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What's your tune?

Picking the right shock for your purpose-built ride

Story Eric McClellan / Images Eric McClellan and Ridetech - June 27, 2013 10:00 AM

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Blue is oil, the speckled area is nitrogen gas, grey is the floating piston. At high shaft speed, the nitrogen gas keeps the oil from cavitating. This monotube style allows for more oil volume.

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The small diameter twin-tube design employs a valve at the bottom of the inner tube. These typically heat faster, retain more heat and tend to fade quicker while in use.

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The differences of a twin-tube and a monotube shock. The robustness of the monotube creates a much more durable and reliable piece.

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Cutaway of a monotube shock design by RideTech. The size of the parts makes these types of shocks a lot more durable. They have built in bump stops and you can see the lower floating piston that separates the oil from the nitrogen gas.

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We started with QA1 single adjustable coilovers. These are great for street use, but lacking of extra adjustments to squeeze every ounce of speed out of the car.

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Our RideTech triple adjustable shocks and coils preassembled. The obvious difference is the external reservoir that locates the high and low speed compression knobs.

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The shocks come with different sizes of machined eyelets to accommodate virtually any coilover system on the market. The knob at the top of the shock is your rebound adjustment. 

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We were able to dial the overall height of the front of the car in very small increments. It helps to do this with the weight off the tire you’re working on.

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Once you’ve found a good spot for your reservoir, you’ll need to make sure the braided line is away from any moving parts and heat.

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The outer ring is the high-speed compression and the inner knob is the low-speed variant. Ridetech suggests that you use as little compression as possible and what’s comfortable for you.

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Before you get started, it helps to measure ride height and write it all down so you know where to set it up as a baseline.

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Think back to the first time you put the pedal down and felt the roar of the engine and the g-forces on your body.

That existential experience was enough to have you completely hooked on the speed bandwagon.

The shock and spring package you pick could be the most important decision you will make when it comes to the actual performance of your car. If you can’t put the power down, even a 1,000hp twin-turbo monster will just break loose. How much fun is that after about half a dozen burnouts at 65mph? Nah, having all 1,000 ponies hit the ground running is way more exhilarating.

This quick little guide will walk you through picking the most appropriate shock for your application. We consulted the biggest name in Pro-Touring shocks and springs, Bret Voelkel and Herb Lump of RideTech, to break down some of the options on the market.

 

Non-Adjustable

The non-adjustable shock is pretty self-explanatory. You get virtually no adjustments and you are pretty much stuck with whatever valving came from the factory. Depending on your application, these could be fairly decent, but most of them attempt to have a balance between performance and ride quality. The best application for these shocks is typically the bone-stock restomod or stock rebuild.

 

Single Adjustable

We started off with a set of QA1 single adjustable coilover shocks on our project 1968 Camaro that allowed us to adjust the rebound or “extension” portion of the shock. We found that after a few track sessions we were able to dial them in for the circumstances, but we really started to feel limited in our ability to dial in more speed.

We did appreciate the ease in which we were able to adjust the ride height and ride quality. The cost was fairly reasonable when all things are factored in. This set-up is a direct step up from the stock shock and spring package or even a performance non-adjustable shock. We suggest this coilover set-up for the typical street guy who wants a performance feel, the ability to dial in performance without too much complication, and may see an occasional track day once or twice a year.

 

Triple Adjustable

We had the opportunity to upgrade our single adjustable shocks to a much more venerable triple adjustable version from RideTech. First thing you’ll notice is that these have a 30-inch braided hose reservoir attached to one end, so you’ll need to plan on how to mount them away from heat and road damage. Setting the ride height is exactly the same as any other coilover, but the feel of the car completely changed after we upgraded.

After a few adjustments, only adjusting one component at a time, we could really start to see the possibilities built into these shocks. The step up from a single adjustable to a triple is a major leap in complexity. We got lost on more than one occasion, on which way adjustments should go to produce what effect. Sometimes not having the option to make adjustments makes us feel better about our lack of tuning ability.

The RideTech triple adjustable shocks are really built for the serious performance driver. This shock and spring package can easily be four or five times more expensive than a non-adjustable coilover package. That said, if you’re resolute in tuning your suspension and getting every last ounce out of your ride and you see more track time than the average Thomas the Tank engine, then these are for you.

 

On springs

A bad spring can easily ruin any shock adjustments you make. For example, if you have a spring that is too soft, you’ll bottom out and won’t be able to retain ride height. While ride height is somewhat adjustable by setting the preload, it’s not a magic cure for the wrong spring. We suggest calling and taking suggestions from the manufacturer as to what they recommend for your application.

 

Shock Tuning

As much as we would love to give you hard and fast rules as to what set-up works best for which car, we just can’t. There are so many variables in shock tuning. For example, the set-up that we prefer may be a lot more loose than someone else’s, even in the exact same car! Also, driving style has as much to do with shock tuning as the shock itself.

It helps to think of the shock and spring package as a “timing device”. It controls how fast or slow the tire responds to different conditions.

Another way to think of it is the shock and spring is the force keeping your car off the ground; it counteracts the forces of gravity. When you go around a turn, accelerate or brake, you change the balance of the car, which puts greater or less force on the shock and spring, which has to counteract the force.

The two major forces when it comes to shocks are rebound and compression. Compression is when the suspension compresses. This occurs when you hit a bump in the road. The bump forces the wheel/tire/suspension assembly to “compress” or move upwards into the car. Likewise, in a braking situation, the front is being compressed.

Rebound is the opposite, when the wheel/tire/suspension assembly falls into a pothole, or simply “rebounds” from being compressed. In our same braking example, the rear is being pushed up or “rebounding”.

Single adjustable shocks will only allow you to adjust the rebound of the shock or how fast it snaps back after being compressed. The compression end of things has been set for you. The triple adjustable shock that we have on our project Camaro has not only rebound adjustment, but high and low speed compression settings. High speed compression is more or less used for tracks or events that have a lot of potholes or isn’t a very smooth surface and has minimal effect on the other adjustments. Low speed compression is more likely going to be your best bet for purpose-built racetracks that keep a well groomed surface and the compression rate is more or less predictable and smooth.

RideTech makes a solid suggestion when starting off with a baseline tune. They told us that since the movement of the shock, when compared to the wheel, is 2:1 in the front and virtually 1:1 in the back. This means that to keep the car balanced, you’ll typically want to have the damping force twice as much in the front as the rear.

RideTech also suggests running as little compression damping as possible. Their theory is that the spring is already doing most of that kind of work.

We’ve seen many times at the local autocrosses and races where a guy gets a new set of shocks and springs and thinks, “The stiffer the better!” Unfortunately, this just isn’t true. Often times, the stiffer the shocks, the more the car will slide around and push too hard in the corners. You need to allow for some movement in the suspension for it to accurately do its job properly.

As a general rule, the rear shocks have the most influence on ride quality. It also makes sense that the front shocks will usually have a much firmer setting all around than the rear because the front shocks hold twice the weight. Also, it’s best to make adjustments in three to four click segments, as most adjustments are so minimal that you won’t notice them.

Your zero setting is all the way clockwise (by going counterclockwise, you are essentially making the setting “softer”). Set your baseline tune (we suggest somewhere in the middle) such as 12 clicks out of 25, for compression in the front and 18 in the rear. If the car is really pushing the front through the corners, you may want to soften things up in the front. Or, if you’re coming out of a turn and the rear body rolls too much and doesn’t want to swing around, you may need to stiffen it up. The answer to all of these questions is seat time and knowing WHAT to adjust.

We went to Jay Weir of Speedtech to help us get a grip on how to adjust our way out of a paper bag. He gave us the basics on where to start when it comes to adjusting the suspension. You may need to fiddle with a lot of these settings to really get a feel for what everything does.

 

Oversteer

Oversteer is where the back end of the car wants to come around before you want it to. Power oversteer is where you give it too much gas and break traction of the rear tires. Oversteer at corner entry would lead to a front shock adjustment and with exit corner traction issues you’ll want to look into rear shock adjustments.

 

Understeer

Understeer is essentially when the car is not turning as much as you want. In cases of understeer, you may want to soften the front (decrease the amount of compression needed) in the front of the vehicle. This allows more weight transfer to the front of the vehicle to allow the tires to bite a bit more.

 

The Bottom Line

Nothing will affect the quality of the feel of your car than shocks and springs. They are the buffers between your butt and the pavement. All of the shock packages that we’ve tested serve their purpose, but they all have their advantages and shortcomings.

Our biggest suggestion we can give you is to really take a hard look at what you want your car to do. If you have a fixed shock or single adjustable coilover and are serious about performance, a jump to the triple adjustable shocks might be worth it. But, if you just want to look good and cruise the strip, stick with the singles.

 

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