Quote:
Originally posted by Hellbender
Good morning Frank,
Looks like you are going to have a blast playing w/ that set-up!
I have a question on the artificial side to side (L to R and R to L) angle inducement, are you measuring this on LEVEL ground with both left side springs @ 0 pressure and both right side springs at max. pressure ? If so, how would the (tire) track width affect this measurement (on level ground)?
The only way to affect this would require the spring mounting points to be changed, not the track width (again, on level ground).
Wheelbase changes would affect the angles IF the spring mounting points were moved to correspond with the axle movement.
Obviously, on uneven ground, ANY width or length increase would increase overall stability (all other things being equal), but not necessarily the body angle changes in relation to the axle you've discussed.
Maybe I am not fully understanding your explanation.
HB
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Hi Brad,
Good questions, I guess in hindsight my comments were a bit confusing.
To begin with all of the artificial angles where measured on something close to perfectly level (The concrete slab which forms my garage floor.)
In each case the down side (or lower side) air springs were set at their minimum operating pressure of 30 PSI. I am certain the angles would be greater if air down to 0 PSI and allowed to sit on the bump stops, but I would never plan to operate this system in that way.
The high side was aired up to 80 PSI which is below the 100 PSI maximum operating pressure.
I limited the PSI to 80 in these angle measurement for two reasons. I wanted to have a certain degree of built in safety factor in any calculation I use these angle for. I also think I need to allow for pressure increases above 80 PSI that will be caused by compression while actually Jeep'n.
Your observations are right about the angles changing somewhat when not on level ground. But even on level ground there are some variables in that as one side is raised it does not go straight up X number of inches but rather travels in an arch around the low side pivot point.
What I attempted to explain was the angle differences between the side to side and front to back artificial angles.
Becuase the distance between the raised end and the pivot point is greatly different between side to side (let say 66 inches) and the wheelbase (approximately 95 inches) raising one side or raising the front or back by the same number of inches results in greatly different angles.
Take a stick 65 inches long and raise one end 10 inches.
This angle will be far greater then taking a stick 95 inches long and raising one end the same 10 inches.
Thanks for reminding me that I need to be more complete when writing things like this, particularly in this regard on what air PSI I used when taking the angle measurement and my logic in what I used.
Have a great day my friend.
Frank
PS: I also need to write a few warnings and hopefully create a better understanding of what happens (to roll over angles) when lifting and lowering each side.
Briefly, it is always safe and beneficial to LOWER the high side, BUT it is NOT Always Safe or Beneficial (to roll over angles) to Raise the Low Side.
Hopefully I will be able to explain the geometry and logic of this shortly in a clear way.