Hydraulic bump-stops..

[DylanICON]

Interesting stuff... So if I understand correctly, your assertion with running a 2.5" bump requires less psi so it's comfortable, but the trade off is now a slow rebound which results in packing up? Do I have this right???

Not necessarily.
Pressure IS a means to tune a bump but if too far from where the piston tuning and oil volume were meant to operate it could be a problem. The important point is that there is more to dissipating the energy then PSI and body diameter.

 

[Raptizzle]

I'm confused then.

 

[MTUH3]

My understanding from reading the bump stop numbers is the travel length of the bump stop, not necessarily the width. For example company A Uses 3 different bump stop numbers, each talking about the 2.5" 3" and 4". All have the same body DIA, but different shaft length and stroke. They use valving, pressure, and travel length of the bump stop to control how much energy is being absorbed.

It appears that the advantage to the hydraulic bump stop is the curve shape, allowing more energy to be dissipated sooner in the bump travel, but like an air bump, valving, pressure, and travel play roles.

Going to a larger DIA shaft is only needed when the energy can't be controlled within the current constraints of the shaft / body.

At least this is how I understand Senior Shock Guru

 

[DylanICON]

My understanding from reading the bump stop numbers is the travel length of the bump stop, not necessarily the width. For example company A Uses 3 different bump stop numbers, each talking about the 2.5" 3" and 4". All have the same body DIA, but different shaft length and stroke. They use valving, pressure, and travel length of the bump stop to control how much energy is being absorbed.

It appears that the advantage to the hydraulic bump stop is the curve shape, allowing more energy to be dissipated sooner in the bump travel, but like an air bump, valving, pressure, and travel play roles.

Going to a larger DIA shaft is only needed when the energy can't be controlled within the current constraints of the shaft / body.

At least this is how I understand Senior Shock Guru

Yes

Energy = Force X Distance

If we simply dropped a truck from 10 ft we could take the potential energy of the mass of the truck at that height and equate it to (force X the travel of the suspension) for it to land and dissipate the energy.

But because we are in a more dynamic and varying situation that force would be way to high and would disrupt the chassis over every obstacle so we have velocity and position sensitive shocks and bump stops. A longer, bigger, high pressure bump stop will handle massive hits better but is more likely to upset the attitude and handling of the vehicle the rest of the time.

Here is a great example:
From 1:00 to 2:30

Ford Raptor Icon Testing - San Felipe, Mexico - YouTube

The best riding truck in this video is Theresa's truck. Why? It has an aftermarket spring that removed the block which has the arm on the side that engages the factory bump and there is no bump kit. So essentially there is NO bump stop, just shock and spring. This truck has more uninhibited up travel then the rest so within a certain range it is great. The problem is that prior to this trip she broke the upper shock mount from bottoming the shock in Glamis where there are big huge jumps and hard landings. For this trip we adjusted the long compression tube on the shock to dissipate more energy so she wouldn't bottom the shock as easily but it still needs a bump and would bottom on big hits.

 

[Squatting Dog]

Yes

Energy = Force X Distance

If we simply dropped a truck from 10 ft we could take the potential energy of the mass of the truck at that height and equate it to (force X the travel of the suspension) for it to land and dissipate the energy.

But because we are in a more dynamic and varying situation that force would be way to high and would disrupt the chassis over every obstacle so we have velocity and position sensitive shocks and bump stops. A longer, bigger, high pressure bump stop will handle massive hits better but is more likely to upset the attitude and handling of the vehicle the rest of the time.

Here is a great example:
From 1:00 to 2:30

Ford Raptor Icon Testing - San Felipe, Mexico - YouTube

The best riding truck in this video is Theresa's truck. Why? It has an aftermarket spring that removed the block which has the arm on the side that engages the factory bump and there is no bump kit. So essentially there is NO bump stop, just shock and spring. This truck has more uninhibited up travel then the rest so within a certain range it is great. The problem is that prior to this trip she broke the upper shock mount from bottoming the shock in Glamis where there are big huge jumps and hard landings. For this trip we adjusted the long compression tube on the shock to dissipate more energy so she wouldn't bottom the shock as easily but it still needs a bump and would bottom on big hits.

She is one hell of a driver! I would put her up against most people on FRF, and she would win..

My question is, since both of our Raptors blew out our upper shock mounts. Her does not have a bumpstop, and mine does. Both of our damage was eerily similar, what is causing it? What adjustments do I need to make on the shocks?

-Greg (aka squatting dog)

 

[DylanICON]

She is one hell of a driver! I would put her up against most people on FRF, and she would win..

My question is, since both of our Raptors blew out our upper shock mounts. Her does not have a bumpstop, and mine does. Both of our damage was eerily similar, what is causing it? What adjustments do I need to make on the shocks?

-Greg (aka squatting dog)

Aside from the fact that you have amazing luck????????

The repair we did is stronger now than it ever was. I don't think you need to do anything.

The shock mounts don't always need to be clearanced and when they do it is a clearance as needed situation. "As needed" is a little vague and I've seen some very generous clearancing so I have made a template. Where they tend to break is actually quite a bit above where the clearancing is. It's a problem when the radius under the tabs are compromised but that area doesn't need to be touched. They are not all that strong anyway.