By Sleepy Gomez

A gas-cell shock, or a gas-charged shock with a floater piston, can be run upside down, right side up, or lying on its side, according to AFCO.

Each month, Stock Car Racing visits with a racing manufacturer to find out what questions they are most frequently asked. This month we went to Bill Workman of AFCO Racing Products.

 

Q: How long can I run my rebuildable shocks before they need service? For that matter, how long should I run non-rebuildable shocks before replacing them?

A: A quality racing shock should last a weekend racer at least a full season of, say, 25 shows of 30-lap mains.

 

Q: When can I run my shocks upside down?

A: Any gas-cell shock or gas-charged shock with a floater piston can be run upside down, right side up, or lying on its side. Almost all of the popular bearing-mount shocks on the market are this type. Some stock-mount shocks have to be run right side up; but, to mount in the stock location, you have to mount them right side up anyway.

 

Q: Does the valving change when the shocks are inverted?

A: No, compression is always in and rebound is always out, regardless of mounting position.

 

Q: Do I need a shock dyno?

A: If you are not rebuilding your own shocks, you don't need to spend the money. Go with a shock company you're confident about, and have them maintained regularly.

 

Q: Should I be rebuilding my own shocks?

A: Not without a dyno, a clean work environment, and some basic training. Most shock companies offer classes for this operation.

 

Q: How much softer does a shock get when I lean it in?

A: A good rule of thumb is 10 percent for every 5 degrees of angle.

 

Q: Can I change the amount of weight my wheel receives by changing a shock?

A: No. You will only change the speed at which that wheel loads or unloads. Spring rates determine how much weight transfers.

 

Q: Which is best, a monotube or a twin-tube type of shock?

A: Both types have their pros and cons. It would require another article by itself to explain all of them. Check with your shock manufacturer or chassis builder to help determine which is best for your application.

 

Q: Is a dented shock still good?

A: If it's a twin-tube shock and you can still move the shaft in and out, it's OK. Monotube shocks cannot take dents.

 

Q: Should I use split-valve shocks?

A: Shocks are a fine-tuning adjustment. A correctly chosen split-valve shock will help only a race car that's pretty close on setup. No shock change will take you from last to first.

 

Q: What do the terms "tie down" and "easy up" shock mean?

A: A tie-down shock has more rebound than compression. An easy-up shock has less rebound than compression.

 

Q: If I have a shock that's leaking a little, how low can it get on fluid before it goes bad?

A: If you have a leaking shock, it's already bad.

 

Q: Is it cost effective to repair a crashed shock?

A: As long as the body of the shock is salvageable, it's usually cost effective to repair the shock.

 

Q: When I have the option (per track rules) should I use steel- or aluminum-body shocks?

A: Aluminum shocks are the way to go. They are repairable, which makes them less expensive in the long run. Aluminum shocks also run cooler than steel shocks, making them better from green to checker.

 

Q: Should I run shock covers?

A: No. Heat is the enemy, and shock covers trap heat.

 

Q: If I convert between gas pressure and twin-tube shocks do I need to change springs?

A: It will depend upon the rod pressure in the gas-pressure shocks. Different shock manufacturers use varying amounts of gas pressure in their shocks. Consult your shock manufacturer to determine if the rod pressure warrants a spring change.

 

Q: How much shock shaft should I have showing at ride height?

A: No less than 311/42 inches is a good rule of thumb.

 

Q: If the paint has been rubbed off the shock by the tire in tight mounting quarters, is this shock damaged?

A: If the shock is a gas-cell, twin-tube design, the odds are good the cell has already melted and ruptured due to the heat generated. If it is a gas-pressure, monotube shock it will last a little longer. Continually boiling the fluid will always lead to premature shock failure. Correct the mountings to keep the tire from rubbing the shock.

 

Q: Is it OK to mix brands of shocks on my race car?

A: Each manufacturer has a slightly different code system [specifying rates]. Though they are generally close, it is recommended you stick with one brand for consistency.

 

Q: Do I need adjustable shocks?

A: If you are a traveling racer, they are a must. Whatever the track conditions you find, you can tailor the shocks to fit. If you always run the same track, get one for the front and one for the back.

 

Q: If I'm getting wheelhop, is it a shock problem?

A: Wheelhop is often caused by using a shock that's too soft. Also, a severely worn shock will cause the problem.