Original JRZ designs and valving strategies have been and remain successful because the basics are what matter the most. Executing on those basics over and over for each team, car, track, and client are what keeps us producing consistent results. Focusing on these allows us to cut through noise and conjecture, and keep the effort where it makes the difference. This is where the RS Line lives and breathes and what makes it so good. Applying the basics over time allow us to highlight specifics and know when and what solution to apply in that case. This is where the motorsport line came in. Naturally, a lot different solutions emerged, and the motorsport line became complicated. So, JRZ went back to basics.
The JRZ Motorsport line used to have a lot of different numbers and damper models. While we personally enjoyed that, it was only because we we helped come up with it and knew what it meant. It turns out that most people had no idea what number went with what and the whole thing was confusing. JRZ simplified this by going with two main product lines, with upgrades & options to suit your needs. Here we will break down what those are and which choices may be best for you.
The line was changed to two main sets – 11 series and 12 series. Each has the same shaft and valving assembly, with different remote canisters. 11 series dampers come with a single, high speed blow off adjustment on the canister. 12 series dampers come with two adjustments; high speed blow off and low speed bypass. While these are feature similar to the RS Line, the difference here is in the details. Fine attention to design allows highly consistent adjustments, ranges, and side to side matching.
The shaft assemblies are where a lot of the recent developments have been. To start, the standard motorsport shaft adds a lot of refinement above the original design.
Originally, shafts were machined from one steel rod, leaving a lot of material inside and forcing most design features to be outside that volume. A two piece design allows for much more accurate adjustments due to machining tolerances and fits between the adjusting parts. A check valve was incorporated to make the adjustment rebound only, so that compression on the piston side could be better controlled. For more info on that feature, check out our post on the development of the FA 3030 piston.
A two piece design also allows for different main shafts to be used, while retaining the same valving & adjustment assembly. JRZ standard shafts in the motorsport line are 22mm in diameter, in line with their creators vision. Increasing the shaft diameter to 25mm is considered a requirement in most strut applications with heaver cars. Larger diameter makes the shaft much more resistant to bending, reducing operating friction and keeping camber compliance. More importantly, the area of the shaft increases about 30%, making the canisters that much more effective. There is more lifting force from the gas pressure along with more sensitive low speed and a larger range of high speed adjustment.
Alternatively, different adjustment assemblies could be placed in that same shaft housing, allowing further versatility. JRZ designed the 50 DA to fit this bill. While the standard motorsport shaft has an isolated rebound adjustment, the 50 DA has both an isolated rebound and isolated compression adjustment. Upgrading to the 50 DA makes an 11 series a 3 way and 12 series a 4 way.
So, which one is right for you?
Standard configurations:
11 series is when you want a lot of options but can only go 2 way per rules. Choose the 12 series when you want a predictable, easy to use, high performing 3 way option.
Upgrading shaft size:
25mm shafts: Almost always in front strut applications like Porsche, BMW, Mustang, etc. For example, we may recommend upgrading only the front in a 911 GT3, leaving the rear to have more area for the main piston to work. Heavier applications and “safari”/”overland” applications benefit from this as well.
50 DA:
When you want the best, most customizable system. Requires good knowledge of the rest of the chassis setup to get the valving right the first time. Adjustments are more challenging, each click is a smaller increment, so knowing how many to do is more important. Note, we recommend upgrading the 11 series rather than the 12, as in most cases, 3 compression adjustments are extraneous.
Choosing the right package is important and we are here to help, contact us with your specific needs and we’ll put together a turnkey solution.
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Learn about the JRZ RS line here. You can also learn about the JRZ AT Pro line here.
