Thread: Climbing dunes in a D4 - engine cutting revs

Originally Posted by BobD

I recently did the hard track up Big Red and found the D4 flew over the top (backing off a lot at the top to slow it down) in either 3 or 4 low range with no run up at the bottom .... I will try to post a video some time if can work out how!

Please do Bob, I'd like to see it. Will be out there late July.

Scott

Originally Posted by LandyAndy

How hard were you pressing the loud pedal???? 100%????
In Gordons course he says the DSC will still work when under full throttle/load.If you havent got the handbook,order a copy from his website.Some very good info there,its basically the course notes.
Im with the others,low range,unless its hardpacked sand and you are travelling a long way.
Andrew

No, hard pedal was not 100%.

Gordon's book suggests that revs should be maintained around 3500rpm to keep momentum. So was pretty close to that.

So 2 key questions for clarity if Gordon or others more informed can answer...
1) would revs dropping to 1k be a sign of DSC kicking in even when DSC is switched off; and
2) does sand mode operate differently between high and low range?

How were you keeping the revs at 3500? If you were in drive in high range you would have to have hard accelerator, which will activate traction control and reduce power. Even if you put it in first high range and hold it there manually rather than low range fourth you will have much less accellerator pedal. As soon as you use too much right foot in the D4 on sand it cuts power, whether we like it or not.


Read the FAQ at the top of the forum and Gordon's book to find out how low range changes lots of settings in the car to make it work better off road. Others have posted previously how there D4's would not go up long sand hills like their old Patrols and Toyotas but putting it in low range fixed it.


I was experimenting in sand dunes at Albany over Christmas after I could not get up a soft sand hill that my son's D1 TDI 300 auto just walked over, even in low range. Like you, it would power up and suddenly lose power as I increased throttle openings to maintain speed in auto mode. I thought about what I would do in my Patrol and realised I woud be in third low range in my 6.5 Chev powered vehicle. I tried that in the D4 and it just walked over as easily as any old Toyota, D1 or Nissan. I've since done it on many sand hills in WA and also Big Red with the same results. You cannot have lots of loud pedal on sand hills.

Great info Bob.
Thinking about it,our last fishing outing at Horrocks,I made a track for myself at our fishing spot by driving back and forward so I could get out later.Aaron didnt even get close to where I was,I rekon he was in hi-range.He ended up spitting the dummy and walking to where we were fishing.
I hope these GOE wheels and Cooper AT3's peform better than the OEM tyres.
Andrew

Andy,


The few times I have been stuck in very soft sand I've had my tyre pressures too high. Each time I just lowered the tyre pressure to around 18, put it in Rock Crawl mode and drove straight out. I always carry Max Trax but I can't remember needing them on the D4. Used them a couple of times for the Patrol. The 285 x 18 inch tyres make sand better but I didn't have a problem with the OEM tyres, even in very soft sand at Muchea at road pressures, where the Patrol would struggle on 33's at 18 psi.

On the day we were using 15psi and strugling,it was very soft and deep sand.Aaron did have to deploy the max tracks once that weekend,they work really well with the D4s electronics.
Andrew

I had a very similar problem in the high country over the weekend. I'd hit a really steep rough section in high range and the car would suddenly pause, almost like it's gearing down. It's always at the worst time when you needed momentum to crest a hill or something. Low range never behaves like that.

It seems special programs + high range doesn't like low speed steep inclines.

Originally Posted by LandyAndy

On the day we were using 15psi and strugling,it was very soft and deep sand.Aaron did have to deploy the max tracks once that weekend,they work really well with the D4s electronics.
Andrew

Did you use one pair of Maxtrax Andy? I was hoping I'd get away with just the one pair I bought if needed.... Fits nicely tied up against the back of the cargo barrier. .. Seems most people use 2 pairs though?