Shock maintenance means evaluating...
Shock maintenance means evaluating and maintaining all of the parts and pieces of the racing shock. Replacement of all seals and O-rings is wise. Let's take a more holistic approach to shock maintenance.
Shock maintenance should not be left to the end of the season, but often that's the case. Now that we have a chance to take a deep breath and look over all our systems, it's a good time to do an assessment of our shock needs and what kind of maintenance we need to do to improve on performance.
Shocks are, at best, a tuning tool and many teams have taken this a little too far and asked the shock to act as a manipulative device. We see teams trying to "tie-down" the left front corner or the left rear of the car. The only way to tie the left front to the track is to bolt the tire to the asphalt, and we know that's impossible. All we are doing when we restrict the rebound movement of the suspension is to lock that suspension solid. Load will still transfer from the left side to the right in the turns, but the left suspension will not move.
Many think this lack of movement means no load is transferring, but like a racing kart, load does transfer and in much larger quantities than if the suspension were allowed to work. The benefits of that methodology are hard to quantify. Nonetheless, whatever shocks you run, you still need to maintain them. Here are some ideas for selection of shocks and how to evaluate the efficiency and rebuilding of racing shocks.
Dings on the outside of the...
Dings on the outside of the shock body can have a reshaping effect on the inside wall. Any time your shock takes a lick and shows a dent, remove and take the shock apart and inspect the inside wall.
EVALUATION We first want to evaluate how our shocks performed during the past season. Are they doing the same work now as when they were installed some 10 months ago? Did our setup change as the season progressed and did we keep up with those changes by modifying our shocks? Did we have failures in our shock package and what can we do to prevent failures in the future?
Go over your notes and see what shock settings you ran throughout the season. Make notes based on the chronology, or timeline, of events to see trends in the changes you made. Note any failures of any one shock and the corner that was affected.
If your basic setup changed during the season, note how it changed and what, if any, changes were made to the shock package. If no changes were made, now is the time to re-evaluate your package to better enhance the newer setups.
We know for a fact that the same shock package can't work for both conventional setups and BBSS setups. Simple shock technology tells us that the springs resist compression and promote rebound. So, the shocks must change in their compression and rebound rates to compensate for spring rate changes.
This is the same shock body...
This is the same shock body showing how the dent on the outside transferred a bulge to the inside wall. This could affect the motion of the piston.
A higher spring rate at one corner will necessitate a higher amount of rebound control and less compression control to keep the same motion characteristics. Many professional teams from the NASCAR Truck series up to the Cup level use fixtures where they can install the spring and shock in the true motion ratios used in the car to rate the combination of springs and shocks. This method gives us a true picture of compression and rebound related to the wheel.
INSPECTION OF EXTERIOR An outside visual inspection is necessary to determine if any damage has been done to the shock. For sealed shocks, we will not be able to inspect the inside, but we can have them dyno'd and inspected by a factory authorized tech center or the manufacturer.
If you're using adjustable shocks, note and record the settings before you go any further. These are the settings you ended up with and probably will start with next season. Don't forget to write down what you have. Once you start the maintenance part, these settings could end up being changed.