robrob

Nope, I'm the one that was confused. I thought you were talking about the front roll center adjusters. I've never seen anyone offer multiple offsets for roll center correction but if you really feel the need for rear roll center adjusters I'd recommend the shorter 12mm adjuster. The 20mm adjuster would probably firm up the rear roll too much.

helpslows2k

thanks! pls let me know. will wait out before i decide to pick up the js item

robrob

Keep in mind that installing the roll center adjusters in the rear will firm up the roll similar to going to a stiffer rear sway bar which is opposite what is normally needed. That's why the Miata rear sway bar is a popular mod.

The front roll center adjuster is normally a good idea because the S2000 typically needs a pretty big front roll bar.

sweetdill

OP, helpisfinallyherealbeitratherslowly,

Here we go, Hardrace vs. OEM:




The height of the OEM body is 18mm from where it bottoms out in the knuckle to the bottom* of the contact surface, and 23mm to where the boot starts.
*Obviously the ball joints are upside down in these pictures.


TheHardrace body is 33mm from where it bottoms out to the locking ring.


The Hardrace spacer is 15mm tall, which makes sense as 18+15=33.


Here is a comparison of the OEM on the left, and the included Hardrace castle nuts.
People have been having issues with their cotter pins missing the slots in the Hardrace castle nut entirely.
At least in the rear, the thread pitch and hardware size is the same, so using the OEM castle nut might be an easy fix.


If you are really low, keep in mind that for a given ride height, the roll center adjusters will increase your suspension travel, I don't know if the extra 5mm The J's offer over the Hardrace is worth it for you.
Also each post on the different brands of ball joint will settle into the lower arm at slightly different heights.
I went with the J's 12mm in the rear of my S2000, seems great, I love how my car drives on track, never bottoms out, but I have Tein SRC and they're a pretty short shock.

Here's some pics installed and other perhaps pertinent stuff:



J's vs. Hardrace new in baggies.



J's 12mm rears installed.


Fronts installed.


Hope it all makes sense and helps.

Dylan

helpslows2k

Rob - Do you care to elaborate? That the S2k will benefit from more roll in the rear? Appreciate your comments. I've admittedly not had the chance to test the car with and without the RCAs to prove they are of any meaningful benefit. Admittedly my car is pretty stiff as we speak 18kg/mm springs all round, cusco swaybars front and rear. I am however running full dunlop slicks 240 front 265 in the rear.

helpslows2k

Dylan. That is very useful. Thank you very much.

helpslows2k

btw how do i post pics? It seems i can only post html links to images. Thanks!

robrob

The normal setup for fast track S2000s consists of a big front sway bar and the stock rear sway bar or a softer Miata rear, or even the rear sway bar disconnected or removed. Adding roll center adjusters to a lowered S2000 essentially stiffens up the roll axis. The rear of the car normally doesn't need a stiffer roll axis but roll center adjusters in the front make sense, you can run your adjustable sway bar at a softer setting after the install which gives more suspension independence.

sweetdill

I just use the [img] code with the image address from my photo bucket account.
If you pay for the membership you can use attachments.

helpslows2k

Thanks guys for all the tips. Ive gone ahead to order the js rca as i needed a replacement for the ones i already had on the car ( the old ones were installed so long ago i dont even know their origin)

Id try running the car on a looser swaay bar setting to see if there is an improvement in lap times. How do i tell if the rear is too stiff on roll?