FC need for Rear CA Spherical Bearings?
 

Of course these would be put in with adjustable toe links.

In straightforward terms, what would this mod be worth (in reducing times) on a road race car putting down 400 RWHP?

I hear this is a good mod to reduce rear toe flex but what is it worth in reduced time?

I don't want to outline all of my existing mods on my suspension but as far as I can tell, I have every one available and this is the only one left I could do and state that so we stay on subject.

Thanks all,
Ben

They won't directly lower lap times but they should make the handling more consistent which will lead to improved times. If you have the dogbone replacement camber adjusters they are also needed to reduce binding in the suspension.

Noted on the binding. However, I have both types of camber adjustment and cannot tell if I am getting binding. Actually, i did not ajdust the single camber rod because I didn't want to bind my MMR UHMW subframe bushings but now you are making me think I should adjust that first and go with my dogbone adjustments second.

Ben

You can use the spherical control arm bearings and NOT have to use the adjustable toe link kit. The toe would be adjusted with the stock cam bolts, I used to do it that way and it worked fine. I since have gone to the adjustable toe links. These are hard to measure in lap time drops, it's not like better gearing, more HP or wider tires. It will give for more consistent handling as stated above. I say do it, might as well finish off your suspension.


My rear suspension mods...

Mazdatrix subframe
AWR single camber
MMR individual camber
AWR spherical control arms
AWR toe links
Mazdaspeed aluminum DTSS
Custom delrin/stainless upper hub bushing

What is modified with this? I didn't see it on their website.

I should have typed more ... Mazdatrix Delrin Subframe mounts

I just installed a set of the rear spherical bearings. Got mine from MMR. Previously, I ran just the single camber adjuster but the right and left rear camber never matched. I then switched to the AWR individual camber adjusters. With these I was able to get the left and right cambers to match. Unfortunately, I did not know about the binding issue. I forgot that I had done derlin bushings in the control arm a long time ago. On the track, I could tell that there was something amiss in the rear. It was still drivable, just did not feel right. Also you could just tell by just rolling the car around, the rear would squeak and "bind". After switching to the spherical bearings, the rear feels normal, like it did before the camber adjusters. No more squeaking when I roll the car around too.

So if you are running derlin bushings out back and the individual camber adjusters, you definitely should get the spherical bearings. Don't waste your time like I did!
If you've got the regular bushings in back you might not need them

-Jack