Going fast on rough roads
- Thread starter mistermeeseeks
- Start date
I mean, everyone has already said it, but I'll add in for airing down - every time I try and run a trail at full pressure, I get pissed off 1/2 way through and air down - it makes such a huge difference.
I also disconnect the swaybar, and I'm running RS5000x's on 31" M/T Legend EXP's. I used to run with SxS's and keeping up with them on the ride back to camp was always a challenge. for small bumps and stuff the faster you go, the smoother it is (to a point) This is cause the tire absorbs more of the bump and the suspension doesn't have to (or so I have been told)
if you don't have bump stops, get some - I don't, and any time I G out on the street or the trail, its a very unpleasant experience.
I also disconnect the swaybar, and I'm running RS5000x's on 31" M/T Legend EXP's. I used to run with SxS's and keeping up with them on the ride back to camp was always a challenge. for small bumps and stuff the faster you go, the smoother it is (to a point) This is cause the tire absorbs more of the bump and the suspension doesn't have to (or so I have been told)
if you don't have bump stops, get some - I don't, and any time I G out on the street or the trail, its a very unpleasant experience.
When my wife smashed her JK into my TJ it bent the front frame horns on the JK and pushed the sway bar into the springs. After waiting around for four hours while Liberty Mutual fucked us hard by falling to get us a tow truck I pulled the sway bar off the JK and we drove it five hours home on two lane twisty roads. It was not pleasant. We lived.
-Mac
-Mac
OP
So I went out to my spot this weekend. I aired down my tires and disconnected the front sway bar and man did it make a huge difference. I was going 30 mph down these dirt roads and it was great. Thanks for the advice everyone! That anti rock kit looks really attractive, I may see one in the future. Thanks again guys!
I had a similar experience; when I first got my LJ I was so excited to hit the mountain roads but I had to go so sloooowwww to keep the ride tolerable. I knew something was wrong when a 90's Ford Ranger passed me.
I later learned the things mentioned in this thread and was very satisfied with airing down (~15psi) and getting the JKS quick-disconnects.
Once or twice I've accidentally forgotten to reconnect the sway bar and driven ~80 miles on the interstate; there were no problems with instability or excessive body roll.
15 psi seems to work on the highway just fine, if you don't have time to air up.
you don't necessarily need hard-wired on-board air to air down/up; a nice compact compressor that connects directly to the battery will do.
I air down to 15 psi or so when I am driving rough roads. I leave it at that pressure when I go back on pavement unless I am going a long distance. Is there any harm done by doing this other than making the gas mileage worse? It doesn’t seem to have affected tread wear.
OP
Thanks for saying that. At the end of my trip it started raining so I drove a little bit till I was out of the rain to reconnect the sway bar. Everything was fine, but I was concerned if there was any danger going fast with the sway bars not connected. Now I know it's no big deal.
If you run at speed with less air pressure than the minimum required to support the load yes you will damage the sidewalls as they flex and get hot. The damage is cumulative over time and could lead to sudden failure. Air up when you hit the pavement. Also look up the load and inflation tables for your tires and see what the minimum pressure is for your weight.
DaveydTJ
New Member
Nope, Just slower in the corners as you will have a lot of body roll. Recommend making one change at a time. Air down first, disconnect second, change shocks, if necessary, because $$$. Also, are you running C load tires? This is essential for a good ride.
LONGJP2
TJ Expert
Cheaper shocks like the Ranchos don't dissipate heat well generated by rapid, large range movement in fast driving on rough roads. That decreases their ability to cushion or even causes them to quick working all together. if you are addicted to fast driving on bad road, reservoir shocks might work f you but not your wallet.
I did that for a while, it kind of created a weird feeling in the body roll where the body would move a bit and then after the slack in the clevis room was taken up, it would catch. Dont recommend it, plus you have to zip-tie the sway bar up out of the way and the stock links don't swing around 180* to its REALLY awkward. It's a fine temporary solution, but not a great long term.
BFG does not specify minimum pressure is for weight for my tires. It only says 80 PSI max for 3417 lbs max weight. My weight is about 4500 lbs, so if this is linear (which I am quite sure it is not) then the minimum pressure would be 26 psi. I run at 10 psi less than that and the tires do not seem to get hot at all. Maybe I’ll start checking them with an infared sensor.
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I struggle with it too. It makes sense that having the bar transmit a bump to the other side so you get it on both sides instead of just one would be rough, but IFS vehicles have to have a much thicker bar due to roll center issues yet they still ride smoother than an SFA so it doesn't seem to be as big of a contributor as people think.
I disconnect my swayloc because it takes a few seconds, but for the impact on a rough road I can never convince myself whether it's real or placebo.
I've found that load and inflation tables between different manufacturers are consistent with tire size. Toyo seems to provide the most information out there although I have tables for Firestone and Michelin. Here is Toyo https://www.toyotires.com/media/pxcjubjs/application_of_load_inflation_tables_20200723.pdf
but even they do not go below 25 PSI, but you can look at the data for your size and get an idea. TJs are pretty light so more forgiving on low pressures for sure.
35s at 8psi, Black Max shocks, and a Sway Loc engaged or disengaged and hammer down. Low speed is significantly harsher ride quality than opening the throttle.