Insight - I just bought a new set of shocks, what do I do? Part #1

By: Admin

You’ve done your research, talked to the right people. American Express can verify you’ve bought the set of shocks you think will make the difference. The local delivery truck has put it in the hands of the person putting it on the car. Everything is aligned, balanced, fueled, clicked, and pressurized. Sitting track side with everything ready to go, you think to yourself; now what?

People refer to suspension setup and tuning as a “black art.” It is more that we do a lot of work with limited information. Fortunately, I see this phrase being used less frequently as time goes on. More and more people are starting to understand the mechanics. Over the years a lot of people have written and disseminated a lot of great technical information on the topic. We won’t rehash those details here, we’ll figure out how to use them. I don’t purport to be as smart as those authors anyway. Keep it basic and keep making steps, the right direction will show itself to you.

In this series we’ll go through the basic process of setting up a new set of shocks. This can be applied to a brand new out of the box set, a “new-to-you” set, or as a refresh of a current car. Here are the steps that will be covered:

  1. Hit the basics – build from a solid foundation
  2. Get a feel for it / Starting from scratch – testing and development isn’t about the absolute lap
  3. Moving from the baseline  – take a step, see if it is the right direction
  4. Repeat – Keep moving using steps 1-3 with intelligent choices
  5. Get some help – If you are in a loop, get a detached perspective to break out

Part 1 – Hit the basics


Tire pressure

Tire pressure
Tire pressure controls more variables with one small measurement than anything else in the chasis.

Nothing is more basic when it comes to handling and performance yet I do see it overlooked with a disturbing frequency. Here is what matters; hot pressure. That means be diligent about knowing what to fill the tires with (nitrogen unless you’re getting fleeced at the dealership), setting the correct cold pressure (varies with outside conditions), bringing them up correctly (no 1st lap heroics, but work them), and bringing them in hot. You won’t get a good read with long cool down laps. If this is off everything else is effected negatively and this has been the source of many an erroneous finger point. You cannot be too specific about tire pressure.





Alignment and chassis setup

Setting up a new set of shocks - Alignment and chassis setup
Spend good money once, instead of over and over.

When the tire pressures are square, we move on to the chassis. A solid setup with strings or a motorsport grade set of fixtures makes a world of difference. The level of accuracy you get there makes a discernible difference at speed and load.  Like investing in a good mattress, get your chassis squared by an expert. This also applies to the spring and sway bar setups. Fortunately I have been around some very talented and well trained people who have shown me the right way to do things. When the springs and perches are properly set with even heights left to right, and the sway bar neutralized, the difference is night and day. I have personally chased so many problems on corner exit due this.



Damper gas pressure

Damper gas pressure
Cheap head scratching insurance

Generally, this should be set before alignment, but it is not as important, so I put it after. Anyway, if your dampers have adjustable gas pressure then you want to set them in the proper way. This should always be done at full extension, meaning the car is up in the air. Having the suspension at full extension ensures that there is the most consistent gas volume in the dampers left to right. Just like the chassis setup, if the gas pressures start out off, you can feel it. Note that dampers get hot out there, making the pressure rise. Anything off when they are cold, gets even more off when they are hot.





Spring choices

Setting up a new set of shocks - Spring choices
Don’t sweat these too much, there are a few laying around

I’ve long said for most levels of racing (even in the pros at times) spring rate choices are kind of like ice cream. Everyone has their flavor and there is no absolute “right” answer. What works for you may not work for others. Certainly drivers have been in cars at the top of the charts battling it out in the same base chassis with completely different spring rates. The mathematical purists out there may go on about the “optimal” rate but I also don’t see them with an “optimal” trophy shelf. Essentially, start out with a spring rate choice in the practical range and if you know enough about your driving style, adjust by some percentage. For example, if the “go to” rates are 500 front and 700 rear, but you like to feel chassis roll, take out 15% and start with 425 front and 600 rear. After all, springs are the cheapest part of the suspension and relatively easy to change.



Don’t overthink a shitbox

Don't overthink a shitbox
“I spend all this money on shocks and this thing STILL drives like shit”

I have seen too many owners throw money at poor preparation and skimped efforts. The job of the adjustable damper is not to cover up for a half-assed effort at the chassis shop. In this article we cover basics from a setup perspective, but don’t forget the rest of the forest. If your car doesn’t have the rest of the basics sorted, don’t spend your money on “quick fixes” like adjustable dampers. Turning a knob is accessible, easy, and gives instant change. For that reason it is often a misused tool.


Next up: Part #2a – Get a Feel for It – Recommended Settings

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