Phil's Inc. offers Light Racing Jounce Shocks

 

Rod Ends & Dimple Dies - Coilover Shocks

What to expect from your JounceShock

The JounceShock is the core of a secondary suspension system that dramatically increases the capacity of your vehicle’s suspension. Most systems are designed such that the JounceShocks do not engage the suspension of your vehicle at ride height. Therefore the system does not usually alter the ride height or on-road ride quality of your vehicle. When you have a heavy payload or take your vehicle off-road, your suspension will compress more and engage the JounceShocks. When the suspension engages the JounceShocks, you may hear the initial contact. This is normal and is an indication that the JounceShocks are being applied. As the vehicle is driven off-road you will notice a couple of performance gains. First, as you drive the vehicle over rough terrain you will notice that it never feels as though the vehicle is bottoming. Also, you will realize that the vehicle moves up and down lessЙ ТGross Vehicle Motion ControlУ as it is called. These are changes caused by the characteristic exponential air spring curve and the critical damping of the JounceShock units. These changes significantly enhance the ability of the vehicle, the durability of the vehicle, and the comfort level of the occupants. This added capacity can be misleading and care should be taken to learn the new limits of your vehicle without damage to the vehicle itself.

How a JounceShock works-
When the suspension compresses it drives the shaft of the JounceShock into the JounceShock body. The shaft compresses the nitrogen volume and since the nitrogen is in a closed cylinder, the nitrogen pressure increases dramatically as it compresses. This gives a smooth exponential increase in force (like an air spring) instead of the force spike that occurs when typical suspension systems bottom out. The valving inside the JounceShock is designed such that after the JounceShock has compressed the suspension falls away faster than the JounceShock can extend. Therefore all of the energy that was put into compressing the JounceShock is dissipated by the valving rather than pushing the suspension back out. This is a key factor in why the JounceShocks are so effective for high energy absorption and vehicle control.

Technical Information and Installation Tips

Tuning the JounceShock-
The JounceShock comes with a general tuning that should work well in most applications. However, vehicle handling and dynamics is a matter of personal preference and this system can be tuned to suit individual tastes and uses. There are four parameters of the JounceShocks that may be tuned; the initial nitrogen pressure, the compression damping, the rebound damping, and the oil fill.

Tuning Nitrogen Pressure-
The primary tuning parameter, and the one that makes the biggest performance difference, is the initial nitrogen pressure or charge. The nitrogen can be discharged and recharged to a different setting. To do this the JounceShock must be removed from the vehicle, but it does not need to be disassembled. The oil in the JounceShock is mixed with the nitrogen so care should be taken when discharging the nitrogen to assure that no oil is lost. It is recommended that the JounceShocks be stored with the shaft end (Schrader valve) up for 20-30 minutes prior to being discharged. This will allow the oil and nitrogen to separate and the oil to fall to the bottom of the JounceShock. Then the JounceShocks may be carefully and slowly discharged while keeping the Schrader valve upright to avoid oil loss. Access to the Schrader valve is gained by removing (unthreading) the contact foot at the end of the shaft (e.g. Domed Foot or Cupped Foot). You will see a yellow Schrader valve cap recessed in the end of the shaft.

The yellow Schrader cap must be removed to access the Schrader valve for both charging and discharging. A Fill Extension (#25515) is required to charge the JounceShock as the Schrader valve is recessed in the end of the shaft. The nitrogen charge in the JounceShock is preset at 80 psi for the 3" travel (#25715) and 150 psi for the 1.5" travel (#25710) . We do not recommend charging below 40 psi or above 500 psi. Screw the Fill Extension onto Schrader valve body and snug hand tight to get a good seal. (Warning: Care should be taken when installing and removing the Fill Extension. Over tightening of the Fill Extension could cause the Schrader body to back out when removing.) Nitrogen is recommended for charging as it is inert and has good temperature characteristics. An air chuck will work to charge the shock by engaging the end of the Fill Extension. Set the nitrogen tank regulator to the desired pressure and engage the air chuck long enough to assure that the pressure has equalized in the JounceShock. Remove the air chuck quickly to minimized pressure loss.

Tuning Compression and Rebound Damping-
Compression and rebound damping can be adjusted externally without removing the JounceShock from the vehicle. There are two ports crossed drilled in the shaft end that accept a 1/8У hex key. These ports are shown in Figure 3. The compression damping port is marked with a ТCУ and the rebound is marked with an ТRУ. Turning the adjuster clockwise will increase the damping. These adjustments are for fine tuning and can be turned all the way in (clockwise) or all the way out (counter clockwise) up to the snap ring retainer. Care should be taken when adjusting to full open so as to not force the adjuster past the snap ring, causing possible depressurization.

Tuning Oil Fill-
Oil level in the JounceShock is set at the factory. The oil level is adjustable, but tuning of oil level is complex. The factory setting for the oil level will work in the majority of applications.

The easiest practice is to measure the oil drained during rebuild and refill The JounceShock with the same quantity of oil. Oil may be purchased separately (Torco Shock Oil Part No. T830007).

See Rebuild Kit instruction sheet 98712 for more information on disassembly and reassembly.

Determining location-
Generally speaking the JounceShock should be located such that the cylinder (large end) is permanently attached to the chassis of the vehicle. The position of the JounceShock is determined by the vehicle suspension. The shaft end (small end) of the JounceShock should be driven by an area of the suspension that is strong enough for the forces that will be seen. Typically this means that the shaft end will be contacting the axle housing, lower control arm, or other major suspension component. In most applications, the Jounceshock is positioned so that it is engaged in the last 1/4 to 1/3 of suspension travel. The JounceShock should determine the limit of the suspension travel in compression, the maximum desired suspension position should coincide with the JounceShock being fully compressed. Since the highest forces are experienced when the JounceShock is fully compressed, the unit should be mounted parallel to the direction that the suspension is moving at full compression or as close to that as possible. This limits the side loading that the JounceShock experiences when the pressures are at their highest which in turn increases durability and load capacity.
Mounting JounceShocks

Cylinder End Mounts   #25505 FIXED MOUNT The Fixed Mount assembly can be welded to your mounting point. It will provides a simple attachment point for your JounceShock. The Fixed Mount will most often be used with the the Domed Foot on the shaft end of the shock (part #25602.) Click here for more dimensional and technical data. $15.96   #25501 15 degree FLEX MOUNT The 15° Flex Mount assembly can be welded to your mounting point. It will give you 7.5° of articulation in any direction during compression and center the JounceShock during rebound. The 15° Flex Mount will most often be used with the the cupped foot and target on the shaft end of the shock (part #25601.) Click here for more dimensional and technical data. $71.96   #25530 FRAME SIDE MOUNT The Frame Side Mount provides a versatile weld or bolt on option to mount your JounceShock in a fixed position. Click here for more dimensional and technical data. $91.96   #25508 COIL CARRIER / BOLT UP MOUNT The Coil Carrier / Bolt Up Mount can be sandwiched in your spring seat or bolted to the bottom of a frame. This is the mount you need if you are using JounceShock with LG Coilovers. Click here for more dimensional and technical data. $39.96

Shaft End Mounts   #25602 DOMED FOOT The Domed foot screws directly into the shaft of the JounceShock. This is the most traditional of bump shock ends and is most often used in an application with some scrub on a solid target. It can also be used in conjunction with the Shaft Extender #25603 below, Click here for more dimensional and technical data. $19.96 #25601 Cupped Foot & Target The Cupped Foot and Domed target is a bolt on target for the shaft end of the JounceShock. It will target the JounceShock for 30° of motion as your suspension travels. Click here for more dimensional and technical data. $35.96 #25608 Target Plate Convenient size to accommodate JounceShock articulation when used with Domed Foot (sold separately). Click here for more dimensional and technical data. $7.16 1 - 7 inch JounceShock Extender   The JounceShock Extender is a cut to length adapter that will add 1" to 4" inches to the shaft of your JounceShock. This will permit you to finely control when your JounceShock comes into contact as well as offer a thinner tube to stab at a target. Click here for more dimensional and technical data. CALL

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