JRZ RS1 coilovers installed on Racecomp BRZ (and other RCE updates)

[der_rainman]

Subscribing! Tasty looking parts!

[yomny]

After reading around and doing some research on different coilover sets i was puzzled by why some of the most expensive or high end assemblies don't adjust height using the shock body, instead the spring threads up or down. I could be wrong and im only basing this on pictures i've seen around. The AST seem to 4100 series seem to adjust by lowering or raising the spring perch and now these JRZ seem to be the same way. Is it favorable to leave the preload/shaft travel alone by adjusting height using the shock mount? Please enlighten me, i know there's something im missing here.

[Racecomp Engineering]

Dual height adjustable coilovers (where you adjust height with the lower mount, not the spring perch) are always talked about as the "right" way or the number 1 feature to have in a coilover. In theory it can be a good thing. In practice it is more often a cost saving measure marketed very well.*

You do have the advantage of not losing bump travel when lowering the car. That is pretty cool. BUT....with many of them you start out with so little to begin with that you only come out ahead if you're really slamming the car.

Single adjustable coilovers (usually) are already shortened quite a bit to get you lower from the start. They're designed that way from the start around a certain lowering range. Someone posted a picture of KWs vs the stock struts and it's a great example. The KWs look like a dual height adjustable coilover that's already been spun down to a lower ride height, but with much more total stroke. So you end up with a bunch of bump travel AND some droop travel.

Dual height adjustable coilovers without helper springs have only as much droop travel as the weight of the car compresses the spring. Not very much. Single adjustable coilovers can have plenty with a helper or tender spring.

So...single height adjustable coilovers do trade bump travel for droop travel when you lower the car BUT they generally start out with much more and for a given ride height (not slammed) you will have more bump and droop.

And if you're running helper springs, you aren't actually preloading the main spring.

Notice that JRZ, Moton, AST, KW competition, etc. all run single height adjustable coilovers. They're designed around an intended ride height range and they work very well. Ohlins goes both ways. Tein and Cusco and most JDM companies run dual height adjustable coilovers. It's not inherently bad and it IS sometimes applied correctly. But it is not the only way to do things.




*Generally the lower end coilovers do have this feature and it is done so that the same damper insert can simply be threaded onto different lower mounts and used for a variety of different car types. Great if you're mass producing a bunch of coilovers at dirt cheap prices, but not great if you want a damper built around your specific car and want to go fast. So it's often (but not always) a sign of valving that's generalized for multiple cars and not just one. And I've seen proof that a certain lower-end company uses the exact same damper insert and valving for Subaru Impreza WRX, STI, Mitsubishi EVO 8/9/X, and Subaru Legacy.


- Andrew

[yomny]

The missing link lol, i really appreciate the lighting fast response and detail in your explanation. I do recall seeing a lot of comments on a small amount of shaft travel with most of the dual adjustable coilovers. I knew something was key to using single adjust on these high end companies and that is they're already shorter to give an adequate drop plus they have a lot more travel than the others! I wanted something that was done right from the beginning and these JRZ seems to be around there. The JRZ's you offer dont have adjustable upper mount so we will need to re use the oem mount? Thanks a lot for your expertise.

[Racecomp Engineering]

No problem! They do not come with camber plates. We offer them with the Whiteline Com-C top mount which is a fixed camber/caster plate, but we can also pair them with camber plates. We've got a couple options and can ship them assembled and ready to pop in.

- Andrew

[86design]

very nice

[pdreams]

Originally Posted by Racecomp Engineering

No problem! They do not come with camber plates. We offer them with the Whiteline Com-C top mount which is a fixed camber/caster plate, but we can also pair them with camber plates. We've got a couple options and can ship them assembled and ready to pop in.

- Andrew

Hi Andrew,

I got the reply and advice from Myles regarding the JRZ and KW. I have my decision and am planning for something for myself by year end.

Thanks for all the time and effort from all of you at Racecomp.

Cheers

[Racecomp Engineering]

Anytime. Glad to help.

- Andrew

[VSGTS14]

for anybody who doesn't know about RCE, they make the best suspension parts available for the subaru world.

excited to see what's released for the brz/frs. i already saw some of your posts on iwsti with your car.

[yomny]

Racecomp have PM!

[Duo]

Originally Posted by yomny

Racecomp have PM!

Ditto!

[Duo]

Originally Posted by Racecomp Engineering

- Bilstein testing also coming eventually.

Without giving too much away, are these shocks or coilovers?

[Racecomp Engineering]

^ Coilovers first.

[Duo]

Originally Posted by Racecomp Engineering

^ Coilovers first.

Copy that!