A shock dyno is a testing machine that measures how much damping force your shock produces as it moves through compression and rebound. We move the shock at controlled speeds, record the force it creates during the test, and display the results on a dyno graph.
That graph gives you an actual measurement of shock performance. Instead of relying only on a driver saying the car feels different, you can compare the shock against an earlier test, another shock, or the force range it was built to produce.
A shock dyno doesn't replace track testing or driver feedback. It gives you data that helps explain that feedback. It can show whether a shock is performing consistently, whether an adjustment changed the damping, and whether service restored the shock to its intended performance.
This guide walks through how a shock dyno works, what the graph tells you, and when your shocks should be tested. If you'd rather skip straight to the equipment and testing options, our dyno products and services page covers both.
A shock dyno is a piece of test equipment built specifically for shock absorbers and struts. We mount your shock in the machine, move it through a controlled cycle, and measure the force it produces as it resists that movement.
The main result is usually a force-versus-velocity graph. It shows how much damping force the shock produces at different shaft speeds through compression and rebound.
This matters because you can't see damping force by looking at the outside of a shock. Two shocks can look identical and still perform differently because of their valving, adjustment settings, oil condition, gas pressure, internal wear, or service history.
A dyno gives you a measurable record of what each shock is actually doing. We call that record an assurance of quality, because it verifies how the damper behaves through its complete motion cycle. Every shock we manufacture is dyno tested so its performance is confirmed before it ever goes on your vehicle.
That original test also becomes a baseline. If your car starts handling differently later, we can test the shock again and compare it with the earlier graph. You're not left guessing whether the shock changed.
The same principle applies after an adjustment or rebuild. A new dyno test shows whether the work produced the result you expected.
A shock dyno works by repeatedly compressing and extending your shock through a controlled stroke.
The shock gets secured between mounting points on the dyno. The machine moves one end while the other stays attached to a load-measuring device. As the shaft moves in and out, the dyno records how much force the shock creates while resisting that movement.
When the shaft moves into the shock body, the shock is in compression. When the shaft moves back out, it's in rebound. We measure both sides of the cycle, since a shock can produce very different amounts of compression and rebound force. Depending on the equipment and the test being run, we can control shaft velocity, stroke length, the number of cycles, adjustment position, test temperature, and test duration.
A common crank dyno uses a rotating mechanism to move the shock through a repeating stroke. As the crank turns, the shaft accelerates from a stop, reaches its highest speed near the middle of the stroke, and slows again before changing direction. That lets the dyno collect force measurements across a range of shaft speeds during one complete cycle, and the software organizes those measurements into a graph. The Roehrig-inspired SYD line we supply is the machine most teams picture when they think crank dyno.
A 2HP dyno is ideal for most racing applications. If you're testing higher forces and velocities, like what you'd see in off-road applications, a 5HP or 10HP model gives you that added capacity. Our own S-Link PHD-2 covers the first case, and the full range sits in the dyno products collection.
The speed being measured is the speed of the shock shaft, not the speed of your race car. Low shaft speeds usually come from body movements such as roll, pitch, squat, and brake dive. Higher shaft speeds are commonly tied to sharper inputs like bumps, potholes, curbs, or rough track surfaces.
We also offer more than a simple repeating crank cycle. Alongside basic crank-dyno testing, we run custom endurance and track-simulation testing through more advanced testing equipment. Those tests can repeat more complex movement patterns or run the shock for longer periods to examine consistency and durability.
For a basic dyno test, though, the process is straightforward: move the shock in a controlled way, measure the resistance, and record the result. We test at consistent conditions, including temperature, since shock oil behaves differently as it heats up and inconsistent test conditions make two graphs hard to compare fairly.
A shock dyno graph is a visual record of the test, and it's the main way you actually see what the dyno measured: the force your shock produces at different shaft velocities, along with how that force changes through compression and rebound.
Our commonly used force-versus-velocity format places compression and rebound on opposite sides of the graph. Positive force values represent compression and negative values represent rebound. Shaft velocity runs across the horizontal axis. The farther a line moves away from zero force, the more damping force the shock is producing at that shaft speed.
The low-speed portion of the graph relates to slower shock-shaft movement, and it's often important for controlling chassis movements like body roll, brake dive, acceleration squat, weight transfer, and gradual pitch movement. The higher-speed portion relates to faster shaft movement created by sharper inputs, including bumps, curbs, potholes, and rough surfaces.
Low-speed and high-speed don't describe vehicle speed. Your race car can be traveling very quickly while the shock shafts are moving slowly through a gradual corner. It can also be moving at a lower speed while a sharp bump produces high shaft velocity.
A graph can display several runs at once. We can test a shock with the adjuster fully open, at a middle setting, and fully closed, and the resulting lines show you the available adjustment range. That range is set by internal parts like the adjustable needle, which is why two shocks with the same click count can still behave differently. We can also place graphs from two shocks on the same screen, which makes it possible to compare them throughout the tested velocity range instead of relying on one force number or a simple valving label.
The shape of that curve tells a technician a lot, which is exactly what our dedicated guide to reading a shock dyno graph breaks down in detail, including the quadrants, opening and closing portions of the cycle, and how the curves connect to setup decisions. For this piece, the important point is simpler: the graph shows how much force the shock produces and how that force changes with shaft speed.
A dyno is only as useful as the software driving it. The machine produces the movement and the measurement, but the software runs the test, stores the result, and gives you a way to work with the data afterward.
PASS, the Penske Analysis Software Suite, is our shock dyno software platform. It was built by Penske Racing Shocks alongside the original software author behind Roehrig, and it covers three jobs in one connected workflow: run your tests, analyze your data, and predict your settings.
Run your tests. PASS controls the dyno and captures the data in the same workflow, so setting up a test and recording the result aren't split across separate tools.
Analyze your data. You can open, compare, and analyze runs going back years. That's what makes the baseline idea in the section above practical. A graph from three seasons ago is only useful if you can actually pull it up next to the run you finished this morning.
Predict your settings. PASS uses machine learning to model a damper before you build it, so you can work through a valving direction on screen instead of building, testing, and rebuilding to find out.
For teams already running Shock 6, PASS opens your existing files and runs on the dyno hardware you own now. After MTS acquired Roehrig, racing-side development slowed, and PASS is the modern replacement built specifically for race teams rather than general lab testing.
PASS is rolling out in stages through 2026 with a wide release at PRI in December. Beta access is open now, and it's aimed at race team damper engineers, shock builders, independent racers with their own dyno, and university and OE testing programs.
Shock dyno testing matters because it gives you a repeatable way to verify performance. Without dyno data, you may know your vehicle feels different, but you may not know whether the shock is responsible. A graph helps narrow that question by showing whether the shock is still producing the damping it should.
It establishes a baseline. A baseline is the dyno record of a known shock setup. Once you have it, we can compare future tests against it. If the shock loses force, becomes inconsistent, or changes shape in one part of the curve, that difference becomes visible. That's why we stress the importance of having a dyno graph for your shocks. It validates the setup you're actually running.
It catches problems you can't see from outside. A shock can look fine on the outside even if an internal problem is affecting its performance. A dyno can reveal a loss of force, inconsistent runs between repeats, a narrow adjustment range, or a difference from what the shock was built to do. That gives us a reason to inspect the shock rather than sending it back out based on appearance alone. It might show lower force than the baseline, an adjuster that doesn't produce the expected range, a difference between shocks that should be similar, or performance that changes too much as the shock heats up.
It confirms the intended relationship between shocks. Not every shock on your vehicle should necessarily produce the same curve. Your left-front and right-rear shocks may have different jobs and intentionally different builds. Dyno testing confirms whether each one matches the spec it was supposed to have, and if two shocks are meant to perform similarly, the data shows exactly how closely they compare.
It verifies setup changes. When we change valving, bleed, a piston, or an adjuster setting, the dyno shows what that change actually did. The result might confirm the increase or decrease you expected, or it might show the change affected a different part of the curve than you thought. That helps connect shop changes with what your driver is telling you at the track.
It validates shock service. A rebuild should do more than replace oil and seals. We run a pre-service dyno test to measure how the shock arrives, then a post-service test after the rebuild. That comparison shows whether service actually restored the damping and gives you documented results instead of an assumption that the rebuild corrected the problem.
That said, a dyno won't automatically identify the exact failed component. We may still need to disassemble the shock and inspect the oil, seals, shims, piston, shaft, adjusters, and other internal parts. It also can't prove that every handling complaint comes from the shocks. A loose car, tight car, harsh ride, loss of grip, or inconsistent balance can just as easily come from tire pressure or condition, alignment, spring rates, ride height, suspension geometry, chassis condition, aerodynamics, or track conditions. What the dyno does is help eliminate or confirm the shocks as a possible source of the problem, which can save considerable time. Instead of changing several parts of the chassis while an underperforming shock stays on the car, you can test the shock first and make a more informed call.
A shock dyno tests the shock in a controlled environment. It doesn't test your complete vehicle.
The machine can't feel what your driver feels, account for every change in track conditions, or tell you which complete chassis setup will produce the fastest lap. It doesn't replace track testing, either. We treat the dyno graph as a setup guide, but the best way to finalize a shock setup is still to test the vehicle on track and fine-tune it under real conditions.
A standard crank-dyno cycle also doesn't perfectly reproduce every movement your shock experiences during a lap. Real shock movement is affected by the track surface, tires, springs, suspension geometry, aero load, driver inputs, and the rest of the vehicle. Our more advanced endurance and track-simulation testing can reproduce more complicated movement patterns, but even that data still has to be connected with vehicle testing and driver feedback.
The graph also needs to be read correctly. A large damping-force number isn't automatically better than a smaller one. The right curve depends on your vehicle, spring package, tire, track, driver, and what that shock is actually built to do. The dyno gives you accurate information about the damper. You, or we, still have to use that information to make the right setup decision. Our videos and webinars and downloadable resources go deeper on the interpretation side.
Your shock should be dyno tested any time you need to verify its current performance or compare it with a known result.
Before a new shock is used. Testing confirms the shock performs to its build spec and establishes the original baseline. We test every shock we manufacture before it goes to you.
Before and after service. A pre-service test shows how the shock is performing when it arrives. A post-service test confirms how it performs after cleaning, inspection, replacement parts, fresh oil, and reassembly. The two graphs give you a documented comparison of the service result.
When your vehicle starts feeling different. If your driver reports the car has become inconsistent, lost grip, or reacts differently to the same setup, a dyno test can help determine whether the shock changed.
After a hard impact or off-track event. A curb strike, crash, heavy landing, or off-track excursion can damage or change a shock even when the outside doesn't show an obvious problem. Testing verifies whether it's still producing repeatable damping.
After a valving or internal setup change. Any internal change should be tested to confirm it produced the force curve you intended. That includes shim stack changes, a new piston, or a different bleed configuration.
When comparing shocks or setups. Dyno testing lets you compare different valving packages, adjustment settings, or shocks built for specific tracks and conditions.
When creating a new baseline. If you don't already have graphs for your shocks, testing gives you a starting point for future service and development decisions. And if you're testing often enough that access itself is becoming the bottleneck, that's a different conversation worth having, and our dyno products page is where that conversation usually starts.
If your vehicle feels different, your shocks have been rebuilt, or you need to confirm a valving change, a shock dyno test gives you a measurable place to start.
We offer basic crank-dyno testing, custom endurance testing, track-simulation testing, shock analysis, development, revalving, and complete service. Our equipment is inspected annually to support consistent data and dependable feedback. If you're not running Penske shocks, that's not a problem either. We offer professional dyno testing for all shock brands at $100 an hour, and if you're looking to bring a dyno in-house, our own dyno products are available too, including the S-Link PHD-2 and the Roehrig-inspired SYD line.
Before you send your shocks in, gather the information that will help us understand what you need: your shock brand and model, your vehicle and racing application, the position of each shock on the vehicle, current adjustment settings, existing build or valving information, previous dyno graphs if you have them, the handling problem you're investigating, and any recent service, impact, or setup change.
You don't need to diagnose the internal problem yourself. Just explain what changed, when it changed, and what you need the test to confirm. If you're sending shocks in for service at the same time, start a shock service request so the paperwork travels with them.
Connect with our S3 team to talk through the type of test your program needs, or head straight to our dyno services page to get started. If you'd rather work through a local shop, the dealer locator will point you to one, and if you have questions about anything else, contact us directly.
What does a shock dyno test? A shock dyno tests how much damping force your shock produces as its shaft moves through compression and rebound at controlled speeds. We normally display the results as a force-versus-velocity graph.
How does a shock dyno measure damping force? We mount the shock in the dyno and move it through a controlled stroke. A load-measuring device records the force the shock creates while resisting that movement, and the software matches those force measurements with shaft velocity and position.
Why do racing shocks need to be dyno tested? Dyno testing confirms your shock performs as intended, establishes a baseline, verifies adjustments, lets you compare shocks, and shows whether service restored performance. It replaces assumptions about shock condition with measurable data.
Can a shock dyno identify a bad shock? A dyno can show when a shock has lost force, become inconsistent, stopped responding correctly to adjustment, or moved away from its baseline. It may not identify the exact failed part until we disassemble the shock and inspect it, which is part of our shock service request process.
Does a shock dyno replace track testing? No. A shock dyno measures the damper in a controlled environment, while track testing shows how the shock works as part of your complete vehicle. You get the best results by using dyno data together with driver feedback and repeatable track testing.
Should shocks be dyno tested after a rebuild? Yes. A post-service dyno test confirms the rebuilt shock is producing the damping it should. Comparing it with the pre-service test also shows exactly how performance changed during the rebuild.
What software runs a Penske shock dyno? Our dynos ship with Shock6 software, and PASS, the Penske Analysis Software Suite, is our own platform for running tests, analyzing runs, and predicting tuning settings. PASS opens existing Shock 6 files and runs on dyno hardware you already own.
Does every Penske shock receive a dyno test? Yes. Every shock we manufacture is dyno tested, and we also run pre-service and post-service dyno testing as part of our factory shock-service process.