 'torsen' limited slip differentials. It's true that vehicles (such as newer VDC-equipped Subarus) with electronic traction control use the brakes (automatically) to control wheelspin, however the fundamental difference is that such systems can brake wheels individually - as a driver with a pedal, we cannot. Applying the footbrake will apply the brakes equally to the spinning and non-spinning wheels equally (aside from front-rear bias) leaving you with no net gain, and simply result in more load on your engine and transmission.

4. Disabling ABS (removing fuse) for beach driving: There is a case for this, as ABS will activate very readily when braking on sand, leaving you with very little braking power when you need it. Otherwise, just drive vigilantly, allowing plenty of stopping space.

5. On rocky and rutted tracks, regardless of pressure, be very wary of tree roots and rocks coming into contact with the sidewalls, as they are the weak compared to the tread. Reduced pressure will give you better traction if needed but be aware of the increased sidewall bulge this will result in. For deep sand, 15psi is the norm, going as low as 10psi if needed, but heed the the usual warnings (no sharp turns, low speed only, reinflate promptly when back on the road, etc).

Hope that helps!
 
Ihve got an:

Hi-jack.
Rope (3x 9 mtr.
Tire repair kit.
Small tire compressor.
6 D-shackles.
Little saw.
An axe.
An shovel.
4 1.5 ltr Bottles water.
Oil and cooling fluid.

Eric
 
In water, the most critical thing is to get out and determine how deep it is and what the surface underneath is. Grabbing a stick to use as a dipstick works well- as does walking throught it. Having a snorkel can be advantagous- as long as it is a sealed syetem. The last thing you want is it letting in water and/or falling off, but let's not go there! Maintaining momentum is critical, not too fast water goes everywhere but not too slow you get stuck. Joining up with experienced people will be a real benefit.

Just a few words of warning on walking through water.
-Never attempt to enter fast flowing water in the vehicle or on foot unless it is obviously very shallow.
- Don't enter the water on foot in areas where crocs, stingers or stonefish are likely to be present.
- Don't walk though muddy water in bare feet. It's not unknown for muddy puddles to contain broken beer bottles, sundry car parts, old televisions etc.
- The safest way to gauge the depth of a water crossing is to let someone else drive through it first.
 
Proper 4wd ...depends on how you drive it.
No 4wd would help you if you will drive itopen diffs you coupd get stuck on simple diagonal where most smart awd systems would pass... So it depends on everything. You coulf easily embarase yourself with your old 4wd car against some cheap dacia duster 1.3
 
Scalman nailed it - it’s about how you drive it! Independently sprung vehicles require a different mentality when off-roading and picking a line.

In the Murray Sunset there are plenty of tracks that a stock 2wd could get through easily if it hasn’t rained. It’s quite disappointing for such a “large and remote” area of Victoria…

Cheers

Bennie
 
Weight just means so much in off roading...most people forget that when they starting "modify" their proper 4wd cars...they just making them less capable and more dangerous...then they think hmmm i need more power ..and then its never ending story..." But i need that fridge and those wooden boxes in my trunk..." No you dont.
 
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