Outer Limits 4x4 Board

Running some 38 x 12.5 x 15 TSLs on beadlocked rims what is the best presure to run them at there on a GQ wagon aired down to 15 for a quick run way to hard

I know you said 38 TSL Swampers......... BUT 34X11.5X16 JT2s on beadlocked 7inch rims on 80 Series Cruiser work ace with 10PSI in all rock, mud, hill situations. I drive cafeful enough for them to stay at that pressure all day. They would go lower if I wanted more traction but would have to blow'm up after the obsticle.......back to your question..it will depend on the sidewall strength and amount of flex. Keep lowering till you see them really flex around/over rocks and other obsticles, then drive accordinally the rest of the time. The lower the better!!!!

yeah wat Jonesy said 10lb in front depending on weight in rear 8-9lb

oh hang on , some grammer !!

yeah , wat Jonesy said !!
10lb in front !
& depending on weight in rear , 8-9lb !

moose wrote:yeah wat Jonesy said 10lb in front depending on weight in rear 8-9lb

oh hang on , some grammer !!

yeah , wat Jonesy said !!
10lb in front !
& depending on weight in rear , 8-9lb !

Moose, more sleep, less coffee

IMHO it depends on the mud ....if you are after "floatation, then you I'd be thinking about 10PSI, but if you want to cut through a crusty top layer or need extra diff centre clearance then I'd run more pressure.....

I know this isn't what people do in practice, but I've always had this feeling that you're better off keeping your tyres hard for mud, for the reason Wooders said - cut-through. I dunno about everyone else's car but mine doesn't "float" on mud even when it's got low tyre pressures!

Lowering tyre pressure makes much more sense to me when you're on rock or hard dirt because it allows the tread to spread over more of the surface. In mud, your whole tyre is in contact with the mud whether your tyres are hard or soft.

Interestingly, I talked to this old bloke that had been driving earth moving equipment (and 4WDs) for forty years and he basically said, "never run those mud tyres under 50psi." That's not what you hear from the young 'uns, but it's enough to make me think about experimenting with it.

What I think you should do is experiment with different pressures and satisfy yourself as to what works best.

Anything to do with cars is full of old wives' tales that don't always make sense so you have to test it out for yourself, imho.

Jason

If ya lower ya pressure in the mud your tyres seem to clean themselves

much betta when ya get on da gas , think how the tyre is flat at the bottom full with mud and as the tyres spins the tread stands back up cleaning the tyre ......thats wot i found anyways

Ps yes i no my explanation suck but i cant think how to explain it

some1 else may have sum betta wording

yep i've found in many cases where when i've been stuck im a muddy gully that 10psi or lower will help heeps. so it should also apply for mud unless you are getting stuck coz of diff clearance. then you'd want more pressure to give you that bit of extra height.

I find with a tall skinny mud tyre that more pressure works especially when combined with a sloppy layer of mud on a firm ground. Wider tyres tend to work better with a bit less air and the floatation principle. just experiment, you've got beadlocks so you aren't running a huge risk if you go too low.

grimbo wrote:I find with a tall skinny mud tyre that more pressure works especially when combined with a sloppy layer of mud on a firm ground. Wider tyres tend to work better with a bit less air and the floatation principle. just experiment, you've got beadlocks so you aren't running a huge risk if you go too low.

I second this motion

I have run 750X16 Dunlops over some of the muddiest tracks around here and I have also run 38.5 TSLs over the said same tracks using grimbo's tyre pressure description. I dont have beadlocks but run Simmex tubes and I can get down to 8lb with no adverse effects.

The 750X16's with say 35lb tend to cut through the sloopy mud and find the firmer ground underneath, this is how they get their traction... they also clear of mud easily because there isnt the width in the tyre to become clogged up.

The wide TSLs with a low pressure ( say 10lb) use "suction" for the traction, by covering a large area they get their grip..... they clear themselves well at low pressure because the mud is "squeezed" tightly at the contact patch yet the tread opens up and releses the mud as the wheel is rotated off of the contact patch.

experiment experiment experiment ....... its the only way to really know for yourself !

Kingy

I run 38 TSLs and when I go off road I run around 5-6psi. I mainly do rock, but if there happens to be mud I do it at 5-6psi

I did the BIG boghole at Menai a while back at 6psi and made it through............JUST I wasn't willing to air up to 20psi and have another crack at it

I don't like mud so I spend as little time as possible in it

BTW a neat tip I saw if you are expecting to encounter mud.....
spray the tyres with cooking spray before you leave home..... the lugs will quickly disolve the sprayed but onroad, and the voids keep the pray to greatly assist in clearing

Wooders wrote:BTW a neat tip I saw if you are expecting to encounter mud.....
spray the tyres with cooking spray before you leave home..... the lugs will quickly disolve the sprayed but onroad, and the voids keep the pray to greatly assist in clearing

huh, you weren't sniffing the cooking spray whilst typing this were you.

I used to use the cooking spray on the body work if i knew it was going to be a muddy day makes it way easier to clean afterwards.

grimbo wrote:

Wooders wrote:BTW a neat tip I saw if you are expecting to encounter mud.....
spray the tyres with cooking spray before you leave home..... the lugs will quickly disolve the sprayed but onroad, and the voids keep the pray to greatly assist in clearing

huh, you weren't sniffing the cooking spray whilst typing this were you.

I used to use the cooking spray on the body work if i knew it was going to be a muddy day makes it way easier to clean afterwards.

That might explain the headspin
Oh yeah also good for spraying through the radiator to prevent clogging & assist cleaning

chimpboy wrote:Interestingly, I talked to this old bloke that had been driving earth moving equipment (and 4WDs) for forty years and he basically said, "never run those mud tyres under 50psi." That's not what you hear from the young 'uns, but it's enough to make me think about experimenting with it.

I'm pretty sure my BFG MTs say not to inflate over 40psi. Personally I drop them to about 16psi, makes the ride that much smoother...at 50psi on gravel roads I reckon fillings I don't even have would rattle out of my teeth!

pressure really relates to your trucks weight...
i'm guessing that your wagon would be the same as my heavy GU ute.
i run about 8 psi but because your CV's aren't as strong as mine i would start at 12 or if its slippery enough go down to 10.

JMTUG













Just My Totally Uneducated Guess

Thanks guys i used to run my centapeeds down at 10 they worked fine .The question related to driving up a extremely steep long flat slimy hill were when you stop most of the time you will slip back about 2to3 meters .On the weekend i made it up at15 psi but the hill stopped me 3 times i had to back up a small amount and start again were as my wife in her jeep with my old centapeeds on they are 35 x 10,5s had them spinning and made it in one run thought airing down to 10 might help as going from 30 to 15 didnt seem to change the tyre at all it just didnt bag out

What pressure would people recomend on a hilux with 37" MTRs running internal beadlocks?
Is it ok (or worth it) to go lower than around 8psi?
At really low pressures will the sidewalls get too hot and damaged if Im doing a bit of faster stuff not just crawling.

At the moment with my 33" MTRs, no beadlocks they run happily at 10.
Paul.

ausyota wrote:What pressure would people recomend on a hilux with 37" MTRs running internal beadlocks?
Is it ok (or worth it) to go lower than around 8psi?
At really low pressures will the sidewalls get too hot and damaged if Im doing a bit of faster stuff not just crawling.

At the moment with my 33" MTRs, no beadlocks they run happily at 10.
Paul.

It it worth it or ok yes it can be. We have guys in the Suzuki club that run at 2psi on 36" Swampers and it works awesomely but it puts alot of strain on steering etc. If you are running this low you shouldn't be doing the faster stuff as it will potentially cause damage in the long run. Again just experiment, as long as you take it slow and have an air source try a variety of pressures and see what happens. Alot of times dropping just one more psi can have a huge effect