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  View original topic: Staun 2 Deflator review and tire inflation suggestions
Jon_slider Fri Jun 13, 2014 9:43 pm

Staun 2 Deflators
http://www.amazon.com/gp/aw/d/B00C9MLMLI/ref=mp_s_...SX200_QL40

The Staun 2 deflator has a pressure range from 10 PSI to 50 psi using the included red spring set.

I calibrated mine today so that I can set my tires (rated 3042 lbs @ 80 psi) to my personal street pressure of 32 front, 40 rear, and my Offroad pressure of 20 front, 24 rear. My 87 Syncro westy front axle weight is 2300 lbs, rear axle is 2700 lbs. I am inflated to ~30% higher than actual front axle and ~38% higher than actual rear axle weight.



Besides having a wider pressure range than original Staun Deflators, the Staun 2 can be tightened with a wrench so they can't be uncalibrated by mistake.

Like the originals, the Staun 2 can be triggered manually when the target pressure is too close for automatic triggering. This makes Staun superior to other brands such as Oasis Trailhead Deflators, which won't trigger if there is less than 8 psi difference.

I like the features of Staun 2 better than original Staun, or Oasis Trailhead Deflators.

If you dont already have an airpump, here is one I recommend, Viair 90P
http://www.amazon.com/Viair-93-VIAIR-Portable-Comp...ords=viair


or the next step up, Viair 300P
http://www.amazon.com/Viair-30033-VIAIR-Portable-C...ords=viair


Tire inflation suggestions:

Here are some suggested street pressure inflations for various tires. This is ~based on VW recommended tires and inflations discussed in great detail here, http://www.roadhaus.com/tires/guideline.html

This table shows the recommended inflations for OEM tires
http://www.roadhaus.com/tires/OE%20Tire%20Load%20Inflation%20Table.html

and this PDF lists load tables for current tires
http://toyotires.com/sites/default/files/page-files/LoadInflation_Table_P-LT_102913.pdf

This is where I go to look up tire load, inflation, and size specs for most tires.
http://www.tirerack.com/
Unfortunately that info is not available for Nokian, it requires reading the sidewall of an actual tire.

suggested syncro street pressure inflations (offroad use 60% (3/5ths) of street pressure, for sand use 33% (1/3 rd) of street pressure)
Stock inflation spec for OEM 185R14, rated 1710 lbs @ 55 psi, 43 front, 48 rear
BFG AT Ko 195x75x14, rated for 1710 lbs @ 65 psi, 51 front, 57 rear

the following inflations target 1500lb load front, 1750lb load rear. GVWR for syncro is 5512 lbs.
BFG At Ko 215x75x15 and 215x70x16, rated 1765 lbs @ 50 psi, 41 front, 50 rear
BFG AT Ko 225x75x16 rated 2680 lbs @ 80 psi, 35 front, 44 rear
BFG AT Ko 245x75x16 rated 3042 lbs @ 80 psi, 31 front, 36 rear

suggested 2wd street pressure inflations. GVWR for 2wd is 5160 lbs.
Stock inflation spec for OEM 185R14, rated 1710 lbs @ 55 psi, 43 front, 53 rear
BFG AT Ko 195x75x14, rated for 1710 lbs @ 65 psi, 51 front, 63 rear
Nokian WRC Van 205x65x15 rated 1874 lbs @ 55 psi, 39front, 48 rear
Nokian WRC Van 205x70x15 rated 2094 lbs @ 65 psi, 40front, 48 rear
BFG At Ko 215x75x15 and 215x70x16, rated 1765 lbs @ 50 psi, 40 front, 50 rear

Note that VW load inflations exceed GVWR by about 24% and they do not distinguish westy from tin top.

If you want to inflate to more closely match your actual vehicle weight, I suggest you weigh your vehicle, each axle separately. This can be done at a truck scale or a local dump. Once you know your actual axle weights, loaded the way you normally drive, I suggest you inflate to 24% above actual weight, as a safety margin.

Note that under no circumstances did VW ever recommend using the same pressure in the rear as in the front. They use approximately 20% more pressure in the rear than in the front. imho, using lower pressure in front than rear, makes for safer handling in curves and in crosswinds.

If you have specific questions about your tire and van, feel free to send me a PM.

fwiw, actual vehicle weights vary widely:
http://www.roadhaus.com/tires/load.html
"1) This data is the result of "Actual Vehicle" weigh survey's taken on various VW Van Lists
 
Results:
 
- 33 Vehicles Total
- 62% were loaded to within 10% of capacity or more
- 24% were loaded over the spec limits
 
-Weight distribution shows 67% of vehicles have more weight on front axle than the rear axle."

How to do a 5 tire rotation:
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=43
"insert the spare in the right rear position at every rotation. Place the [left front] tire... as the spare until the next tire rotation."



About tire pressure difference front and rear:
Note that the silver sticker in the door jamb of a Vanagon Syncro (and also 2wd), lists different tire pressure for front and rear. imo it is NOT correct to use same tire pressure front and rear.


Why different front and rear pressure? Besides the fact that VW recommends it:

1. the front weighs less (until otherwise verified by actual weighing each axle on a truck scale)

2. Understeer is safe.

Understeer is created by having less pressure on the front. For example, if you are in a turn, and you accelerate, the van wants to go wide on the turn, this is understeer.

Similarly, when coming off throttle in a turn, the van wants to tighten the arc. This is a safe configuration, and allows you to set a line in a curve, and make fine adjustments by throttle steering.

Oversteer is the opposite, and I find it scary. In that scenario, with equal front and rear pressure, I find I am making many more steering adjustments in a turn, and if I want to widen the arc I have to reduce throttle, and to tighten the arc, I have to speed up. Totally counterintuitive, and imo, unsafe.

For example, with Oversteer, as the speed increases, the turn tightens, which increases body roll to the outside of the turn.

and a crosscheck option

use a tape measure, on smooth level ground measure from the center of the wheel to the ground. The goal is for all 4 corners to be the same height. And for the sidewall bulge to be the same.

If its hard to know the center, pick a spot on your wheel that is a repeatable reference point, such as the bottom edge of a center cap..

You can also count tread blocks in contact with the ground for a good approximation.

for example, if you find the front tires only have 2 tread blocks touching, (I use a credit card and try to slip it under the tread block) and the rear has 3 blocks touching, then the front could be aired down a bit.. (or the rear psi increased, but never above max spec on the sidewall)

Jon_slider Thu Jan 19, 2017 2:26 pm

Load table, updated link
https://toyotires-1524598101.netdna-ssl.com/media/...151020.pdf








iliketowalk Thu Jan 19, 2017 8:45 pm

That's a ton of info. Nice!

Getting 4 deflators and then calibrating them all differently seems a bit goofy though. I see what you're getting at, but why not do 2 and 2 (front and back aired down pressure)? Are you really using them when you air back up? (Air up, then air back down to street pressure?)

I would instead recommend the ARB deflator (with gauge), you can set each tire wherever you want and it deflates super fast...

Jon_slider Thu Jan 19, 2017 9:04 pm

iliketowalk wrote: ARB deflator
Also a great option. The ARB does not have auto shutoff.

The Staun2 deflator turns off automatically at the pressure that I preset them to. So in the time I walk around the car, installing one in the front and one in the rear, I can pretty much pull the front one and move it over, to the other front, and similar for the back.

Yes I also use the Staun2 to set my street pressure easily. I can overshoot while pumping up, and then use the Staun2 to drop them to my target.

I also put a pair of Staun2 in my daughters Jetta, so she can easily get her tire pressures matched side to side, also with a different front and rear.. (and different than my Van)

davevickery Fri Jan 20, 2017 9:58 am

I bought a set of chinese made knocks on ebay for around $10 and I really like them. Mine are all set to the same ~22 psi (it takes some trial and error get them set). Normally I just go around the van putting them on and by the time I get back to the first tire, it is time to remove them, again in the same order. I don't wait for them to stop. They relaease the the same amount of air out of each tire and I basically take about 15 psi out of each tire in the time it takes to put them on and take them off. The whole point of these things is not having to sit there by the tire while it is deflating. The ARB deflator may be faster on a single tire, but doing all 4 tires hands free has got to be faster overall.

I wasn't willing to pay $80+ for the Stauns although I imagine they are better than the $10 ones. I use these all the time now. If they don't last, I would consider upgrading but I am happy after a year and maybe a dozen uses. They took a while to get set to consistent pressure. And one adjustment collar came loose at some point and the pressure changed, so next time I reset them, I will probably use locktight. But otherwise no issues.

https://www.google.com/search?q=ebay+brass+tire+de...p;tbm=shop

hans j Fri Jan 20, 2017 10:10 am

I have the Trailhead Deflators. All set around 22 psi. I had a pair to the co-pilot and I do the drivers side. I check my maps and get the GPS recorder ready and by the time that's all done, the tires are done.

http://www.trailheaddeflators.com/product.htm

Jon_slider Fri Jan 20, 2017 11:14 am

davevickery wrote: I bought a set of chinese made knocks on ebay for around $10 and I really like them.
Im definitely jealous of the price, and have no doubt they work fine. The range on those is 6-30psi. To keep them from being unadjusted by mistake, use pliers to tighten the lock ring.

The original idea with Staun was that they could be changed to a different pressure on the trail, by counting how many turns the adjuster is rotated, which changes pressure by 3 psi per turn. But when lending these to someone, they always twist the head to remove from the tire, and this changes the adjustment. Hence the need to overtighten to prevent unadjusting.

Trailhead deflators are great too, some have a range of 5-40psi. They cannot be unadjusted by mistake as it takes an allen wrench to set the pressure. I consider this a more practical way to adjust. The only reason I did not choose them, is because their max is below the max I need for street pressure.

the Staun2 have a range of 3-50psi, and have facets that fit a wrench to lock them tight. A 215x75x15 BFG has a max psi of 50, so with the staun2 I can set any street, dirt, or sand pressure.



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