Matt16

What is the benefit to a high pressure gas charged shock, I've heard it "pushes" the wheels on to the road etc. but does this truely make a difference?

Also, for fire service/ logging roads, what is the preference for shock valving? I've heard something about Baja racers using really soft shocks in the rear, but what about up front? I don't jump my truck or push it that hard, but I've got a bit of a bad back after a collision with a dump truck, so a comfy ride is nice.

I've been thinking that I might sell my Pro Comp ES3000s and pick and choose from Doetsch Tech, as they list their shocks' firmness.

Alex 400

I just put doestch tech MV12's in the back and bilstein's in the front and it feels great. the back doesn't buck so hard. the MV12's have no push back at all. I had to pull them out so i could put them in. the idea is that the back end plants itself to the ground all the time instead of bucking up and losing traction. I also put the all pro rear coils in as well and everything seems to work well together. Street obstacles like exposed manholes and bumps feel like nothing now. They are great shocks and not overly expensive.

Matt16

Actually I was reading one of your earlier posts, good info. My Pro Comps aren't gas charged either so they don't push back when you compress them either, but the ride still could be better.

bry-an

all that shocks do is absorb the bumps and contain the springs on your truck.... imagine if you just had springs , you would ride like one of those playground toys just keep bouncing after a tiny bump. they do not have the strength to push tires down, thats the springs job. gas charged shocks are better because they transfer and absorb heat better than the old oil style. which means they have less heat fade when running in washboard heavy cycling situations( a cycle for shocks is 1 in and out)



whatever the shock is charged with transfers the kinectic energy of a bump which heats up the charged(pressurized) particles, which in turn disspate the heat through the metal shock body. ...... so the bigger the shock body the more chance for heat to dissapate the better the shock holds up.

elripster

Here you go..

I found this info here http://www.monroe.com/tech_support/t...kabsorbers.asp


Twin Tube - Gas Charged Design
The development of gas charged shock absorbers was a major advance in ride control technology. This advance solved many ride control problems which occurred due to an increasing number of vehicles using uni-body construction, shorter wheelbases and increased use of higher tire pressures.

The design of twin tube gas charged shock absorbers solves many of today's ride control problems by adding a low pressure charge of nitrogen gas in the reserve tube. The pressure of the nitrogen in the reserve tube varies from 100 to 150 psi, depending on the amount of fluid in the reserve tube. The gas serves several important functions to improve the ride control characteristics of a shock.

The prime function of gas charging is to minimize aeration of the hydraulic fluid. The pressure of the nitrogen gas compresses air bubbles in the hydraulic fluid. This prevents the oil and air from mixing and creating foam. Foam affects performance because it can be compressed - fluid can not. With aeration reduced, the shock is able to react faster and more predictably, allowing for quicker response time and helping keep the tire firmly planted on the road surface.

An additional benefit of gas charging is that it creates a mild boost in spring rate to the vehicle. This does not mean that a gas charged shock would raise the vehicle up to correct ride height if the springs were sagging. It does help reduce body roll, sway, brake dive, and acceleration squat.

This mild boost in spring rate is also caused by the difference in the surface area above and below the piston. With greater surface area below the piston than above, more pressurized fluid is in contact with this surface. This is why a gas charged shock absorber will extend on its own.

The final important function of the gas charge is to allow engineers greater flexibility in valving design. In the past such factors as damping and aeration forced compromises in design.

Advantages:

* Improves handling by reducing roll, sway and dive
* Reduces aeration offering a greater range of control over a wider variety of road conditions as compared to non-gas units
* Reduced fade - shocks can lose damping capability as they heat up during use. Gas charged shocks could cut this loss of performance, called fade

Disadvantages:

* Can only be mounted in one direction

Current Uses:

* Original equipment on many domestic passenger car, SUV and light truck applications

Matt16

I've got the impression that pressurized gas charged front shocks combined with soft rear shocks give good handling and a comfortable ride on washboard/ potholed gravel.

elripster

I would agree. The more aggressive valving allowed by nitrogen charging can be good for the potholed roads.

Frank

Matt16

Frank, I remember a while back you said you were running Doetsch Tech shocks. Do you have the part number for the DT 9000 Series (gas charged ones)?

The numbering of the series (3000, 9000) is similar to Pro Comp. These aren't simply from the same supplier are they- as in Procomp gives you their sticker, DT gives you theirs)?

bry-an

I really like the ome n98's that I put on my front. they are nitrogen charged. the main great thing about them is I can rip on the the logging roads for hours and they dont have shock fade like regular ones... so after an hour its the same instead of turning to crap 30 minutes in