SSM 47757: Harsh ride quality.

[jzweedyk]

As you air down your tires, the contact patch of the tire increases geometrically. So going from 32 to 28 psi doesn't do much. Contact patch is what keeps you from getting stuck. Think of it this way, if the tire was flat, look how much of it contacts the ground. There is a limit to how far you should go, which is decided by the tire range (C D on so on, C is a flexible sidewall) the size of the tire, bead lock or no bead lock wheel, and also the weight of the vehicle. A smoother ride is a side benefit of airing down. Since you are running a 17" whee with a 35" tire, there is a lot of sidewall to flex. As you air down it flexes easier so it will smooth out the bumps. Also airing down will help the tire to resist cutting on a sharp rock if you are rock crawling. If you are going off road you need to air down and need either a compressor or air tank. It is a small item compared to a 70K truck. The reason you need to air up for the pavement is because tires will overheat at pavement speeds if you don't, and then they will fail. You can't go too low off road or you will pop a bead off the wheel and the tire will go flat.

 

[Richard Hinsley]

Really that low?
Its a long highway drive back home and nowhere to air the tires back up. Unless buy a small compressor.

Yes air them down and listen to others who have been doing this for a while. Air pressure is vital offroad, I'd suggest getting a air compressor. Lower air pressure increase your tread footprint giving you better traction.

 

[IDontDoUrban]

...need either a compressor or air tank...

My neighbor just gave me a 5 gal, 125psi tank. What’s the secret formula to determining if it’s enough to take 4 tires from 20ish back to 40ish? Assuming the tank is no longer helpful when it gets down to 40psi, can I get 80 psi worth across 4 tires from the 5 gal?

Will appreciate any experience that anyone can share!

 

[Ricoman]

Really that low?
Its a long highway drive back home and nowhere to air the tires back up. Unless buy a small compressor.

After much reading on the Forum and research I also learned you need to air down when going on Sand and Off-Road....and found this Air Compressor (Viair 45043 Automatic) with high ratings and looks like its perfect...Ordered mine last month off Amazon...but it came from 4WD.com as the seller...so check both sites for deals...I'm seeing its down to $254 shipped which is even a little lower than I paid when on sale last month....
Have not used it yet,but its small/compact and very well built....IMHO

https://www.amazon.com/dp/B000X9EGFS/?tag=fordraptorforum-20

 

[jzweedyk]

My neighbor just gave me a 5 gal, 125psi tank. What’s the secret formula to determining if it’s enough to take 4 tires from 20ish back to 40ish? Assuming the tank is no longer helpful when it gets down to 40psi, can I get 80 psi worth across 4 tires from the 5 gal?

Will appreciate any experience that anyone can share!

I do not know the formula, but I am sure 5 gallons at 125 psi is not enough, by far. The real advantage of an air tank (like that one) is so your compressor can refill it as you move to the next tire. It is designed to be inline between the compressor and the fill line to your tires. You can get away with a cheaper compressor and turn it on to fill the tank before you are ready to fill the tires, and let it run as you fill the tires. The other side is a cheaper compressor will not last as long.

 

[IDontDoUrban]

I do not know the formula, but I am sure 5 gallons at 125 psi is not enough, by far. The real advantage of an air tank (like that one) is so your compressor can refill it as you move to the next tire. It is designed to be inline between the compressor and the fill line to your tires. You can get away with a cheaper compressor and turn it on to fill the tank before you are ready to fill the tires, and let it run as you fill the tires. The other side is a cheaper compressor will not last as long.

I was afraid of that. My neighbor used on his race team for fine tuning psi at the track when power wasn’t available. I have a good compressor, just nowhere to plug it in when coming out of the mountains.

 

[Booth9999]

My neighbor just gave me a 5 gal, 125psi tank. What’s the secret formula to determining if it’s enough to take 4 tires from 20ish back to 40ish? Assuming the tank is no longer helpful when it gets down to 40psi, can I get 80 psi worth across 4 tires from the 5 gal?

Will appreciate any experience that anyone can share!

Air will not be enough, you would need to fill it with CO2, then you would weight it full and as it goes down it will weigh less. It might take a tank full to see what the limit of the volume would be.

 

[7six2]

So, I bought this portable air pump:
https://www.amazon.com/dp/B07CN6N2GY/?tag=fordraptorforum-20

I know its not a Viair but after buying a Raptor my wallet isnt as fat anymore. Planning another beach fishing trip this weekend and I will drop the tires down lower than before.

 

[jzweedyk]

And like the other thread talks about, put it in 4 H and turn the traction control off. Big hill climb, lock the rear dif., and maybe put it into 4 L.

 

[7six2]

So I’ve been complaining about the stiff ride quality on my 2019 Raptor, and the advise that’s often given is to lower down my tire pressure. I am not doubting the benefits of doing such, especially for traction, but the question that continues to plague me is shouldn’t the much touted Live Valve system supposed to be constantly monitoring conditions and adjusting (in milliseconds)? Because it sure doesn’t seem to be doing anything special at all. It rides like a ¾ ton single cab truck on the road, in that I feel every road imperfection and stuff is rattling...until I hit a big bump then I can feel the benefit of bigger shocks. Off road seems to get bounced around a lot too, and never really “adjusts”. I hit a series of small dirt holes on the trail the other day and the truck started bouncing violently, straight up and down, and uncontrollably until I could bring it to a stop; exactly like what I’d expect from a “normal” truck....but not a Raptor with super fancy suspension. I find it hard to believe this is all because I didn’t let nearly all of the air out of my tires as has been suggested. I think I need to ride along with some other Raptor owners and see if its just me or if the truck needs to be looked at under warranty.