Tyre pressure

[Canaussie]

Hey all, was at Byfields NP this weekend and it was awesome, first trip in the Disco off road. Well I have a lot to learn still.

If anyone has been there you know the hill ya have climd to get to the beach at Nine Mile. First run with TR in sand mode almost made it the top the ran out of momentum had DSC off tyres at 25 psi to start. Well all the way back down to the bottom to try again. Switched settings to mud ruts because that is what the track was like only with sand. Still no go. Tried in auto and in manual. Well I lowered the pressure down to 20 psi still no luck. Somehow along the way the vehicle lowered to normal height and was wondering why I was dragging. A few attempts and still no luck. Well our friend recommended going to 16 psi...which I was bait reluctant but gave it a go. Well up and over I went finally after an hour of trying. I was happy to get up and over unassitsted. Well the Pirelli scorpion zeros are not an ideal tyre for sand...lol.

Left the tyres at 16psi for the rest of the day without incident also being a careful when cornering. I am going to invest in 17" tyres and rims to have as a spare set.

We had a blast and I know now what the Disco is capable of.

One wired thing that was happening was the vehicle would stall sometimes at the top of a few attempts...don't know why. Also with the depth of the ruts the spare was dragging.

1 the heat shields seam to not help can these be removed.
2 would new rods be beneficial instead of llams
3 can you get steel rims for Discos....

Had a blast and can't wait to go again!


Cheers

Billy[QUOTE]

[Pete1]

Billy ,
Were you in low range , done heaps up there in old county V8 and 4BD1 diesel and a Disco 300 TDI never used low range once never a problem getting off any of the beaches , and it was bone dry !

Pete.

[~Rich~]

1 the heat shields seam to not help can these be removed.
2 would new rods be beneficial instead of llams
3 can you get steel rims for Discos....

Cheers

Billy


Yes
Yes, if that suits you.
Yes - Dynamic, do a search for them.

Last time on Stockton beach I dropped down to 14psi without an issue, went great anywhere. ( no i don't drive across sideslopes!)

[Canaussie]

Billy ,
Were you in low range , done heaps up there in old county V8 and 4BD1 diesel and a Disco 300 TDI never used low range once never a problem getting off any of the beaches , and it was bone dry !

Pete.

I'm still very inexperienced in 4x4. Tried to get up the hill ya know the first long one to get up into the scrub......did it in high eventually, tried low going through the gears to keep momentum. It was really chewed up and very deep ruts but still made it in the end. Was good to be with mates in case I ran into trouble. Of course they payed out on me but had a great time.:D

[Canaussie]

Yes
Yes, if that suits you.
Yes - Dynamic, do a search for them.

Last time on Stockton beach I dropped down to 14psi without an issue, went great anywhere. ( no i don't drive across sideslopes!)


Thanks Rich I'll search. I origanally thought the heat shields where steel but no just plastic.:p

[Pete1]

I have not taken the D4 up there and it is the first auto transmission I have had in a 4x4. My first attempt would be to get into 2nd high and hold it in that gear and try and hold revs at around the 2000 mark or a bit under. Depending of course on how rough the going is. Be careful dropping your tyre pressures below 20psi. Might be ok just on the beach but when you get on the tracks and crossing tree roots they could break the bead.

Pete

[DiscoWeb]

Billy,

The single biggest change to sand performance is tyre pressure, 14 -16 psi is fine in sand provided you do not corner to hard and try and roll one of the rim.

Also and particularly in sand you must check you have the DSC off as it kills momentum.!!!

Obviously you need to be careful if the track is not 100% sand and having never driven in Byfield I do not know the conditions but as Rich said as Stockton very low pressures can be maintained all day with little or no risk to tyres.

I posted a thread some months back seeking feed back on preferred pressures for 18 in rims for everything other than sand driving which might give you some additional feedback.

George.

[Canaussie]

Billy,

The single biggest change to sand performance is tyre pressure, 14 -16 psi is fine in sand provided you do not corner to hard and try and roll one of the rim.

Also and particularly in sand you must check you have the DSC off as it kills momentum.!!!

Obviously you need to be careful if the track is not 100% sand and having never driven in Byfield I do not know the conditions but as Rich said as Stockton very low pressures can be maintained all day with little or no risk to tyres.

I posted a thread some months back seeking feed back on preferred pressures for 18 in rims for everything other than sand driving which might give you some additional feedback.

George.

Ya I know 16 psi is not the ideal pressure but this track is steep and soft and the ruts were very deep. I did try and keep it in second but maintained higher rpms. Going up was very bouncy and I was worried I would be changing tire out for spare. In the end I didn't need a tow. Felt a bit dissaponted at first that the disco just didn't kill it but tyre pressure seems to be the real go there. I do need to get more lift for tracks such as that one so llams or rods may be the go.

I also have a huge list of stuff I want to get.....wife is going to kill me....glad I work in the mines....lol

1 Arb delux bar
2 winch undecided on brand
3 spotlights
4 roof rack
5 awning
6 UHF
7 compressor Arb ckma most likely
8 dual battery kit traxxide
9 llams or rods
10 fridge
11 tyres and 17" rims bb6 look nice

On top of this I still want a camper trailer going to be an expensive year:twisted:

[discotwinturbo]

Billy,

Also and particularly in sand you must check you have the DSC off as it kills momentum.!!!

George.

On the big dunes in the south west of WA, even with DSC off, it still crept in and cut engine power at the worst possible time. Only way I could get over was 14 psi (which did not work in high range), dsc off, sand mode, and low range while leaving in drive.....then it sailed over. Did not cut engine power. I will never get caught out again on these steep long dunes.

Brett.....

[Canaussie]

On the big dunes in the south west of WA, even with DSC off, it still crept in and cut engine power at the worst possible time. Only way I could get over was 14 psi (which did not work in high range), dsc off, sand mode, and low range while leaving in drive.....then it sailed over. Did not cut engine power. I will never get caught out again on these steep long dunes.

Brett.....

What's the deal with the engine cutting power, mine did this and I was confused as to why......it also stalled a few times as well at the end of a few attempts. I'm I doing something wrong?

[GJP]

The trick to driving in soft sand is how you set your tires up, you need to increase your footprint length. By reducing tire pressure and to maximize the footprint length you need to have tires with plenty of sidewall height, larger rims and small sidewall height is the reverse as to what you are trying to achieve.
Tire pressures are variable to the conditions and somewhat experimental just a another PSI lower can have a remarkable difference, you soon learn to identify sand conditions and what PSI would be best to suit those conditions. In some instances 12PSI was required to negotiate some beaches up Lancelin way.
However you must always take a compressor to make sure your tires are bitumen ready for the trip home, otherwise you might have a disaster.

[101RRS]

What's the deal with the engine cutting power, mine did this and I was confused as to why......it also stalled a few times as well at the end of a few attempts. I'm I doing something wrong?

Most likely DSC was back on - when you switch it off, it does not stay off. With each change of TR (and maybe other functions such as changing from hi-lo or height change), DSC comes on again - in my experience limits revs to about 2700rpm and causes issues with TC activation as a result as well.

Garry

[~Rich~]

Dead right there Garry, an easy trap to fall into.

Pity we cannot select an Auto off option, yes I understand why they won't!
Every time I restart the car in the Simpson I've got to press that button :twisted:

[discotwinturbo]

Most likely DSC was back on - when you switch it off, it does not stay off. With each change of TR (and maybe other functions such as changing from hi-lo or height change), DSC comes on again - in my experience limits revs to about 2700rpm and causes issues with TC activation as a result as well.

Garry

Nope....dsc was definitely off. I kept checking to make sure......

Gordon told me that it still lurks behind, and will still activate when it thinks I am being too silly.

Every time it lost power, would drop back to first then power on again, then into second then lose power....and it just kept doing that. Dsc off the whole time. But in low, this was not an issue.

Dealer also advised me that you cannot completely turn dsc off.

Brett....

[Canaussie]

Nope....dsc was definitely off. I kept checking to make sure......

Gordon told me that it still lurks behind, and will still activate when it thinks I am being too silly.

Every time it lost power, would drop back to first then power on again, then into second then lose power....and it just kept doing that. Dsc off the whole time. But in low, this was not an issue.

Dealer also advised me that you cannot completely turn dsc off.

Brett....

Dealer advised me of this to you can turn it off but still works if it senses an impending disaster.......a bit conservative though.....lol

Still enjoyed Byfields again and can't wait to go back

Billy

[101RRS]

Nope....dsc was definitely off. I kept checking to make sure......



Sorry - my comment was to the original poster as indicated in the quote. I wasn't commenting on your issues.

Garry

[DiscoWeb]

Nope....dsc was definitely off. I kept checking to make sure......

Every time it lost power, would drop back to first then power on again, then into second then lose power....and it just kept doing that. Dsc off the whole time. But in low, this was not an issue.

Brett....

Brett,

Perhaps, and this is just speculation and theory the DSC is has a higher tolerance in low range even when off.

Perhaps they were smart enough to know that in Low Range you really need to put the DSC to sleep.

In high range even with it off the computer could still think you inadvertently turn off the DSC and as such has a low threshold before it kicks back in.

I am sure someone will have a better understanding than me who can comment but the above assumption is logical assuming you were doing about the same speed and therefore have the same lateral forces in low range and high range going up the dunes and the DSC did not activate.

Geroge

[discotwinturbo]

Sorry - my comment was to the original poster as indicated in the quote. I wasn't commenting on your issues.

Garry

No probs.....be nice to turn it off fully when one needs to.

Brett....

[discotwinturbo]

Discoweb

"Perhaps they were smart enough to know that in Low Range you really need to put the DSC to sleep"

Maybe. Gordon should know.

Brett....

[101RRS]

No probs.....be nice to turn it off fully when one needs to.

Brett....

I completely agree - absolute nonsense that you have to keep on switching it off.

Garry

[gghaggis]

The DSC system is never completely disabled. All you are doing is changing the sensitivity. When left "on", the system is more sensitive at higher speeds. Sensitivity is decreased when the car detects triggering of the cross-axle valves, which is normal in Low Range, but can also (rarely) be triggered in High Range.

When switched "off", sensitivity is at a minimum, but it will still trigger if full throttle and any yawing is detected. You are less likely to use full throttle in Low Range, so less likely to trigger it.

Cheers,

Gordon

[101RRS]

The more and more I learn about the systems in these cars the more disillusioned I become - OFF should mean OFF - and stay OFF until selected otherwise.

Garry