What is K&C Testing
Morse Measurements Frequently Asked Questions
1. What does “K&C” stand for?
“K&C” stands for “Kinematics and Compliance.” Not to be confused with “KnC”, nor is it the “KFC rig”, though that would be tasty. But seriously, “kinematics” refers to suspension geometry. For the engineers, this is rigid body kinematics. “Compliance” in this case is the inverse of stiffness. It refers to how the suspension flexes or bends under load.
2. Is it a 7-post rig or a shaker rig?
K&C testing is often confused with shaker rig testing. These two types of test technologies measure different aspects of the suspension and chassis. Shaker rigs operate at high speed / frequency and apply only vertical loading to the suspension. They are often used by racers to tune dampers (shocks). K&C tests are run slowly (intentionally) to minimize inertia effects and accurately measure load-displacement relationships. K&C testing applies vertical loading along with lateral loads (cornering), longitudinal loads (braking and traction), and aligning torque (twist) at the tire contact. K&C testing measures all aspects of the suspension except the dampers. As such, the two types of test rigs are complimentary. To learn more about the differences, click here.
3. Is it like a pull-down rig?
The capabilities of K&C testing go far beyond a pull-down rig. Pull-down rigs can measure vertical ride rates (to an extent) and are good for checking clearance. However, they lack the ability to input cornering and braking forces and most provide no measurement of steer, camber, or wheel center motion. To learn more, click here.
4. Can you re-play an on-track event on the rig?
On-track events can be played back through the K&C rig at reduced speed. Full lateral/longitudinal loading can be applied at the tire contacts with the chassis moving in realistic positions and the steering robot providing driver steering input. This allows you to see true steer and camber orientations as they occur on-track. To do this type of test, you need to provide detailed data taken from the car on-track. At a minimum, this needs to include shock positions (or laser ride height) at all four corners and accelerometer measurements. No generic tracks are available, as this test is specific to the car being tested.
Although applying multiple inputs simultaneously is realistic, interpretation of the results can be difficult because of the complexity. As a result, most customers choose to run more traditional K&C tests, which most often apply one input at a time. These allow clear cause and effect to be measured and understood and provide more insight into the behavior of the suspension.
5. What can I learn from a K&C test?
K&C testing gives you insight into your vehicle’s suspension and allows you to measure things that just couldn’t be practically done any other way. Where else can you apply over 2000 lb of lateral force to the tire contact and accurately measure how much camber and steer changes as a result? To learn more about things you can learn, click here.
6. How do I know what tests to run?
Morse Measurements will help you develop a custom test plan. Just tell us what you want to know and we’ll recommend the appropriate test(s) to get the answers you need.
7. What tires should I use for K&C testing?
If you have the tires that are normally used on the car, these would be the first choice. However, if you don’t have access to these tires, as often happens in racing, you can still measure the suspension on the K&C machine. Although tire stiffness’s are measured, the primary K&C measurements are all taken from the wheel hub, so any tires may be used.
8. How do I prepare my vehicle for K&C testing?
Preparation varies depending on vehicle type. Morse Measurements will provide you with a vehicle preparation guide, specific to your vehicle type. We are also available to do the preparation for you.
9. How do you charge for K&C testing?
Most K&C tests are charged per hour at Morse Measurements. Time is counted from the time we start working on your car until the time it is removed from the rig. Some special packages are available for production vehicles that charge per K&C test, rather than per hour. Contact Morse Measurements to discuss what applies in your situation.
10. How do I schedule a K&C test?
Call or email us with date(s) you want to test. We can reserve a spot on the calendar right away. During most times of the year, tests are scheduled about a month in advance. If you need to get in more quickly, let us know and we’ll do our best to find an open day on the calendar.
11. What should I expect on test day?
Test day varies depending on the type of test, but typically the day starts with mounting the wheel measurement fixtures to the hubs and truing to the spin axes of the wheels. We will also install the steering robot, if applicable. We will then work through the process of loading the car onto the K&C rig. It will take approximately 90 minutes total to mount fixtures and load the vehicle, at which point actual testing may begin. As tests are running, we review the results and highlight any abnormalities. Real-time reports are generated as the tests are run, giving you immediate answers. Test plans can be easily revised on the fly, based on results. For full day tests, lunch is provided at no additional charge. At the end of testing, we will unload the car, which takes approximately 30 minutes. The entire process can take anywhere from ½ day (the practical minimum) to multiple days, with 1-2 days being typical. Advance planning and preparation makes test day run smoothly and more efficiently. We also provide internet access and a conference room.
12. Who uses K&C testing?
K&C testing is used by a wide range of companies and engineers involved in suspension systems. Everything from top-level professional race teams to OEMs to Tier 1 suppliers to aftermarket suspension companies. If you don’t have the engineering staff to analyze and apply this information, we can provide consulting services to be sure you get the most from your K&C test.
13. I produce aftermarket suspension parts and kits. How can K&C testing help me?
For those producing aftermarket suspension kits and components, K&C testing can validate your marketing claims. It’s easy to blindly say your anti-roll bar improves roll stiffness by 50%. K&C testing can measure the actual improvements you made. This can help in product development and will prove your marketing claims. If you are a SEMA member, click here to learn more about our SEMA program.
14. I’m a small race team. How can K&C testing help me?
K&C testing gives you a big advantage by showing you what the suspension is doing. With this level of sophisticated testing publicly available, there’s no need to guess. You can know. Here’s what top level race engineer Jeff Braun had to say about it. Click here.
15. Where is Morse Measurements located?
We are located in Salisbury, NC, about 35 minutes northeast of Charlotte off of I-85. Take exit 72, the Peach Orchard Road exit. Go east on Peach Orchard. Take the first left onto Porter road, which runs adjacent to the highway, and then turn right into the Speedway Business Park. You’ll find us on the left hand side.
16. What other services does Morse Measurements offer?
In addition to K&C testing, Morse Measurements offers measurement of suspension coordinates (CMM), damper characterization (off vehicle), engineering consulting, simulation software support, and K&C seminars. Click here to learn more.