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Chassis Heeltoe Explains

Stock shocks with Sport Springs : Yay or Nay?

Abstract

Back in the mid-’90s when I started with this import stuff, we did not have much choice. Lower the car with shorter springs. Usually, with shorter, you get stiffer too. Both these factors will improve the handling of the car. The problems with lowering a car on sport springs with stock shocks are pretty significant, though. Besides the fact that the stock shocks are not designed to accommodate the lower ride height of sport springs, they are often valved wrong and will not provide the performance or longevity you expect from a sports suspension. You’ll end up replacing the dampers sooner and pay more labor in the end.

I am asked this question frequently, and I have an answer.

Nay.

Back in the mid-’90s when I started with this import stuff, we did not have much choice. Lower the car with shorter springs. Usually, with shorter, you get stiffer too. Both these factors will improve the handling of the car. The problems with lowering a car on sport springs with stock shocks are pretty significant, though.

#1 Reduced Travel

The stock dampers are designed to work within a given travel range. They will stroke up and down as the car goes over bumps. This movement is needed to maintain a good, safe ride. By lowering the car you are actually moving the range that the shock is asked to work under. You are asking the dampers to do something they are not designed to do by working them in a range that is smaller than they normally do. And one result of this is “bottoming out.” When the shocks compress completely they bottom out, and the car crashes on the bump stops. This causes the car to pogo and bounces over bumps in the road, drastically hurting the ride and performance of the car. It is highly recommended to use dampers that are short-stroke or short-case with lowering spring to maintain travel in the damper system.*

#2 Degraded damper life

Speaking from experience, dampers in import cars generally last a very long time under normal conditions.

I have seen numerous Accords, Civics, etc go well beyond 100,000 miles with the original shocks only showing hints of softening. You know a shock goes bad when the car seems to float around like a boat as though the springs are allowed to oscillate freely. The shock/strut system is designed to match the stiffness of the spring and keep it in check. The spring compresses to absorb bumps, and it expands to maintain contact with the road over dips. The shock is there to keep the spring from exhibiting natural perpetual motion which would allow it to bounce up and down forever.

The combination of lowering the car into a modified travel range, and making the spring firmer (disrupting the stock shocks/spring balance) combine to cause advanced wear in the shocks. A shock that might normally last 10 years now won’t last 6 months under normal driving conditions.

Here it is recommended that shocks be replaced in conjunction with lowering springs to better match the performance characteristics of the springs.**

#3 Perceived savings result in more costs.

Typically, the savings associated with installing springs onto stock shocks are counteracted by the need to later replace the shocks with new units, aftermarket or otherwise. If shocks and springs are replaced at one time the labor costs are combined into a single cost. Shocks will be needed sooner than normal, and the labor to install them being paid twice; once when the springs are installed, and once more when the shocks are replaced. In effect, while saving money in not upgrading the dampers, you will just be deferring the cost that you will eventually need to pay anyway, and indeed paying more by paying for labor twice. Save if you gotta. Do the shocks at the same time as the springs.

So, that’s my story. I’m stickin’ to it. Besides the fact that the stock shocks are not designed to accommodate the lower ride height of sport springs, they are often valved wrong and will not provide the performance or longevity you expect from a sports suspension. You’ll end up replacing the dampers sooner and pay more labor in the end.

* Note that Tein coil-over damper kits all have short-case dampers and are designed to work at reduced ride heights without bottoming. They provide ideal travel, ride, and handling characteristics; all of which we strongly recommend for street sports driving. These kits are also adjustable for a range of ride heights, along with options such as firmness adjustability and rigid upper pillow mounts.

** We strongly recommend either Koni (twin tube) or Bilstein (monotube) dampers be used in conjunction with any aftermarket spring, soft, stiff, low, mild, etc. Koni Yellows have the advantage of adjustability to tailor them to nearly any given spring available. Bilsteins offer a monotube design which is an upgraded design over twin tubes that provide better driver feedback, response, and accuracy.

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