Tires...how low do you go and what do you use to re-inflate???? (1 Viewer)

[tls3601]

So I run 15X8 rims and 33X12.5X15 Goodyear Wrangler Duratracs on my '78 FJ40. As a noob I have been running 30 psi offroad and beating the ever living s"*it ou of my self on off road runs. My friend murf is running his '82 with 13-15psi offroad then re-inflating for pavement. What should I run off road...BTW my rims are NOT beadlocks. Thx!

 

[FF LC FREAK]

There are a LOT of variables that come into play here. The best answer is, what feels and works best for you. The tire's load range, the tire's sidewall stiffness, the weight of your vehicle, the terrain you are on, the issue of being able to air back up after a trail run before hitting the pavement, beadlocks, etc. If you have a way to air back up at the end of the day, it is easier to play around with to get the best PSI. If not, I wouldn't air down much below about 18 psi, because you will have a lot of sidewall roll once you get back onto pavement.

Personally, I run 35x12.50x15 Goodyear MTRs on non-beadlock wheels. If I'm running logging roads and I just want a little less harshness in the ride, I drop the pressure to about 18 psi. Rocks, I'll drop it down to about 12 psi. I could go lower, maybe down to 10, but I'm always worried about popping the bead without beadlocks. However, my MTR's seem quite a bit stiffer than the worn out KM's that I had before. I just did the Rubicon at 12 psi and didn't have a problem.

Finally, I have a VIAIR compressor and a 2.5 gallon tank for re-inflation. The tank does basically nothing for tire re-inflation and I wouldn't add it again. I think it actually hinders re-inflation, since it is trying to fill the tank and the tire at the same time. It is nice for my air lockers, though, since the compressor doesn't run nearly as much when turning on and off the lockers a bunch.

 

[Pin_Head]

You want to be able to go as low as possible without losing a bead. It all depends on your particular tire/rim combo, so unless someone responds that has the same combo, it is trial and error. 15 PSI would be a good place to start. I air my MTRs down to 10 PSI in the dunes at Pismo and have never spun a bead, but MTRs have notoriously tight beads. Airing up at Pismo is no problem as there are air stations out at the dunes and gas stations a few miles away.

 

[AKcruzr]

30psi is too high for the road, I run 20 on the road with 37 MTR's, and get even wear. 10# with non bead lock 15x8 wheels off road. I have a 20# CO2 tank with regulator set at 150psi for quick air up's.

 

[White Stripe]

I run 10 psi without bead locks. My sidewalls are pretty thick so they don't hold a bead too well at real low pressures. I have had it down to 6 but if its wet, the water gets into the bead and I loose pressure. I would say 8-10psi. I use a converted fj60 ac compressor that goes to a tank. It makes crazy amounts of air. I bring a full set of air tools if I am worried about breaking something and it pushes them pretty well. One of the best mods I made. After a trail run I hook up a blow gun and clean the interior out.

 

[1911]

33x10.5x15 BFG KM2 on stock wheels. 15-16 psi on dirt roads and 9-10 psi on rocks. Never lost a bead yet. Use a CO2 tank to air them back up.

 

[jim land]

35x13.50x15 bf krawler on 15x8 wagon and weld-on bead locks , no leak
street : 20 -25 psi
summer trail :12-16 psi
deep wet snow :5psi

air up with a belt driven York compressor ,(super fast)

 

[Fast Eddy]

I get almost 10% better mileage if I run 35psi vs 30psi on the freeway. It will take a lot of years to run into treadwear issues for me.

315-75/16s on 16x7 steel rims.

 

[SouthBostonFJ40]

To answer your second question, get a Superflow MV90. It's a great little compressor. This is the cheapest I've seen it advertised.

http://www.tooldiscounter.com/ItemD...&kw=SUPMV-90&gclid=CMX0-OHvv8cCFUeRHwod_9oMLQ

 

[tls3601]

Thx buds...really liking that Superflow MV90. Anyone know anything about Puma??

 

[tls3601]

All great replies, thx SO much, been killing myself getting beat up in the beast!!!!!!!!!!!!!!!!!!! SouthBoston I am going to check out the Superflow MV90. Anyone know anything about a Puma??

 

[Redgrrr]

There is a puma in the classifieds right now, I think jcordona has one listed

I run 6-8 in the back and 9-12 in the front so I can steer on 34x10.50x16 swampers on 80 wheels on my 40 I drive 20-30 miles after on the road.

Same psi on my 36x12.50x15 swampers on my other 40 with an 8" wheels

 

[SouthBostonFJ40]

I think the Puma is a lot bigger.

 

[65swb45]

CO2 tank with straight coupler ( no regulator) takes me from 15 (trail) to 22 (highway) in about 4 seconds a tire. Talk about instant gratification.

If you wheel long enough, you'll learn there is no 'hard' number. Pressure will depend on GVW, speed and terrain, and a seasoned wheeler will choose pressure like a golfer chooses a club, or a fisherman a lure.

Best

Mark

 

[upperblack]

I use a viair to inflate tires. A little pricey but well made and works great
http://www.amazon.com/Viair-40047-A...?ie=UTF8&qid=1440392353&sr=8-1&keywords=Viair
This is the one I own but they have less expensive models.

 

[DSRTRDR]

I have used an MV-50 for the longest time: ~$50-60

when I wheel with others who have a Puma, I try to find a mothercow

we have a Puma in our 80 (and will get one for the LX eventually), but it would take up much valuable space in a 40

 

[SouthBostonFJ40]

when I wheel with others who have a Puma, I try to find a mothercow

A mothercow...

 

[JohnVee]

My 40 has 33x10.5x15 KM2's on 15x7 rims. Trail pressure is usually either 12, 15 or 18, dependent on which trails I'm doing and weather. Lots of rocks out here.

The 80 has 295/75/16 Hankook MT's. It usually does the same trails around 13-15. Honestly, on both trucks, I just usually shoot for a pressure when airing down the first tire and make the others match. If I accidentally hit 12, I'm not gonna air up to 13 or 14.

My MV-50 compressor gets a workout and never fails. Very compact and comes with a case. I wish it had a better option than the screw-on chuck, but it's not so bad if you remember to make sure the valve stem threads are clean before installing it. Not being arthritic would help, too.

 

[Tools R Us]

All great replies, thx SO much, been killing myself getting beat up in the beast!!!!!!!!!!!!!!!!!!! SouthBoston I am going to check out the Superflow MV90.

The MV units are great, but in my experience would own two MV50s over one MV90. Running two, (one on each side) will net faster times, if one were to die, still could air up, cheaper, etc.

Anyone know anything about a Puma??

Great unit, maybe a bit big to fit in a '40, but more locals are fitting them in jeeps.

 

[Tools R Us]

CO2 tank ...

The fastest option, good if you don't wheel often. If you do, the refill run around/payment becomes painful.

I use a viair to inflate tires. A little pricey but well made and works great
http://www.amazon.com/Viair-40047-A...?ie=UTF8&qid=1440392353&sr=8-1&keywords=Viair
This is the one I own but they have less expensive models.

That unit likely come out of the same factory as the MV50. Has nicer accessories, likely slightly better wiring, don't know that it's significant for most. In air up races, performs the same as the MV50 and can buy three of them for less $$$.