Tire pressure in the dunes.

onanysunday

onanysunday

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So after the crash I don't know if there's  been a good old-fashioned tire pressure thread. I had my Can-Am out a few weeks ago and ran 8 psi in the bighorns. Thing is plush. Of course that is probably more suspension than anything. On the buggy I have always run 6.5 in the Baja pros in the fronts and 15 on the sport tire of America rears. How low could I lower the tires on the buggy and still be okay being on beadlocks? When the sand gets rough like this it beats the crap out of you and I'm just wondering how much difference lower air pressure is going to make. Especially as big as the ruts get in the corners. I don't want to knock a tire off the inside of the bead either. Plus my little V6 and power band if I go too low in the rears it will probably suck all my power up. Curious what everybody is doing. Especially buggies. :dunerdude:

 
I am running 15lbs in the rear and 5lbs in the front on the same car and tires that you have.  I have gone as low as 12lbs in the rear, but for error of safety with the 2d, I am more comfy at 15lbs.

 
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I have 10.75 up front and run 10psi and have the big Dune Sports out back and run 12psi. I would like to go lower in back but the sidewall flex rubs the springs. I think you could go lower in the back for sure and more bite might be fun

 
Cookie said:
I am running 15lbs in the rear and 5lbs in the front on the same car and tires that you have.  I have gone as low as 12lbs in the rear, but for error of safety with the 2d, I am more comfy at 15lbs.
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Yours is a subie be correct? For me with the V6 turbo and s4 I have a crap ton more weight back there. If it has worked for you for sure I will try 5 in the front.

 
onanysunday said:
Yours is a subie be correct? For me with the V6 turbo and s4 I have a crap ton more weight back there. If it has worked for you for sure I will try 5 in the front.
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Honda 3.5 turbo, we should be similar in weight

 
8 in front on Baja Pro and 12 in rear - I'll run 15 - 18 in rear when wet as I'm worried about trans.  Funco 6 cyl Subi.  Never gone below 8 lbs in front but would if I thought it would cut the chatter on bad days!

 
Front airbags I run 40 and rear bags 45. I think I could get away with lowering the front bags two or three PSI and maybe lower the car and inch or so. Not sure if that would make any difference in the ride or not. I've always aired them up to 40 to keep that nose up higher so it doesn't dip into the sand. Maybe worth trying as well.

 
Sounds like the consensus is 12 PSI in the rears would be okay and worth trying. When I welded all of the pieces to put the micro stubs and 934s in the rear I made the car a little wider. So there is plenty of room between the tire and the trailing arm.

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I used to be the in low pressure better floatation more cushion camp, but after learning that having squishy tires not only takes away from your shocks doing their job but (since the tires are compressing and your shocks are not as much as they would normally) also lowers total ground clearance and can cause you to bottom out when you wouldn't normally, while 3-4" may not seem like much it makes a world of difference on my yxz specifically but ymmv.

 
I never run my buggy paddles less than 10 psi to hard on sidewalls if sand is wet 15 to 18 to help out the tranny fronts I run 8 to 10

 
I believe there are only to reasons to run lower tire pressure.

More Traction

Pros - More bite, Cons - more potential damage

Better Ride

Pros - A little better ride in small chop, Cons - Your not letting your suspension do its job, also still more potential damage 

 
I continually run 20 psi in the rears. I throw my big dual sport car around and let it slide like crazy. Sounds like I’m the only one that runs them that high. I like it though. 

 
You can run 8 if you want. 

The problem is handling balance trends towards the end with less air for the weight. Eventually, wheelspin and cornering balance will suffer and either you wheelie everywhere or suffer grinding understeer. 

 
I run about 18-20 in the rears, and 9 in the front. 36 blasters w/ 12.5 fronts. I like to slide. Still has plenty of traction. 

 
There used to be a great thread in this. Normal HP (400-ish or less) likes lower pressure in paddles (10-15), high HP, big cars bends the peddles back at throttle, lays the tires flat open-ish. So big HP requires higher pressure on the paddles. I run 12 in the front on both my cars, 15 in the back on 400hp turbo Honda (to save on de-bead cuz I always let friends drive that car, should be 12) and 18 on 650hp big, wheelie machine car. Lower pressure in the big car makes no difference in wheelie grunt, higher pressure gives it lift on flats, 3-4 gear when nailing it. 

 
3000 lb car.  440hp to the ground.

35" Bajas in the front, 8psi

33" Blasters in the rear, 16psi

 
I have 10.5's Razor Blaster up front & 33x15 #1 cut Sand Blaster in the rear.

I run 10Lbs up front all of the time.  I have tried as low as 5 and as high as 15 and it does not seem to make much of a difference in how the car drives.  FWIW, I think the wheel is too narrow.  I would like to get a 6" wheel & see how the tire works.

I have been running 10Lbs in the rear & with as uber soft as the sand has been this season that seems to work pretty well.  every trip I start out @ 15 & end up going down to 10 the first day.  if the sand is wet I go up to 20.  I wish I had got the taller paddle so I could keep the pressures a bit higher & get the bite Im after, but its fine.  I also think I need a wider wheel on the rear.  it just seems to narrow for this paddle. 

 
Did a fast 25 mile ride along the gecko ridges and up around Osborne this morning. Of course everything is now completely tore up with lots of cross hatches and moguls. I went down to five in the front and 12 in the rear. Also dropped the front airbags about 5 PSI. It was a noticeable difference. Still a rough ride but more tolerable. I also was focusing on using the dead pedal to push myself back in the seat more than normal. After 17 years I think I might get an expert involved and have some work done on these shocks. The other thought is do I consider going to 3 in front and rear. Pricey option but considering the amount I use this car maybe worth it. A new Funco would be nice but not in the budget.

 
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