Long Travel information.

Some LT guys haven't done the rear of their trucks yet, and many of the ones that have haven't spent the time to dial in the shocks. Proper shock valving has a lot to do with it.

The video posted by MonkeyProof is an excellent comparison of how most trucks perform versus how a properly setup truck should run.
http://www.tacomaworld.com/forum/tacoma-videos/53920-all-pro.html#post971490

Watch the pass at the 2:00 mark, and then watch the blue truck fly through the same section at 2:30. The difference is night and day.

Last year I took my truck through Barstow and broke bad. It was set up completely wrong both front and rear and was punished for it. That blue truck was with us that day and flew through the sections that snapped my suspension. He seemed to float over the terrain.

Test and tune is huge after the build is complete, but most guys pick up their rigs from the shop and start beating on them without dialing them in. To be fair, they have a freaking blast doing it too! I understand since that's exactly what I did, but on my setup it was clear I had some major rework to do as I flat out had the wrong suspension system for the terrain and it just wasn't enjoyable.

I've made some huge changes in the past year, and I've got many hours of that ahead of me before I enter another race.

 

I'm not purposely avoiding this question. I've just been really busy with work and it's going to take some time to explain this properly.

I'll post up a proper response in the next several hours.

 

Increasing the amount the vehicle's suspension cycles beyond the installation of shocks or coilovers. On IFS it usually involves wider upper and lower control arms and all the peripheral stuff to make it work properly. On solid axles, it involves installing longer, softer leaf springs or a 4-link suspension.

 

You want the suspension to absorb as much of the terrain as possible without allowing the vehicle to bounce all over the place. The more the tires stay in contact with the ground, the more control the driver has over the vehicle.

Shock valving and tuning is dependent on vehicle weight, unsprung weight, spring rates, wheel travel, anticipated terrain, etc. Most race and many built desert play vehicles run bypass shocks. These allow for external adjustments and varying levels of dampening at different points in the suspension travel.

The bypass tubes allow the shock oil to flow around the internal shim stack in the shock body. The location and the valving of each bypass tube determine where in the shock travel, in what direction, and how much fluid flows. Through that it's possible to increase or decrease dampening at different points on either the compression or rebound stroke.

Below is a picture of some 3-tube bypass shocks with remote reservoirs:


On these, the 2 blue valves are for compression and the red one is for rebound. Note how the tube ends are staggered. Shock oil flows through a tube when the internal shock piston is between the two ends of that tube. In the case of these specific shocks, oil flows through both compression tubes during the initial compression stroke. Once past the end of the shorter tube, oil only flows through 1 tube and thus provides more dampening as the suspension compresses. When the internal piston passes the end of this tube, the internal shim stack alone controls the dampening and the shock can act like a hydraulic bumpstop.

Externally adjustable valves on each tube allow for easy tuning without the need to disassemble the shocks or even remove them from the vehicle. During testing, it helps to video record multiple passes over the same terrain between adjustments to see the effects of the tuning beyond just vehicle feel.

Shock temperature also factors into the equation. As shocks heat up they lose dampening. Generally speaking, larger diameter remote reservoir shocks hold more oil and resist overheating better than smaller diameter emulsion shocks. Bypass tubes also increase surface area to dissipate heat and further reduce shock fade.