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Topic Review (Newest First)
Yesterday 06:39 PM
65Chevy4x4 Back to what I was talking about. The antifreeze would ramp up pressure quicker to help with bottoming out.
Yesterday 01:20 PM
Java Played with air pressures this weekend.

Tires at 58.

Air bags at 70 which is just under 8" tall, its a bit better, BUT it does bottom out at this pressure.

At 60 its not any different feeling than 70 really. at 80 its harsher.

The Kelderman guys think I am feeling the rear end.... Maybe my expectations are just too much for this heavy of a truck?

09-21-2019 12:48 PM
Java Gonna put this one down as a win (so far!) a couple hundred miles and a couple passes and it's leak free! Going hose down the Underside with degreaser, I really hope this was the oil leak all along!

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09-19-2019 03:32 PM
Java
Quote:
Originally Posted by FirstRam View Post
The 1/4" restriction is only a pipe nipple long. Depending on the hose length, 3/8 will help but bigger is better. Just zip tie the tanks to your front bumper for a quick test.

The sad thing is that the shows I work on pay for everything and that gives us the opportunity to test on their dime. It really brings me down to earth when I need to place a McMaster order when I'm between jobs.
Thanks, the tanks had a 3/8 port so I just went with 3/8 line....

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09-19-2019 03:30 PM
FirstRam The 1/4" restriction is only a pipe nipple long. Depending on the hose length, 3/8 will help but bigger is better. Just zip tie the tanks to your front bumper for a quick test.

The sad thing is that the shows I work on pay for everything and that gives us the opportunity to test on their dime. It really brings me down to earth when I need to place a McMaster order when I'm between jobs.
09-19-2019 02:55 PM
Java
Quote:
Originally Posted by FirstRam View Post
The bigger the better! 3/8's is about all you can do without welding but you can still run much larger hose and tank fittings. If you get like the results, you're only a fitting away from having a free flowing setup. If you feel it isn't worth the additional effort you will be able to sell the unmolested bags.
Do you think 3/8 will flow enough to be noticeable I guess is my question. It will still have a 1/4" restriction at the bag connection. I just got 1/4x3/8 T's to make plumbing easy for the time being....
09-19-2019 02:27 PM
FirstRam The bigger the better! 3/8's is about all you can do without welding but you can still run much larger hose and tank fittings. If you get like the results, you're only a fitting away from having a free flowing setup. If you feel it isn't worth the additional effort you will be able to sell the unmolested bags.
09-19-2019 02:07 PM
Java
Quote:
Originally Posted by FirstRam View Post
I weld NPT 2" fittings to triple bellow bags to give us a fast dump option if needed, we use them to gimbal vehicles for filming. Use a hole saw and drill a 3/4" hole, grind the zinc off the top plate and tac tac tac a half coupling on there. Use a wet rag to cool it down between tacs/stitches. I usually TIG with Silicon Bronze for less heat input but MIG will be fine if you take your time.
Good to know! I need to learn tig at some point....

I already have the 3/8 fittings ordered. Think that will be way too small in your experience?

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09-19-2019 02:05 PM
FirstRam
Quote:
Originally Posted by Java View Post
Welding a second fitting in has been suggested. Not sure the bags would appreciate the heat, but may be a thought.
I weld NPT 2" fittings to triple bellow bags to give us a fast dump option if needed, we use them to gimbal vehicles for filming. Use a hole saw and drill a 3/4" hole, grind the zinc off the top plate and tac tac tac a half coupling on there. Use a wet rag to cool it down between tacs/stitches. I usually TIG with Silicon Bronze for less heat input but MIG will be fine if you take your time.
09-19-2019 10:34 AM
Java
Quote:
Originally Posted by GLTHFJ60 View Post
It will make a difference for sure. Would be interesting to data log the pressure in the bag vs pressure in the ping tank to see if there's any lag with a 3/8" line.
I'm sure there will be a lag. We will see soon what it does. Fittings are supposed to be delivered today. I have two 1 gallon tanks from dead compressors to figure out where to mount.

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09-19-2019 10:27 AM
GLTHFJ60 It will make a difference for sure. Would be interesting to data log the pressure in the bag vs pressure in the ping tank to see if there's any lag with a 3/8" line.
09-19-2019 07:55 AM
Java
Quote:
Originally Posted by GLTHFJ60 View Post
I think this is the best option. Increasing the effective volume of the bags is exactly what Java needs I think.



I'd expect you would want a BIG fitting between the bags and the ping tanks, to reduce restriction during high speed compression. As big as you can fit on the bag mounting brackets.
Yeah that's part of the issue too. The bags only have a 1/4" npt port.... I'm going to step it to 3/8 as close as I can. Hopefully that is enough line size. May not be, but worth a shot to start with. Welding a second fitting in has been suggested. Not sure the bags would appreciate the heat, but may be a thought.


EDIT: you can see the needled bounce on the gauge on bumps, its pretty fast acting, so I am hoping 3/8" makes enough difference.
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09-19-2019 07:52 AM
GLTHFJ60
Quote:
Originally Posted by FirstRam View Post
Reconsider ping tanks. I adapted a 1/2" push to connect to a coupling nut that fit the threads of the hollow mounting stud (3/4-16). I used rtv to seal the straight threads.

It really did help with the harshness but I'm only dealing with helper springs.
I think this is the best option. Increasing the effective volume of the bags is exactly what Java needs I think.

I'd expect you would want a BIG fitting between the bags and the ping tanks, to reduce restriction during high speed compression. As big as you can fit on the bag mounting brackets.
09-18-2019 03:28 PM
Java Ping tanks are in the works.

And yes that's the page! Kelderman sent it to me.... They say I'm just feeling the rear end.... So then why am I only using 2.5" of travel?!?

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09-18-2019 03:22 PM
bdkw1 Hey, that's the catalog I was looking for! They used to be so much better. Note the funky spring rate curve. The last 2" ramp up really quick.
09-18-2019 12:11 PM
FirstRam Reconsider ping tanks. I adapted a 1/2" push to connect to a coupling nut that fit the threads of the hollow mounting stud (3/4-16). I used rtv to seal the straight threads.

It really did help with the harshness but I'm only dealing with helper springs.
09-18-2019 11:43 AM
Java Bag data!!!

A little hard to read, But shows the curves and spring rates. spring rates @ 80psi 535, @100psi 658 (at 9")

09-18-2019 07:45 AM
Java
Quote:
Originally Posted by GLTHFJ60 View Post
I'd say you've found your issue, lol.



Read up. Adding fluid to the bag will not decrease the pressure needed to get the height you require. It will increase the rate at which the spring rate increases as you compress the air spring, because you would have a smaller volume of gas (compressed air).

http://lhtech.com/pdf/automation/pne...pring-Data.pdf
I sure hope thats the issue (and my Oring works... I didn't have one that was "fat enough" it seemed. I doubled up on a A110 )

Thanks, reading now. That was my understanding as well. The size of the surface of the cylinder (air bag diameter) along with the weight supported dictates the pressure.
09-18-2019 07:06 AM
GLTHFJ60
Quote:
Originally Posted by Java View Post
Your fucking shitting me. That's all that's left of the Oring, if there was ever one....
I'd say you've found your issue, lol.



Read up. Adding fluid to the bag will not decrease the pressure needed to get the height you require. It will increase the rate at which the spring rate increases as you compress the air spring, because you would have a smaller volume of gas (compressed air).

http://lhtech.com/pdf/automation/pne...pring-Data.pdf
09-17-2019 07:45 PM
Java Your fucking shitting me. That's all that's left of the Oring, if there was ever one....

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09-17-2019 04:35 PM
Java
Quote:
Originally Posted by bdkw1 View Post
I was trying to find the spring rate curves for those bags but apparently Firestone doesn't publish them anymore. I need to find my old Firestone catalog that had all that info.



And most of the bags I have used have required a little antifreeze to up the progression rate. Granted, they have all been double billow bags. The rolling bags have a funky spring rate curve that I stayed away from.
From what I could find (look at their ordering form) they look really flat across the middle, but I may be just too far to one end.

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09-17-2019 04:24 PM
bdkw1 I was trying to find the spring rate curves for those bags but apparently Firestone doesn't publish them anymore. I need to find my old Firestone catalog that had all that info.

And most of the bags I have used have required a little antifreeze to up the progression rate. Granted, they have all been double billow bags. The rolling bags have a funky spring rate curve that I stayed away from.
09-17-2019 01:44 PM
Java And down the rabbit hole we go.... I finally found Firestone's PDF of Engineering design and guide. Oh boy is it a read....

But I came across this nugget.



So it increases the natural frequency. Humans like higher frequency. Long bouncy = no good. But I don't have that issue. The other is positioning. Not sure I want to be limiting travel IE increasing accurate positioning?
09-17-2019 01:19 PM
Java
Quote:
Originally Posted by 65Chevy4x4 View Post
What I understand about adding antifreeze to bag is that it makes the pressure ramp up faster since there is less volume in the bag. Similar to adding more oil to an air shock. Allows you to run lower pressure when extended and adds spring rate when compressed.
Seems like it would make the spring rate rise much faster. And I don't quite grasp how it would need lower pressure?
09-17-2019 09:47 AM
65Chevy4x4 What I understand about adding antifreeze to bag is that it makes the pressure ramp up faster since there is less volume in the bag. Similar to adding more oil to an air shock. Allows you to run lower pressure when extended and adds spring rate when compressed.
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